setting Arcturus: "the ghost of the summer Sun"

Event Date: September 7th
Time: 10:00 PM


Brief

   Arcturus is a little over 19º in northern declination.  Although it sets almost four hours after our Sun, that changes by about 2 1/2 minutes a day at this time of year: the Sun sets about 1 1/2 minute(s) earlier each evening as we approach the September equinox, and Arcturus sets slightly less than 4 minutes earlier.  As shown below with a dark sky, we show Arcturus about 2 1/2 hours before it sets.  The celestial equator and grid are present to clarify its declination.  The set Sun is losing declination quickly, now much closer to the celestial equator than Arcturus.

click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

As a result of this gap between sets decreasing quickly between mid August and early October, it seems as if we see Arcturus at about the place in the sky for a few weeks, and then a little lower a few weeks after that.  It isn't until about mid-October that the gap starts to increase again slowly, that we start to have less time to view Arcturus.  With this in mind, along with the Sun being the same declination as Arcturus at Summer's midpoint in late July-early August, there is a coined description for Arcturus: at this time of year, it is called the "ghost of the setting Sun".  After all, Arcturus is orange, which is a little cooler on the temperature scale than our yellow-white Sun.  Also, as a point in the sky instead of a 1/2º disc, it makes us think that the Sun has gone away, and this is what is left as its ghost.

north celestial pole view: now and in 87+ years!

Event Date: September 6th
Time: 9:00 PM


Brief

   Yesterday, I featured Polaris and the north celestial pole (n.c.p.) when talking about the Big Dipper.  Although the Dipper stars of Dubhe and Merak point almost in the direction of Polaris when a line is drawn through both, that same line to the n.c.p. is not quite as direct.  As the first image shows zoomed in with a 1.4º field, Polaris is shown at the edge (circumference) of this field.  Take a look, and the other stars when viewing with a dark sky.  Polaris is precisely 40.9 arc-minutes from the celestial pole...or is it??  See the detailed section for more on that!

Detailed

As hinted above, Polaris is not always the same separation from the n.c.p.  We can recall what I said about precession during the spring, meaning that as all other stars are doing, Polaris is changing in declination slightly each year, over the course of about 26,000 years.  In September 2099 for example, Polaris will reach its maximum declination of 89º 32 527', which according the software, is the highest numerical value.  This will put it less than 28 arc-minutes (1/2º) from the n.c.p., and make those aligning their telescopes most happy!  That is, using it as a guide star in an eyepiece that shows a dim field of stars, it helps recognize patterns closer to Polaris, and getting as close as possible to the n.c.p. before doing any further star aligning; such is common with go-to telescopes.
For the fun of it, I will show the image for September 14th, 2099.  This date and the 28th of that same month of that year, have Polaris at the aforementioned peak-declination, or very close to it both times anyway. 

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Notice the position difference of Polaris, using the same field as in image one.  For the first one especially, with Polaris barely within the field, can you recognize patterns that will help find the pole?  It is labeled in that image, yet not the second one, since Polaris is closer.  Eyeballing the field in image two however, do you notice which star shown is closest to the n.c.p.?

morning Big Dipper: getting higher

Event Date: September 5th
Time: 6:00 AM

Brief

  Shortly before Sunrise at this time of year, the Big Dipper's "cup" makes a return in the low northeast skies, while its handle becomes more visible with each passing morning.  Depending on how much obstruction there is towards your horizon, we may see the Dipper before Sunrise as early as mid-August.  When looking from a high elevation such as a mountain at mid-northern latitudes, the circumpolar asterism never sets at all.  Because of atmospheric pollution however, it isn't as easy to see when low towards the horizon, so many viewers don't really take notice of it until it starts to stand on its handle. 
Here is the Dipper during twilight, shortly before its stars are washed out by the Sun's light.  The north celestial pole is marked also, to show the Dipper's northern declination.

Detailed

   The more north a viewer is, the more hours (s)he sees the Dipper easily.  From the celestial equator, the Dipper spends about half the day below the horizon.  The further north one goes of mid-latitudes, the longer it can be seen.  Now that we have longer nights as we approach the September equinox, it gives plenty of chances to enjoy viewing the Dipper and--if dark enough with no Moon in the way--dim galaxies with a powerful enough telescope nearby it.  When we start having the Dipper higher in the sky during fall mornings and later Sunsets, I will pick an evening to label those.
This second image is at the same time as the first, although this time, I will take away the landscape, showing only the horizon line and celestial grid.  I will also label two stars of the Dipper--Dubhe and Merak--that point almost directly to Polaris: the brightest star of the Little Dipper, and parent constellation Ursa Minor, being the bear's tail. 

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

   Dubhe and Merak get some good attention this way; they are often the first stars to learn about when trying to (1) distinguish Polaris from other similar magnitude stars in that part of the sky, and (2) finding as close to north as possible.  Since Polaris is about 40 arc-minutes away from the north celestial pole (labels overlap), it is not precise, yet close enough.  More on Polaris and the north celestial pole tomorrow, when I zoom in on the surrounding star field.

Venus nearing the Beehive...just to pass

Event Date: September 4th
Time: 5:00 AM


Brief

   About an hour and a half before Sunrise, Venus is already high enough in the east.  During the early summer, we saw it near two star clusters in Taurus: the Pleiades and the Hyades.  Both are popular for astronomers, for being visible to the unaided eye, and their appearances that way: the Pleiades often mistaken for the Little Dipper, and the Hyades being a wide V shape.  There is another open cluster that Venus sometimes gets as close to as we saw it get to the Hyades, and it is approaching that cluster over the next several days: the Beehive.  Shown below, we find that being only 1º 20' from the ecliptic makes the Beehive a regular target for planets such as Venus and Mercury; both have constantly moving orbits on either side of the ecliptic--seen from Earth anyway! 

click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

At magnitude 4.0, the Beehive requires a much darker sky to see; with such, the cluster looks more like a smudge.  If using binoculars or a low-powered telescope, the Beehive's many, many stars resemble "bees swarming"; in this case, near or around a hive.  If the timing is right, the planet can go very close to--if not directly through the center of--the cluster.  For this to happen, we need to be in a position looking towards Venus when its orbit puts it in line with the cluster the same time that we see the planet go in front of it.  There are times when the orbit is perfectly placed but the planet is still a few--if not several--degrees away; that is the case this time, meaning that Venus and the cluster's closest encounter in a little over a week will have them paired well in a wide-field telescope, yet not showing Venus occulting any bees...er, stars!

both triangles--morning sky panorama

Event Date: September 3rd
Time: 4:17 AM

Brief

We are 5 mornings away from a very fine sight.  That is, for most of August, I have talked about the "2nd/other triangle" in the east, while our main Summer Triangle of (V)ega/(D)eneb/(A)ltair. sets earlier each morning in the northwest.  (V)enus/(J)upiter/(S)irius have been changing triangular configuration daily as Venus has separated from Jupiter.  Although Jupiter has changed separation from Sirius, it has been much slower than Venus, which moves much faster than prograde than Jupiter.  Getting back to the aforementioned 5-morning forecast, this V/J/S triangle will look more and more isosceles.  It is larger than the size as V/D/A, with current separations of 39º, 42º, 47º (V/S, V/J, J/S respectively).
   Below is a 180º full-zoomout of the sky, to display both triangles.  This interesting feature of the software lets us see the triangles at the same time; our normal vision of 100º doesn't let us do this normally.

click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

   The V/D/A stars have separations only as large as 38º (V/A).  If you have looked in the sky at V/D/A and imagine it about 25% larger, that is about the size of V/J/S.  Also, since Altair now is low in atmospheric pollution as early as 4 AM, Sirius is just starting to rise at this time.  For how many minutes can you see all 6 stars while Sirius and Altair are low?  Vega is about as low as Altair, yet sets a little later being further north.  At the time above, Altair and Sirius are about the same altitude.  Now that they are rising before twilight, both may be easy enough to see with binoculars, even with heavy atmospheric pollution.
   Keep watching V/J/S, as Venus continues to pull away from both slightly.  Can you see how two "sides" are starting to look the same "length" as a result of the separations?  Look closely, and use your fist stretched out at arm's length if that helps measure them.  Remember that a fist is about 10º held out this way, with each knuckle about 2º.

Mars pulls further from Saturn, Spica

Event Date: September 2nd
Time: 8:00 PM


Brief

  Here is a quick look at the Mars/Saturn/Spica grouping...or what was!  Mars has continued its separation from the other two, while much slower moving Saturn, has stayed close enough to Spica to easily fit in a binocular field with the star: just under 5º separated.  Since we have had the Sun setting more than a minute earlier each day the last several days (and continuing at that rate on average for this month), it has meant that we have been able to see the trio before they get too low to the horizon.  Here they are, with Mars already separated from Saturn by 10º.  Less than three weeks ago, they were in a nearly straight line, which just goes to show that as we move further from Mars in our orbit, that we see it moving against the stars faster as well.

click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

   Although we are further from Mars each day, we don't see it change it phase much as we do with the inner planets; there is some wax and wane as our position with Mars changes, although it is minimal compared to the the crescent phases that we see of Mercury and Venus.  With Mars, when it starts to approach the other side of the Sun, we still have a lit side facing us, as it only has superior conjunction and not inferior.  With the latter, in the case of Mercury and Venus, we are seeing the shadowed side of each, opposite the Sun as they go between us.  However, as we see with Mars and less so with each outer planet the further we go through Neptune, a hypothetical viewer on each of the inner planets facing Earth would see a certain percentage of wax and wane throughout the viewing of Earth.  Since we will never find ourselves on either planet, I will hold off from showing images from that, yet it is a very similar concept as from Earth viewing Venus and Mercury.  If viewing Saturn through Neptune from here, the change in phase is minimal enough that most people don't even think to look for such.

Sun transits getting lower, entering September

Event Date: September 1st
Time: 1:08(.31) PM


Brief

As we approach these last three weeks of summer, it is a time that we see the Sun move further towards the southern declinations as fast as we see all year.  When looking at the image below, featuring the Sun, celestial equator and ecliptic, we see a decrease in altitude for transit happening each day.  By looking left (east) of the Sun, the green ecliptic is seen coming towards the celestial equator and dipping below it.  As the Sun follows this path, it dips more than 11º during the last month of summer, and that same number for the first month following the September equinox.  I showed a similar scenario shortly after the March equinox, as the Sun spent the following 4 weeks becoming further north in declination, albeit slightly slower each day during that span.
  The image here shown here displays the Sun at transit.  The celestial guidelines mentioned, as well as the meridian, all show.

click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

   As the Sun gradually gets lower at transit, it of course, spends less time above the horizon,  By winter, especially the first few days, our star is only 29º above the horizon, or  just shy of 1/3rd the way between the it and zenith.  Right now, at about 8º north, the Sun transits just over 60º in altitude, or 2/3rds of the way between horizon and the sky,  Although transit altitude is based on latitude, one thing is for sure this month: the altitude will always be the same number of degrees for the celestial equator.  Therefore, for viewers at our global equator, the Sun transits at zenith at equinoxes.  For viewers between there and 23 1/2º north and south of the equator, they also have zenith transits on other days of the year, depending on their exact latitude.  For example, someone living at 11º north, somewhere in Central America, will have a zenith transit of the Sun around April 18-20st (depending on whether or not it is a leap year), and also around August 19-21st.

Mercury and Regulus low in east

Event Date: August 31st
Time: 6:15 AM


Brief

   Yesterday I talked about Regulus being close to Mercury, while this morning, they are slightly closer.  Regulus is much dimmer than Mercury, with the planet brightening gradually.  Since Mercury emerged from the Sun early this month, it has brightened in apparent magnitude by about 100 times, now at -1.3.  As for Regulus, it is about 1.6º from Mercury this morning, as image two shows in a 2º field.  Preceding that, is a showing of both rising in the east.

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

Since Mercury has started moving slightly further from the Sun each day for the last week post-perihelion, that means that it has also moved away from us slightly faster, and not brightening as fast as it was during the first 3+ weeks of the month.  Today and tomorrow, we will see it at nearly the same separation from Regulus, being very binocular friendly.  After Mercury separates from the star, Regulus becomes easier to see, rising four minutes earlier each day.  As it does, the Sun quickly starts to move towards the celestial equator over the next few weeks, meaning that we have more dark sky time to see Regulus each week.  The Sun rises about a minute and a half later on average each morning during September.  Mercury however, stabilizes in magnitude as it reaches superior conjunction, and will not be easily visible again for about two weeks following that.  Once it finally is, it will be victimized by the poor evening geometry of the western sky at this time of year.  By the time the geometry starts to improve slightly in mid-late October, Mercury will already be too dim and low to see easily.  Therefore, enjoy it bright now, while still just high enough in the east.  It rises a little less than 50 minutes before the Sun, with Regulus to follow about 7 minutes later.

Mercury, Venus, Jupiter, Sirius, Regulus, all rising

Event Date: August 30th
Time: 6:15 AM


Brief

   As Mercury approaches superior conjunction, the geometry of the eastern sky has been favorable enough to let us see it at a very bright magnitude, while still separated enough from the Sun.  The planet (mag -1.3) still rises a little more than 50 minutes before our star, and just slightly dimmer than our brightest star Sirius (-1.5) when seen with the eye.  To some viewers, the two will look the same brightness, although Mercury will not twinkle; more of that in the detailed section.  Before that, I will show Mercury, Sirius, Venus and Jupiter.  Notice how the triangle shape of Sirius, Venus and Jupiter continues to become more impressive as Venus pulls away from Jupiter more quickly each morning.

Detailed

Seen further south (right) of Mercury when looking at the image below is Sirius, much better placed for viewing pre-Sunrise, than it was at the beginning of the month in the glare of dawn.  While at that time, Sirius and the Sun only about a half-hour apart rising, Sirius now rises about two and a half hours earlier than the Sun.  During nautical twilight, observe it sparkle many colors as its light is refracted through the atmosphere.  The cycle of colors is quite fast, so try doing so with a telescope out of focus to notice the range of rainbow-like ones.
   Getting back to Mercury, as a review, it does not make its own light as Sirius does, but a big enough gibbous shape now to reflect alot of it from the Sun to our eyes.  Less than a week past perihelion, Mercury is a little closer to us than it would be at aphelion and therefore, the aforementioned Sirius-like magnification.  Jupiter, at about 70 minutes before transit, and Venus lower down, are seen much brighter in the sky.  Both are higher than Mercury, and rise before astronomical twilight.  As I mentioned with Mercury, Venus is getting help from the sky's geometry as well, rising over 3 1/2 hours after the Sun.  It is past greatest elongation, but far enough north of the Sun to be very well placed at this time of morning: a little more than 36º in altitude.
   Finally, look below Mercury in the image, at Regulus (mag. +1.3), barely visible in atmospheric pollution and Sun glare.  Mercury is being several times brighter, so let it guide us to the "Lion-star".

Mars further separates from Saturn and Spica

Event Date: August 29th
Time: 8:30 PM


Brief

   Saturn, Mars and Spica have changed triangular configurations over the last 4 weeks, while faster Mars has passed Saturn in prograde motion: west to east against the stars.  All three form a right-triangle this evening, with Saturn marking the 90º apex.  Mars will continue to pick up speed in prograde motion, with the triangle eventually flattening out enough that it becomes a curvy line, somewhat as an arc.
Shown below are the planets and star as described above.

click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

By the time that Saturn catches up with Mars again in about two years, they will be further east of Spica, within the boundaries of Libra.  The next encounters with Spica for all three will be during the years of 2040 and 2042.  This of course, is when Saturn returns to the star during its 29 1/2 year revolution, and Mars on the other side of the sky during the "gap" year of 2041.  The most impressive date for this time period happens September 8th of 2040.  Do you know why?  If not, yet you have astronomy software, jump ahead to that date and find out!

Moon waxing, and "going north"

Event Date: August 28th
Time: 11:10(.53) PM


Brief

   Several times when showing the Moon and its orbit, I have shown where the nodes are, and/or when it is ascending or descending towards a node.  This evening shortly before midnight, the Moon transits in northern Capricornus, as a big, waxing gibbous; it is just a couple days from becoming full and a bright target tonight until setting shortly before the break of dawn. 
   Here is our satellite shown with the celestial guidelines, altitude/azimuth grid, and its orbit.

click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

The ecliptic latitude is already +4º, meaning that the Moon is very close to the legs of Aquarius, where it will cross over tomorrow.  Aquarius is the only zodiacal constellation to clearly overlap another in celestial longitude, being Capricornus.  Not only is the Moon ascending in orbit, but it is also increasing quickly in declination over the next few days.  It is because of this, that we will see the Moon transiting higher each evening between now and when it reaches western Taurus.  It also means that for the minutes shortly after transit, the Moon will very slowly lose altitude since as it sets.  However, since it also gaining that declination, that slightly offsets the altitude loss.
   If viewing the Moon through a telescope during the next 3-4 hours as a true night-owl, watch to see if you can see it wax more, as the terminator also cuts across less of the Moon between now and full.  During the last hours of waxing, the change is very small and hardly noticeable even in a telescope.
  

Uranus goes non-zodiacal...briefly!

Event Date: August 27th
Time: 3:14(.16) AM


Brief

After spending the last two evenings talking about Neptune, I will hop forward towards the Sun by roughly a billion miles (give or take), and now talk about Uranus.  In the constellation of Cetus, for limited time, this is normally the time of Uranus' revolution that we see it in Pisces.  However, because of the planet's ecliptic latitude swinging it a bit south of the ecliptic, from our perspective, it is just barely within the boundary of the sea monster.  There will be some back and forth on this over the next several months, as Uranus' retrograde-then-prograde motion has it cross the boundary a few times.
   The image here shows Uranus at transit within the Cetus boundary lines, It comes back to Pisces late this year, via retrograde motion, then back to Cetus for about a month early next year via prograde motion.  Notice when looking closely, how near Uranus is to the border, and how the unevenness of them can have us understand the back and forth irregularly.

Detailed

At about 1.8 billion miles from the Sun, Uranus takes about 84 years to revolve, and as a result of being so much further from the Sun than us, has a retrograde period of about 5 months.  This is compared to only a little over 2 months to our nearest outer-neighbor, Mars, and a little more than Jupiter and Saturn and around the 4-month mark for each.  For Uranus, which covers about 30º of sky every 7 years (equivalent to about one zodiacal sign for that duration), it gives most of us fortunate enough to live long enough, to see it make a complete revolution during our lifetime.  Since most of us likely won't understand the planets' movements against the stars until we are between 10-20 years old, if not beyond that span, it means an even longer time to have to live to consciously track a full Uranus revolution.  If you are one of those who remember exactly where Uranus was in the sky when you were a young age, via binoculars or a telescope, hopefully you have followed it ever year since, to really have a good perspective of what planets do, and how they earn their name as "wandering stars"!
   This second image shows Uranus with a star field of 1º, or about 50x in magnification.  Just as the case with Neptune in Aquarius, Uranus has a dim star field in Cetus, with most of the sea monster's "brighter" stars further south and east (while many are not much brighter than Aquarius'.

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Mercury rivals Sirius in apparent magnitude

Event Date: August 26th
Time: 6:00 AM


Brief

   This is the best week to view Mercury before it gets too close to superior conjunction.  At magnitude -1.1 it is rising one hour, 12 minutes from the Sun.  Therefore with an unobstructed horizon, we have over 40 minutes of easy Mercury viewing between when it escapes atmospheric pollution and when the sky washes it out.  The evening sky's geometry at this time of day is nearing its best in about 6 weeks, yet until that time, good enough for watching Mercury brighten each morning.  Here it is seen just north of east, about 6º above the horizon and easily visible in this part of the sky.

Detailed

As Mercury brightens further this week, while still visible before disappearing in the Sun's glare, it begins to rival a bright star that I talked about earlier in the month: Canis Major's Sirius, at magnitude -1.5.  Mercury reaches this magnitude in a little over a week, although for the day or two before reaching the same, it will be close enough to matching Sirius that they will have similar brightnesses to our eye.  Of course, why Sirius twinkles like mad through atmospheric pollution, Mercury is reflecting our Sun's light and it comes back to us.  The second image shifts the sky further to the southeast for center-azimuth, showing Mercury and Sirius.  Of course, Venus and Jupiter are high above, making it a part of that sky quite bright full of solar system bodies and our brighest star in apparent magnitude, seen from Earth.

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Uranus goes "non-zodical"...briefly!

Event Date: August 25th
Time: 3:14(.16) AM


Brief

After spending the last two evenings talking about Neptune, I will hop forward towards the Sun by roughly a billion miles (give or take), and now talk about Uranus!  In the constellation of Cetus, for limited time, this is normally the time of Uranus' revolution that we see it in Pisces.  However, because of the planet's ecliptic latitude swinging it a bit south of our Sun's path, from our perspective Uranus is just barely within the boundary of the sea monster.  There will be some back and forth on this over the next several months, as Uranus' retrograde-then-prograde motion has it cross the boundary a few times.
   The image here shows Uranus at transit within the Cetus boundary lines, It comes back to Pisces late this year, via retrograde motion, then back to Cetus for about a month early next year via prograde motion.  Notice when looking closely, how near Uranus is to the border, and how the unevenness of them can have us understand the back and forth irregularly.

click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

   At about 1.8 billion miles from the Sun, Uranus takes about 84 years to revolve.  As a result of being so much further from the Sun than us, has a retrograde period of about 5 months.  This is compared to only a little over 2 months for our nearest outer-neighbor, Mars, and a little more than Jupiter and Saturn; around the 4-month mark for each.  For Uranus, which covers about 30º of sky every 7 years (equivalent to about one zodiacal sign for that duration), it gives many of us living long enough to see it make a complete revolution during our lifetime.  Since most of us likely won't understand the planets' movements against the stars until we are between 10-20 years old, it means an even longer time to have to live to consciously track a full Uranus revolution.  If you are one of those who remember exactly where Uranus was in the sky when you were a young age, via binoculars or a telescope, hopefully you have followed it ever year since, to really have a good perspective of what planets do.  By knowing such, we also can know why they earn their name as "wandering stars"!
   This second image shows Uranus with a star field of 1º, or about 50x in magnification.  Just as the case with Neptune in Aquarius, Uranus has a dim star field in Cetus, with most of the sea monsters "brighter" stars further south and east (while many are not much brighter than Aquarius'.

Neptune: star fields, and its moons

Event Date: August 24th

Time: 1:15(.22) AM


Brief

   Yesterday I showed Neptune on the rise.  Although at opposition this week, it is only slightly brighter than when near conjunction with the Sun.  While showing it rise in Aquarius, among the water bearer's dim stars, I also picked a time that even a powerful telescope would have to battle atmospheric pollution.  This time, I will show the planet at transit during the wee hours of the morning, when a powerful enough telescope can more easily pick up the methane-blue color.  The first shows a zoom-out of Neptune's position in the sky, with a decent altitude (41º), yet just barely good enough to be out of atmospheric pollution.

Detailed

   One other thing that I mentioned yesterday is that Neptune is near the star Iota (Aq)uarii: a 4th magnitude star that Neptune will get a little closer to over the next two months as it completes its retrograde motion.  Once it starts in prograde again, Neptune pulls a little further from the star each year.  As it does, spending the next decade-plus within the water-bearer's boundaries, it will pass by more stars, although very few matching the brightness of Iota Aq.
The second image is a 1º field (about 50x to show the stars surrounding the planet.  With Neptune about magnitude 8, the brightness of the other stars can be compared; those just barely bright enough to see are closer to 12-13th magnitude, while some are slightly brighter, between 5-7th magnitude.  Using Neptune as a guide, can you tell which stars bare brighter?
  Finally, I included a rare 3rd image, for which magnifying the planet to about 200x.  Although a smaller field, the planet may appear more disc-like instead of pinpoint-ish.  This magnification of 200 or more also reveals Neptune's largest--and therefore brightest--Moon Triton, which is nearly as dim as the dwarf planet Pluto, at 13th magnitude.  A telescope of 6" or larger can pick up stars and Moons at this dim magnitude on very clear, dark nights.  Out of Neptune's 8 Moons, only two are large enough to find with powerful telescopes (Nereid being the other yet extremely dim at 18th magnitude).  The voyager 2 mission discovered the other 6 back in the late 1980's during a close fly-by.  Unlike Triton also, for which those 6 other Moons have orbits smaller than, Nereid has the most eccentric orbit in the solar system, as, shown in that 3rd image with Triton's.

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

 

Neptune near star Iota Aquarii

Event Date: August 23rd
Time: 9:00 PM


Brief

   I haven't talked about Neptune much this summer, although this is a good time to resume the focus.  Today, the distant planet--over 2 billion miles away--is at opposition this evening; 180º separated from the Sun, which is of course the same as saying, maximum elongation.  Shown below is the planet within the boundaries of Aquarius, about as high above the horizon as the Sun is below it.  The stick figure of the water bearer shows, along with that of west-neighbor Capricornus where Neptune spent over a decade prior to its Aquarius stay.

click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

   About four minutes before the Sun sets, more-southern Neptune rises; this is normal, considering that the Sun is still north of the equator and takes a little longer to sink towards the horizon.  When oppositions happen close to the celestial  equator, as we will see with Uranus a few weeks from now, the time of rise and set for the planet and Sun respectively usually has less of a gap.  The reason for this, is because the declination of the Sun and planet are closer to being the same.  There are times at the equinoxes that a planet's ecliptic latitude is a few degrees north of south, as is often the case of Mars for its oppositions.  However, the "gas giants"--Jupiter through Neptune--have orbits that don't swing them quite as far as Mars.
   Getting back to Neptune here, look at the star labeled that can help us find it a little more easily: although only 4th magnitude, Iota Aquarii is 3.2º apart from Neptune.  Having moved from the eastern Capriocrnus stars seen nearby, we will rely on Aquarius' stars and fields for hopping to Neptune from other targets.  This isn't too easily with Aquarius' brightest stars being hard to see.  However, getting to know the star fields help, while Neptune's retrograde motion will bring it back towards Iota Aquarii by several arc-minutes over the next two months.

Arcturus above Saturn/Mars/Spica grouping

Event Date: August 22nd
Time: 8:30 PM

Brief

   Yesterday when the Moon was grouped with Mars, Saturn and Spica, I posed the question about a bright star seen above it in the sky a little further north; a line extending from it through Saturn lead almost the Moon's position.  Although the Moon has moved east of the grouping since then, we can still see the other three as a near-isosceles triangle; Spica and Saturn are a little closer together than Mars is with the ringed planet. 
   Here is Arcturus, seen high above Mars, Saturn and Spica.  The Moon, which is quickly "fattening" as a crescent, is seen to the small triangle's left.  Mars is the closest to the Moon, with Spica as the furthest (angularly).

click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

   Arcturus sets after the trio by about two hours, after being high in the sky during most daylight hours.  The star rose shortly after 10 AM, and while still far enough apart from the south-moving Sun, can be seen during daylight hours through a powerful telescope and the clearest of skies.  At magnitude -0.1, it transits high in the sky during the early evening.  Try to find it at about 7:30 PM local time with smaller telescopes if you know where to look; this is the time when the limiting magnitude of the sky starts to gradually decrease in value, letting us see the brightest of stars in the sky a little more easily.
   Getting back to the Mars/Saturn/Spica grouping, they are still able to fit in a binocular field of 6º, yet barely.  As mentioned yesterday, try a field of 7 or 8º to get them all in more easily.

Saturn, Mars, Spica, and waning Moon grouped

Event Date: August 21st
Time: 8:30 PM


Brief

   Back on the 17th, I mentioned revisiting the Mars/Saturn/Spica trio; as a teaser, that they would have company.  That is correct, and that company is the waxing crescent Moon: 23% illuminated.  The four make a lopsided diamond shape, which gives it a perhaps "symbolic" appearance, depending how one thinks of it.  Even more impressive, as was the case yesterday, the triangle of planets and Spica is near-isosceles in shape, with Saturn as the apex.  More about that and separation values are in the detailed section.  First, I will show the quartet of Spica and solar system bodies unlabeled during the first minutes of nautical twilight.  Spica is closest the the Moon's lit portion, Mars closer to its darker portion.  What is that star in line with Spica and the Moon higher up??  Find out tomorrow, yet try guessing first, based on its position at this time of evening and year.

Detailed

   Both Mars and Spica are 4.6º from Saturn, with the difference of separation just arc-seconds from being isosceles.  As the evening goes on, Mars moves slightly further from both, although not noticeably with the eyes.  Using binoculars, they all fit in a 5º field, although using a field of 7 or 8º will be easier to view all three center-fielded.  Also, this is the way to view the Moon with them.  The second image shows all four in the field, shown here. 

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

   A few numbered stars from the constellation of Virgo (unlabeled) show in the field, all about the same magnitude.  One or two dimmer stars are also just starting to become visible at this hour with this field.  As the sky grows darker, more stars come visible quickly.  Since when looking at stars and planets in Virgo means looking nearly perpendicular to our galactic plane, it means that we don't have alot of deep sky targets easily visible to look at; mainly distant galaxies which are washed out by twilight and obstructed by atmospheric pollution.  When we start to get Virgo high in the morning sky late this fall, we will have a better chance to see some of those galaxies more easily with powerful telescopes. 
  

planets and stars: close and further separated

Event Date: August 20th
Time: 5:30 AM


Brief

There are two things to look at this morning, in the eastern sky before Sunup: Mercury, at about its best apparition of the year for the morning sky, has now passed by Asellus Australis, east of it.  The two are still visible in a telescope together, although a wider field is required to see them together.  As the mornings pass, Mercury separates itself further from the star, reaching superior conjunction [with the Sun] in September.
   Also, last week I mentioned the "other" triangle rising in the east at this time of year, with Jupiter, Venus and Sirius marking its points.  As Venus separates further from Jupiter, the triangle is taking shape nicely.  Venus is 29º from Jupiter and about 37º from Sirius.  Can you predict which day that it will become isosceles, with Venus as the apex?  I will reveal the answer in early September shortly before it happens.
   Both of the mentioned viewings are shown zoomed out in the following images, while the second image shows where the Vega/Deneb/Altair triangle is at the same time, about an hour before Sunrise.

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

  Notice with image two, that Altair is 6 minutes from setting, very low to the horizon.  Although not visible except from the highest of elevations, with optical aid needed to try to see it through thick atmospheric pollution, we can still see Altair through most of the night; that gives us about 9 hours to do so and therefore, the entire triangle high in the sky shortly after Sunset.  It is at this time of year that these three stars are seen at or near their highest during mid-evening hours, and the asterism dominates that section of the sky.  Tomorrow, I will do a transit update of the triangle, while remember, that the Venus/Jupiter/Sirius trio continues to take shape for the next 2-4 weeks, depending on exactly what separation patterns you are looking for.

more on Mercury and Asellus Australis: closer

Event Date: August 19th
Time: 5:30 AM


Brief

   Yesterday, I showed Mercury near the star Asellus Australis.  This morning, the planet appears slightly brighter and closer to the star: a separation of 22 arc-minutes.  At apparent magnitude -0.4, we can magnify the rising pair to over 100x with a field large enough to fit them: 1/2º, although a full degree of field makes them appear more centered to the eye, not having to look close to the circumference of the field.
   The first image shows it and the star zoomed out, while the second image shows a zoom in of a 1/2º field to see the pair more easily at a magnification of slightly over 100.  If you want to magnify it more, you can; just keep in mind that since it is still within atmospheric pollution, that such will be more evident when viewing it, and Mercury may not appear as steady. 

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

Use a telescope of at least 4", allowing for a magnification boost.  There is no need to have a telescope so big that it takes awhile to set up; Mercury is for the most part, featureless, looking like a dull version of our own Moon.  Of course, being much further away than our Satellite, at about 92 million miles right now from us (slightly under one a.u., being just past greatest elongation) Mercury is hundreds of times further than our Moon at its mean distance.
   Shortly after 10 AM, which is dawn for viewers in the far east, the two are at their closest at slightly 15 arc-minutes.  Viewers in Australia and New Zealand can see this too, although the geometry of their morning sky is much worse than ours at this time of year, and they will have to look more towards the horizon.  However, they don't have to be as concerned about morning twilight lasting long, being late winter down there.  Although we miss the closest encounter, we still get to see Mercury pass by several stars--some brighter than others--during this fine, late summer apparition.  Look forward to Mercury continuously growing brighter between now and when we start to lose it to the glare of the Sun shortly before superior conjunction next month.
  

Mercury approaching [star] Asellus Australis

Event Date: August 18th
Time: 5:30 AM


Brief

   Keep a good eye on Mercury the next two mornings, as it brightens faster and reaches dichotomy.  It is approaching a star seen to its east this morning, moving towards it in prograde motion.  At 1 1/2º apart is Asellus Australis (Delta Cancri): a double star within the crab's boundaries at magnitude 3.9.  Since skies are dark enough now when Mercury and the star get slightly out of atmospheric pollution, we can see them easily as a pair in binoculars or in a wide-field telescope.  If skies are clear enough and we wait long enough for them to get higher, we can see them both with the eye.  Seeing the star this way is challenging, and especially if waiting too long and the Sun's glare gets in the way.
   Image number one is the zoom-out, and the second a zoom-in with a field of 2º.

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

   Tomorrow when I revisit this pair, they will be quite a sight with a high magnification: Mercury will be just past dichotomy, just starting a waxing gibbous phase, and the star will be very close to it.  Not often do we see Mercury so close to an unaided-eye magnitude star, and especially when Mercury is at such a good magnitude (-0.3 this morning and a little better than -0.4 tomorrow).  With the geometry of the eastern morning sky improving fast between now and early October, it remains good throughout early December when we have our final Mercury morning apparition of the year.  Between now and then, we have a poor evening apparition of Mercury, which will make it hard to see it near stars; it will be south of the Sun for that one, while north of the Sun right now for this one.  Be ready for tomorrow and have a telescope with a low-focal length eyepiece ready!  Even using a telescope with a long-focal length eyepiece and/or low f-ratio telescope, you can notice a deep sky attraction near the pair; I will reveal that tomorrow as well.

Mars, Saturn & Spica within 5º

Event Date: August 17th
Time: 8:30 PM


Brief

The Mars/Saturn/Spica configuration has changed slightly each day, although looking very triangle-ish at two different times: a little over a week ago, and for a few days this week. 
   Before going into separation values, let's look at a zoom-out and zoom in of them, with the second image putting them in a 7º field.  As I mentioned a few entries ago, this makes it hard to see the rings of Saturn when zoomed in just a small amount.  However, leave that for more powerful telescopes, and enjoy the triangle for now!

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

Mars' prograde motion, and of course that being much faster than Saturn, has had us see it pass between the other two: forming a small line with the them on the 13th and 14th (straighter as seen from the other side of the world during their evening hours).  Between now and the 20th, the triangle stays very near isosceles form, and close to equilateral on one or two evenings of the span.  The three fit this evening in a field of 5º, although using a 7 or 8º field is better for keeping them all easier to see and further from the circumference of the field.
   Mars is 3º 01' from Spica, and just 4 arc-minutes further from Saturn, at 3º 05'.  Meanwhile, Saturn and Spica are just slightly more than 4 1/2º apart; hence my original mention of the 5º field if one still decides to use that.  Binoculars can give this if powerful enough, although medium-power binoculars are ideal to get all three into the field.
   Tomorrow, the triangle is not quite as isosceles, so I will find something else to look at.  I will revist the triangle on the 21st: for that day, they have "company".  Can you figure out what??

Mercury at greatest elongation: morning sky

Event Date: August 16th
Time: 8:30 PM


Brief

   Mercury is well placed now in the east before Sunrise, at greatest western elongation.  Along with Venus, Jupiter and Sirius, which I showed yesterday slowly forming another triangle (to go with the Vega/Deneb/Altair shape in the west at this hour), I label Mercury below.  Lower to the horizon, is also a very old crescent Moon, which may be just barely visible before Sunrise, as a sliver.
The orbits for the planets also show with the ecliptic.
   The second image shows Mercury (mag 0.0) approaching dichotomy, zoomed in to about magnification 200x.  Currently, Mercury is at 42% illuminated, reaching the halfway point on the 18th. 

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

Mercury is only 18.7º separated from the Sun, as it is only about a week and a half from perihelion.  Therefore, as it loops back behind the Sun, viewed from us on Earth, it will be a little closer than average to us.  Therefore, as it continues to wax, the apparent magnitude of Mercury will quickly increase.  For the next week, with the geometry of the morning eastern sky still improving, Mercury spends the next couple of days rising 90 minutes before the Sun.  This is not the greatest rise-gap that we see with the two, as they can sometimes be 100 or so minutes apart when the geometry is right and Mercury is separated enough from the Sun; that won't happen this time.  However, the declination gap between the two is good right now, meaning that for several minutes of darkness, brightening Mercury will be easy to see for well over half an hour low to the horizon.

two summer triangles: one rising, one setting

Event Date: August 15th
Time: 5:30 AM


Brief

   Earlier this month, I kiddingly mentioned a "second summer triangle" rising in the eastern morning sky; that being, as our familiar one consisting of the stars Vega, Deneb and Altair, sets in the west-northwest.  Venus, Jupiter and Sirius make up the second one that I teased about, and not starting to slowly reach a more recognizable shape.
Here is a reminder of where both triangle shapes can be seen shortly before Sunset.  Altair is on its way down below the horizon before the Sun comes up, and we will start to see the entire triangle for less minutes each day between now and when we finally lose Altair to the horizon late this year before darkness.  First the real, then the Venus/Jupiter/Sirius (V/J/S) one, shown below.

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

Unlike the Vega/Deneb/Altair (V/D/A) trio, the V/J/S triangle has its stars change configuration slightly each morning.  Why?  Simple.  Just remember the definition of the word planet: wandering star.  Venus is picking up prograde speed against the stars each morning as it moves further from us in its orbit, while Jupiter is slowing down in prograde, approaching stationary in upcoming weeks.  Sirius is the only "fixed" star of course, and as for the other triangle, all three of those stay fixed, disregarding proper motion.  Of course, Altair also dips into heavy atmospheric pollution before the sky starts to get lighter, making it harder to see.  Since Venus and Jupiter rise earlier by about four minutes earlier each day, as does Sirius, we see V/J/S higher in the dawn sky each day, and V/D/A lower each day, setting earlier.   Although the software does not let me draw lines between the planets and Sirius, the shape can be seen even if I left out the labels.  As Venus separates itself further from Jupiter, the shape of V/J/S will soon resemble that of the V/D/A.  Both are seen with all three stars each above the horizon at the same time for a limited number of days between now and later in the year; eventually, Venus comes close enough to the Sun again before superior conjunction, that by the time it rises, Altair is already below the horizon.  By then also, Venus is separated enough from Jupiter and Sirius that the three don't even form a triangle anymore; instead, more of a large arc-shape that we do not see until Venus rises.

Mars, Saturn and Spica near closest separations

Event Date: August 14th
Time: 8:30 PM


Brief

Mars, Saturn and Spica now barely fit within a 5º field, although a 6 or 7º one is ideal to view all three of them centered closely.  I reviewed the trio earlier this month, when they were seen in an 8º field.  Through a 5º one, the magnification is enough that Saturn's rings may be just barely visible--the "extensions" of them on either side of the disc, although more magnification is required to see them clearly.  Here are the planets and star featured below, with a zoom-out and a 7º zoom-in.  Since the latter is a small magnification, the software doesn't show Saturn's rings at all.

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

Mars is about 1.8º from Spica and 2.7º from Saturn; the closest that the Mars and Saturn are to each other this time in angular measurements.  Spica and Saturn are 4.5º apart.  The trio was tightest back on August 8th, when the largest separation of any of the three --Saturn and Spica in this case-- was just under 4.5º.  Since then, Mars has closed in on both, with the closest separation between it and Spica happening yesterday; about 6 arc-minutes closer than yesterday. 
   Mars will distance itself from Spica and Saturn as the days pass, and eventually, Saturn will follow suite, leaving Spica isolated.  As a result of retrograde next spring, Saturn will retreat towards Spica, but the closest encounter will not be as close as that earlier this year.

Perseus' figure, illustration, and meteor shower

Event Date: August 13th
Time: 1:00 AM


Brief

   I talked about the constellation of Perseus during the late spring and early summer, when it was rising not long before Sunrise.  Now, the entire constellation can be seen from our spot on the globe just after midnight, and high enough as seen at the time above.  As shown in the image below, it is seen in the foreground of the Milky Way band, which can be seen well under a dark sky.  Even without the darkest of skies, the 2nd and 3rd magnitude stars that make up Perseus' stick figure, makes it somewhat easy to see. 

Detailed

   The most western of the stars which rise first, are that of the hero's sword.  What looks like two "legs" sticking down further south and east, have one make up just that, while the other makes up his arm, hand and sack being held with ugly Medusa's head, after she turned herself to stone.
See below, magnified here, as I also included Perseus' classical illustration.

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

*Notice the labeled Pleiades towards his left foot.

Also, at this time of August each year, especially under a moonless sky, we have the famous Perseid meteor shower.  They are usually easiest to when the constellation is high enough up, as the radiant is very close to the stick figure.  Meteor showers, as viewed from Earth, are when we pass through the debris of comets.  This debris stays around for years, decades, if not centuries.  However, sometimes we have more meteors seen than other years, disregarding the moon's phase.  The best time to view them this year will be the 11th and 12th, although during non-leap years, the 13th is usually among the dates instead of the 11th. 
To learn more about the Perseids and other meteor showers, read here:
http://earthsky.org/tonight/wheres-the-radiant-point-for-the-perseids
Earthsky, I should admit, inspired me to start doing astronomy journals years ago, and now having them in blog form years after starting to learn how to journal my and others' findings.

Jupiter, Moon and Venus in-line

Event Date: August 12th
Time: 5:45 AM


Brief

   This is the third and last of this series featuring the three brightest objects in the sky this month when the Sun is below the horizon: in line, Jupiter, the waning crescent Moon and Venus. with the latter very close to greatest eastern elongation.  The image, for which showed the stars of the Winter Circle yesterday, has all those stars still showing, but not labeled this time; I want to focus on the solar system bodies instead.  With the aforementioned in line, I will also show their orbits.  Looking further east, we see the different inclinations of the three orbits, with most-distant Jupiter having its following along the ecliptic closer than inner-planet Venus and the Moon.

click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

    At 45.7º this isn't the furthest separated that we see Venus from the Sun, as it can be as far as between 47-48º.  The variance is partly because sometimes we see Venus closer to aphelion or perihelion, although sometimes it depends on where we see it related to the Sun from our position.  More impressively, as the geometry of the eastern sky improves over the next couple of months; the declination gap between the Sun and Venus grows, as Venus slowly loses declination towards the equator while the Sun moves towards south at its fastest-- particularly the days surrounding the September equinox.  Venus is also close to dichotomy, at 50% illuminated.  The more it waxes, unfortunately the more it seems to shrink in angular size.  Although this hardly affects its apparent magnitude right now, we should remember that as Venus gets close to superior conjunction in about 5 months, it will be seen much smaller in a telescope.  By the time it reaches conjunction, it is about 1/6 the angular size that it was at inferior conjunction (as we saw it during the transit of the Sun), while being about 6 times further from us than it was during that week.

planets, the Moon, and winter circle stars

Event Date: August 11th
Time: 6:00 AM


Brief

  There are two things to observe looking east this morning, and even over the course of the next few weeks: The Winter Circle, consisting of the stars labeled below in small red, are accompanied by three planets and the waning crescent Moon.  Mercury (mag +1.0), which is brightening slowly each day as it reaches one of its better greatest elongations of the year, is low to the horizon; Venus (-4.4) is higher up, dominating the sky in brightness; Jupiter (-2.2) is highest, with the Moon only 3º away from it.  Here they are shown with the planets and Moon's labels in darker, bolder red.

click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

   Eventually, Mercury will leave the scene, as (1) the circle is seen higher in the east each week, and the (usually) elusive planet sinks back towards the Sun.  Venus will stay high with an excellent apparition for a few months, and then start to slowly sink back to the horizon as it becomes further south of the Sun this winter.  Jupiter will continue to become closer to transit during dawn, and stay within the circle as it moves more slowly than the inner planets.  Jupiter is still in prograde motion, yet will reach stationary and retrograde this fall.  As a result, it will come back towards the Hyades, Aldebaran, and other stars within Taurus.  By this time, the Winter Circle becomes visible in the east near midnight, and later in the year, at the time of early evening shortly after dark.
  

three planets and the Moon, all separated

Event Date: August 10th
Time: 5:45 AM


Brief

   We have an interesting line-up of solar system bodies this morning, with Mercury still part of the focus of it.  Starting with that planet closest to the horizon, Venus, Jupiter and the Moon are seen with different separations, looking up high.  Just as it did about a month ago, the Moon is closing in on Jupiter and will pass very closely to it.  As a result of Jupiter slightly changing in declination and the Moon's slight node precession since last month, the Moon and Jupiter will have a very impressive pairing; especially as seen from some other parts of the world when they see the two above the horizon after we do. 
      Here is the alignment of the bodies together, with no orbits showing.

Detailed

   As seen with the four lined up, we get an idea of how our planets--and sometimes the Moon--are all very close to the ecliptic plane.  Looking below, I included all four again with the ecliptic and celestial equator; the latter included to show the declination differences between them.  The Moon is seen north of the ecliptic although approaching descending node.  The planets are currently all viewed north of the ecliptic.  The change in ecliptic latitude varies, depending on how close--or far--we are from a planet in our own orbit.

click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

   Since the Moon moves about an average of one diameter per hour, looking at it when high enough to see here, can help us predict almost the exact hour when it will be closest in separation to much slower-moving Jupiter.  Of course, the Moon is affected much more by our gravity, being our satellite, whereas Jupiter is pulled much more strongly by the Sun,

Mercury's brightness compared to "dog" stars

Event Date: August 9th
Time: 5:45 AM


Brief
     
Mercury is now visible to the eye alone, as it has brightened quickly.  When we saw it emerging from the Sun's glare in retrograde about a week ago, we saw it only as a thin crescent.  Despite the good geometry of the eastern sky at this time of year, it wasn't enough light reflecting back to our eyes, from the small planet.  Now as Mercury waxes, currently at 18% illuminated, that has helped see it better.  Keep it mind that since Mercury is so much smaller than Venus and its orbit doesn't bring us as close to it during inferior conjunction, it brightens and dims quickly, for waxing and waning respectively.  Here it is shown in orbit about 40 minutes before Sunrise.

Detailed

    Mercury rises 70 minutes before the Sun this morning.  Although the upcoming greatest elongation is one of which Mercury doesn't appear to separate from the Sun much, the declination gap between the two is slowly growing.  Therefore, with Mercury separating from the Sun and a bigger rise time-gap each morning in compared to the Sun's, the sky is darker to see Mercury more easily each evening until it gets too close to superior conjunction in early September.  A small number of days before then, the Sun is moving south towards the celestial equator at almost its fastest of the year, making still-brightening Mercury a good target for morning viewing.  It will not get as bright as Jupiter high above it, and Venus (both unlabeled) between the two being even brighter.  However, looking on the other side of east towards Canis Major a bit south of that is, Sirius (-1.5) is dimmer than Jupiter, and will be rivaled by Mercury in early September shortly before superior conjunction lower towards the horizon.  Whereas Sirius' light will refract through the atmosphere, making its own light, Mercury's reflecting of light will cause it to look still, without a fierce twinkle of many colors as Sirius will have for some minutes during twilight.  As the second image shows, shifted more towards the southeast, we see Sirius now low towards the horizon. several minutes before the Sun comes up.
Much dimmer Procyon, the "brightest" star of [little dog] Canis Minor, is seen between Mercury and Sirius.  I will get more into Canis Minor as the season progresses.  However, if you remember my Winter Circle entries from the late winter and early spring when it was high enough to see in the west, I mentioned the Procyon then.

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

more on Venus/Chi 1&2 Orionis, 64 Orionis

Event Date: August 8th
Time: 6:00 AM


Brief

Yesterday, I showed Venus exactly separated between Orion's Chi stars: 1 and 2.  This, after Venus was close to Chi1 on the 6th.  Today, after passing from 1 to 2, Venus and Chi2 are a little less than 1/2º apart as seen during morning twilight.  Considering that the stars make up the top of Orion's club, Venus has acted as a special "jewel" on the club, enhancing its power as a weapon.     

Detailed

Venus will leave the club-(Chi Orionis) stars after this for several months, as it continues to pick up speed in prograde motion, seen from Earth.  The next time that Venus is near the stars will be in about 10 months: early June.  As a result of how we view it in orbit, at a different perspective, we will not see Venus as close to Orion's club-top.  However, as an evening star at that time,  We will still see Venus bright and bold.
   As for Venus' position against the stars, look at these two images below: the first is similar to yesterday's second, yet now showing Venus closer to Chi2.  The time also shows them slightly later in the morning, and higher.  The second image shows a further zoom-in of Chi2, Venus and another star which Venus gets close to occulting as seen in the far east before Sunrise.  That star, is 5th magnitude 64 Orionis.  As seen at the time above from our location, the two are 7 arc-minutes apart.  A few hours later, the two are less than 2 arc-minutes apart, yet too high and with a bright sky to see them from here.

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.