Jupiter and Pleiades near each other

Event Date: June 9th
Time: 5:00 AM

Brief

  Jupiter rises a little over an hour before the Sun this week, and is bright enough to be visible for a short while before the Sun washes the sky out.  If not with eyes alone, try with binoculars.  Normally when the planet is further from the Sun in separation, it has a red-orange look to it when low to the horizon.  Since it is rising a more north of east than last year and much more so than two years ago, we see it make the "curving-rise" motion as seen from our latitude.  See image one for the celestial graph reminding this.

Detailed

   Back when Jupiter was seen rising during the second half of 2010 in Pisces, a part of the sky where the Sun is near the time of the vernal equinox, Jupiter was rising at more of a right angle with the horizon.  As the first image above shows, Jupiter at declination 19º makes that upwards curve when rising, and downwards when setting.  We are not seeing it set yet since it does so in the early evening before the Sun.
   Look near Jupiter by about 5º to its left, which is a little more north: the Pleiades star cluster, which dominated the fall and winter skies among deep sky targets, makes a morning return.  It may be just dark enough to see it before Sunrise.  Try looking again in about a week when it rises about 27 minutes earlier than it does this evening before the Sun.  Being more northeast than Jupiter at this time it rises about that same number of minutes before Jupiter.  The second image shows both in a binocular field of 7º.

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

Mars "gaining" on Saturn

Event Date: June 8th
Time: 9:00 PM

Brief

   Let's take a peak at Mars, which is now starting to pick up speed faster in pro-grade motion.  After spending several weeks in Leo, which is where we saw it during its opposition, it is approaching the Virgo border, crossing it later this month.  We will take a look at it and Saturn here partly zoomed in, with the latter currently in Virgo.  Since I am showing the celestial paths with the increment markers for every 10 days, the 25% zoom in (75º viewing field) lets us see the markers a little more clearly for slower moving Saturn, along with Mars' path for when it was resuming its pro-grade motion not long ago.

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

Detailed

   While in retrograde during that time for a little over two months, that movement was sandwiched by the prograde motion, as we see with our planets.  While still in Leo, Mars will eventually start catching up with Saturn more quickly, 35º east of it this evening.  The ringed attraction remains in retrograde for another two and a half weeks.  During the time after that, as Saturn goes stationary and then very slowly in pro-grade, Mars will gain on it.  Even as Saturn picks up a bit of movement west to east, Mars is so much closer to us and the Sun than it, that before Summer is over, we will have a conjunction of the two planets.  Mars continues to dim, and is currently only +0.6.  Saturn is slightly brighter right now, yet not noticeably.  By the time that the conjunction happens, Mars will further dim closer to the +1.0 mark, while Saturn dims more slowly.

Mercury emerging east of Sun

Event Date: June 7th
Time: 9:00 PM

Brief

   Despite the Sun setting about as late as it will all year, and civil twilight nearly at its maximum length for the year, Mercury is separated enough from the Sun to be visible to the eye alone for a very short while.  At magnitude -1.0 and starting to dim a little faster each day, these next 7-10 days are the most ideal for trying to find Mercury quickly.  Here is Mercury with orbit and celestial guidelines to show its positioning. 

Detailed

   Notice that Mercury sets not far from the northwest azimuth mark (315º).  Right now, it is far enough north on both the celestial dome--and of the Sun for a small amount of time--to spend enough time above the horizon after Sunset.  At a little over 25º thanks to a good ecliptic latitude, Mercury reaches its best declination tomorrow evening, just slightly more so than now.  The elusive planet sets 67 minutes after the Sun this evening, although still a little over three weeks until greatest elongation.  By then, it will be nearly at aphelion and already dimmer than magnitude 0.  As mentioned, definitely try to see it over these next few days with the eye alone why still bright enough.  The maximum Sunset gap, which I will mention more about in a couple of weeks when it happens, will still be a good time to see it, although we will have better success with binoculars by then.
   This second image shows Mercury as a waning gibbous. 

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

It is 85% illuminated and an angular size of 5.5 arc-seconds.  As a result of being low in the sky towards atmospheric pollution and that small, I will use a field of about 11 arc-minutes (approximately 1/6º).  This is a magnification of about 280x, which is ideal in a telescope of 6" or larger.  Since Mercury's features--or lack thereof--cannot be seen from Earth, it is okay to use a telescope of low resolution, as opposed to one such as 8 or 10".

Venus and Sun post-transit

Event Date: June 6th

Time: 5:45 AM


Brief

 
Did you have a chance to view the Venus transit yesterday, weather permitting?   As mentioned yesterday, the next one will not happen until December of 2117.
   If we continue our attention on Venus, we can now look forward to it emerging from the Sun in the morning sky, moving at its fastest in retrograde, and seen west of our star in a few weeks.  As I place Venus' orbit in the image below, it represents the improving geometry of the eastern morning sky this month. 

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

Detailed

  Between now and October, not only does Venus separate itself quickly from the Sun, the geometry of the eastern half of the sky dramatically improves.  Not long after the summer solstice which happens in a couple of weeks, Venus catches up with the Sun in northern declination.  It will be after this time when the Sun continues to move south towards the September equinox, that Venus does so much more slowly.  As a result, the dates of/near greatest elongation will give another fine apparition of Venus; not quite as good as we saw it much of the spring east of the Sun in the evening, yet still excellent.  Later fall and winter months will mean that Venus will sink more and more quickly towards the horizon and Sun, as it approaches superior conjunction early next year.  During the start of 2013, when the Sun starts to move north again faster than Venus, we lose the planet from good view and altitude.  With all that said, the best months to look for Venus will be those of the first half of its time west of the Sun.
The cycle will be in reverse compared to the time in the evening sky: greatest brilliancy in a little over a month, followed by greatest elongation not long after.

Venus transit: ingress and deepest

Event Date: June 5th
Time: 3:07/6:27 PM*

Brief

   Today's journal will be the most special that I ever do: the transit of Venus!  The date and time above represents when it is seen from our location at (rounded) 38º N, 122º W.  For this event, there is not too much need to be as precise as I normally am with coordinates; the data I retrieve from websites will have cities listed as opposed to exact locations.  Fortunately however, the Starry Night software lets a person view the transit from any coordinate point on Earth *where it is visible.  Therefore, the hundreds (or thousands?) viewing from Chabot Space and Science Center including me, will see the times for ingress and deepest transit.
   There is one other reason that this journal is special as a result of featuring the Venus transit: it will be the only one that I ever view (safely!) during my lifetime; the next one does not happen for another 105 1/2 years.

Detailed

First before magnifying silhouette-Venus and the Sun, I will show a zoomed out image for when the transit's ingress begins:

The first thing that you may notice is that for Venus' orbit, we are looking directly edge-on towards the plane of it.  Naturally, this has to be the case, as Venus is also near its descending node (with the ecliptic).  Just as I have mentioned several times with the Moon's orbit and nodes, Venus' transit of the Sun is similar to the concept as a total eclipse of the Sun: it happens when we see Venus' disc completely dark, facing away from the Sun, the way that the Moon must be in "new" phase for a solar eclipse.  Unlike the Moon however, there is no "precession of nodes" for Venus or the other planets.  Therefore, the only times that a Venus transit is possible is during the months of June and December.  Since for so many other years we see Venus at a phase other than "new" during these months, that is what makes the transits as rare as they are.  From Sky and Telescope's link here, http://www.skyandtelescope.com/observing/highlights/Transit-of-Venus-February-2012-134332798.html I include the following:

<<a transit of Venus, happens only four times every 243 years. However, the spacing between each occurrence is very uneven: it's 121½ years, then 8 years, then 105½ years, then 8 years again. The last transit occurred in June 2004 — and after this June's event there won't be another until December 2117.>>

The second image is a zoom-in, this time featuring the deepest transit, and the field of view is 1/4º.  Notice that Venus--just slightly less than 1 arc-minute in angular size--has a disc size that is big enough to see the planet's (current) dark-side easily across the Sun.  I darkened the image to night-mode to make both the Sun and Venus more visible.  Remember that a transit is the only way to see Venus during inferior conjunction; for any other time, it is just passing east or west of the Sun, in blinding glare.  Once again, remember to use a recommended safety filter when viewing the transit!

   *NOTE: most websites that you many come across will show eastern or universal time for the beginning, middle and end of the transit.  Translate accordingly to your own, if you are somewhere else in the world where it is visible.

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

Full moon setting south of west

Event Date: June 4th
Time: 4:12 AM


Brief

   Yesterday I was showing the Moon rising and how it had passed ascending node earlier in the day.
Now, less than 9 hours later, I show it at the crest of fullness, shortly before setting.  This duration between entries also reminds what I said yesterday about (near-)full moons only above the horizon for between 9-10 hours above the horizon when viewed from our latitude; such being the case during late spring and early Summer months.  Look at where the Moon is near the ecliptic in relation to the celestial equator, being several degrees south [of the equator]. 

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

Detailed

   Look to the far left of the image, where the Moon's orbit is shown a few degrees north of the ecliptic.  Yesterday while the Moon was shown on the rise, I showed the orbit south of the ecliptic instead.  The way we see the orbit for today's entry at that left side, it shows something else: as the Moon moves to the part of the sky where the Sun is during winter months, its orbit will give it that slight extra "boost" north.  This cycle of north and south of the ecliptic happens about once a revolution for the Moon.  Since its sidereal period of 27 days, 7+ hours puts it at each phase a little further west than the cycle before, that is why in June we see it as full phase well south of the celestial equator; while in December, we see it north of the equator.  Of course, this is partly because of the Moon's movement around us, but also because of our revolution around the Sun.  The full Moon is at opposition with our star, putting it about 6 months before or after the Sun's position in the sky.  Viewed above, we see the Moon slightly west of the galactic center near Sagittarius left of it.  With the Sun located here in early December; the labeling along the ecliptic reminds us of this also, shown in the image.

Near-full moon rising south of east

Event Date: June 3rd
Time: 8:30 PM

Brief

   Normally at this time of year, the Moon does not get very high when full; it reaches altitudes that a late-fall or early winter Sun does, depending on where the Moon's orbit places it relative to the ecliptic.   As shown in the image, the Moon is just hours past (east) of ascending node.  When this node is at this longitude of the ecliptic, not far from where the Sun is for the December solstice, it means that while transiting low, the Moon quickly starts gaining transit altitude as seen from our hemisphere.  Over the next 5-6 days, as it also starts to move in the part of the sky that the Sun does during our winter months, its orbit speeds up the process of it moving close to the equator.  Take a look here first, seeing it on the rise just as the Sun goes down.  Since the Moon isn't quite full yet at the time of its rise 32 minutes earlier, it slowly moves higher while the Sun is still barely above the horizon.

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

Detailed

   Although I do not show the just-set Sun above, or the Moon when it just starts rising about 30 minutes earlier, it is enough hours before the crest of fullness that both are seen above the horizon for just minutes.  Since the Moon rises south of east and the Sun sets at almost its furthest north of west at this time of year, it means that we see the Moon for only a small number of hours.  Normally a full Moon within the few weeks of the June solstice only spends 9 1/2-10 hours above the horizon as seen from mid-northern latitudes.  Once again, the exact amount of time isn't based on our latitude alone, but the ecliptic latitude of the Moon.  Look again above, and this time to the right: when the Moon was about 90º west of where it is now about a week ago, it was almost 5 1/2º south of the ecliptic.  If you think about it, with the movement of the Moon north and south of the equator and ecliptic, there are two times [per ecliptic cycle] that it rarely gains or loses declination at all.  If you have an equatorial telescope which only tracks in right ascension, this means less "dec-tweaking"* for when the Moon moves north or south during a long time of viewing it.
 
*Many telescopes use this to keep the Moon centered north/south, and doesn't require much moving, yet very handy to have!