Event Date: May 12th
Time: 12:20(.41) AM/8:00 PM
Brief
I briefly mentioned Canis Venatici yesterday, as the "parent" constellation of large globular cluster M3. (C)or (C)oroli, which I introduced yesterday as well, is nearby M3 at magnitude 2.8. It is a key star to use along with Arcturus, for easily finding the cluster. At 13.8ª away, while we imagine a line straight from CC to Arcturus in Boötes, M3 is almost directly in line, at just short of 12º from Arcturus. Take a look at this image for when the stars are almost identical in altitude, to see what I mean. From our latitude, this happens for the two while Arcturus is shortly past transit by 17 minutes, and 38º declination CC is a little more than one and a half hour past transit.
Time: 12:20(.41) AM/8:00 PM
Brief
I briefly mentioned Canis Venatici yesterday, as the "parent" constellation of large globular cluster M3. (C)or (C)oroli, which I introduced yesterday as well, is nearby M3 at magnitude 2.8. It is a key star to use along with Arcturus, for easily finding the cluster. At 13.8ª away, while we imagine a line straight from CC to Arcturus in Boötes, M3 is almost directly in line, at just short of 12º from Arcturus. Take a look at this image for when the stars are almost identical in altitude, to see what I mean. From our latitude, this happens for the two while Arcturus is shortly past transit by 17 minutes, and 38º declination CC is a little more than one and a half hour past transit.
Detailed
The way wee see the three celestial bodies above is the way they are at this hour for our location. However. if our latitude was different, especially in the southern hemisphere, we may see them in line only very low to the horizon while rising instead of setting at some latitudes. Remember that all bodies rotate around the north or south axis, as opposed to east and west azimuth coordinates at the horizon. As an example, sticking to our horizon, lets forward from just after midnight to early this evening, when the three are rising. Look at the altitude difference: declination stays fixed (disregarding precession and proper motion for the stars) which has us see the bodies at different configurations with each other. The stars are more similar in azimuth below than they are in altitude, seen below!
The way wee see the three celestial bodies above is the way they are at this hour for our location. However. if our latitude was different, especially in the southern hemisphere, we may see them in line only very low to the horizon while rising instead of setting at some latitudes. Remember that all bodies rotate around the north or south axis, as opposed to east and west azimuth coordinates at the horizon. As an example, sticking to our horizon, lets forward from just after midnight to early this evening, when the three are rising. Look at the altitude difference: declination stays fixed (disregarding precession and proper motion for the stars) which has us see the bodies at different configurations with each other. The stars are more similar in azimuth below than they are in altitude, seen below!
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| click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp. |
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