Event Date: May 11th
Time: 11:29(.45) PM
Brief
Springtime is the best season to view the globular cluster M3, which transits high in the sky and near one of our brightest stars in apparent magnitude. With the zoomed-out image shown here first, we see the location of the cluster, at 28º north and therefore at our latitude, seen at 80º in altitude. It is the first deep sky object discovered by Messier, while the first two that he categorized (a nebula and another cluster in Taurus and Aquarius respectively) were discovered by others earlier. I will talk more about those in upcoming months, when they become visible during the summer mornings.
Looking in the same part of the sky at M3 is Arcturus, which is the recommended star to find the general area of where the cluster is. The other star I labeled forms a nearly-straight line with Arcturus and M3. That star, is given the Latin name Cor Caroli (Charles' Heart). It is the brightest star of the constellation Canes Venatici: the Hunting Dogs. Not to be confused with Orion's two dogs, Canis Major and Canis Minor, Canes Venatici (with the spelling of the first word slightly different) is two dogs within one constellation, albeit a very dim one.
Time: 11:29(.45) PM
Brief
Springtime is the best season to view the globular cluster M3, which transits high in the sky and near one of our brightest stars in apparent magnitude. With the zoomed-out image shown here first, we see the location of the cluster, at 28º north and therefore at our latitude, seen at 80º in altitude. It is the first deep sky object discovered by Messier, while the first two that he categorized (a nebula and another cluster in Taurus and Aquarius respectively) were discovered by others earlier. I will talk more about those in upcoming months, when they become visible during the summer mornings.
Looking in the same part of the sky at M3 is Arcturus, which is the recommended star to find the general area of where the cluster is. The other star I labeled forms a nearly-straight line with Arcturus and M3. That star, is given the Latin name Cor Caroli (Charles' Heart). It is the brightest star of the constellation Canes Venatici: the Hunting Dogs. Not to be confused with Orion's two dogs, Canis Major and Canis Minor, Canes Venatici (with the spelling of the first word slightly different) is two dogs within one constellation, albeit a very dim one.
Detailed
The second image here shows the cluster zoomed in with a field of 1º.
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| click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp. |
Although this doesn't help magnify the core too well, it does help fit the 48 arc-minute cluster into the field completely. As I have mentioned before when magnifying, it is best to not let contrast degrade. Therefore, magnifying too much not only shrinks the field and cuts off stars, but makes the core seem dimmer. If you want to still magnify enough to see the core of the cluster, limit it to a field between the "ballpark" of 0.7 and 0.8º at most; this will still give a good enough magnification range of roughly 90-100x for most eyepieces. When skies are clear and dark, as they hopefully are with the Moon out of the way at this hour, the cluster can be seen at its best. It is also good to not have moisture in the air, with humidity low.
I mentioned during my Pleiades talk awhile back, that open clusters are loosely bound by gravity; globulars such as M3 are tightly bound. At 35,000 light years away and magnitude 7, that can indicate how many stars this globular has: about half a million. Find out more stats about the cluster with this link:
http://messier.seds.org/m/m003.html
it is a huge gathering of stars, to say the least!
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