Welcome to the March challenge! I'll first give a brief list of the objects for this month's challenge, and then, in the spirit of the "EAA Observational Reports" thread, give "an observational reason" the objects were chosen.
March Objects
Open Clusters: M67, Berkeley 39
Globular Clusters: NGC 2419
Bright Nebulas: Sh2-311
Planetary Nebulas: Jones-Emberson 1, Abell 30, IRAS 09371+1212
Galaxies: EDIT: NGC 2903, NGC 2336, NGC 3187 (in Hickson Compact Group 44), M95
Observational Notes
I generally tried to select objects within 8-10 hours RA, plus or minus a half hour or so. For those of us in the northern hemisphere, the open clusters, globular clusters, bright nebulas, and planetary nebulas in the plane of the Milky Way are starting to disappear, soon to be replaced by all the springtime galaxies. So I included some of them as maybe our last chance to view these types of objects until summer arrives.
Open Clusters: M67 is a very beautiful open cluster; to me appreciating the beauty of an object is part of observing. It's also interesting because it's far from the galactic plane, which has allowed it to preserve the tightness of the cluster as it orbits our galaxy, and it's very old, 5 billion years old according to recent calculations. It also has a collection of "blue stragglers," stars that are on the blue side of the main sequence.
Berkeley 39 is even older, 8-10 billion years old. It also has blue stragglers, including (unusually) four binary systems.
Globular Cluster: NGC 2419, like some of the other objects in this month's challenge, is unusually positioned. It's 300,000 light years from the center of our galaxy, a distance exceeded by only a few other globs. It's also unusual in that it has a blue horizontal branch in the color-magnitude diagram; globular clusters typically have a red horizontal branch.
Bright Nebula: While I'm not aware of any unique feature of Sh2-311 (or associated open cluster NGC 2467), sometimes called the "Skull and Crossbones Nebula," it doesn't seem to get much attention. That alone might make it worth observing. It is pretty far south, which also might make it more of a challenge.
Planetary Nebulas: Jones-Emberson 1 was selected as a counterpart to Jones 1, part of the December 2022 challenge. Discovered in part by Rebecca Jones at the Harvard College Observatory before World War II. During the war, she served in the WAVES (Women Accepted for Volunteer Emergency Service). Jones-Emberson 1 also makes a good technical challenge, as it emits mostly in the OIII band but also has an H-alpha component. See if you can observe both.
The other two are interesting astrophysically (if that's a word). Abell 30 is a rare example of a "reborn" planetary nebula. The central star has temporarily become a red giant again. While it is very difficult to view the original outer shell (I viewed it only faintly after 20 minutes of stacking), the bright, irregular OIII core will be (I hope) visible.
IRAS 09371+1212 is known as the "Frosty Leo" nebula. Not only is it unusually far from the plane of our galaxy, it also has been hypothesized to contain crystalline ice. There is a bright core which should be visible; I found it to have an unusual color.
Galaxies: All of the selected galaxies are barred spirals. Things you might observe: Is the bar visible? Is there an inner ring around the bar? Is there an outer ring? How tightly wound are the arms? If you're motivated, you can try your hand at classifying the galaxies based on your observations, and then check this against how others have classified them. (Hat tip to user mintakaX for suggesting NGC 2336.)
Edited by steveincolo, 01 March 2023 - 11:55 AM.
