Two of the three objects this week — open cluster M50 and the Rosette Nebula (NGC 2237–9/46) — lie inside the confines of the constellation Monoceros the Unicorn. Credit score: Roen Kelly
The Beehive Cluster (M44) in Most cancers is a superb goal for naked-eye and binocular observers, open cluster M50 in Monoceros gives small-telescope homeowners good views, and large-telescope homeowners can hunt down the Rosette Nebula (NGC 2237–9/46), additionally in Monoceros.
Targets for Feb. 21–28
Bare eye: The Beehive Cluster (M44)
Small telescope: Open cluster M50
Giant telescope: The Rosette Nebula (NGC 2237–9/46)
Away in a manger
This week’s naked-eye object is the Beehive Cluster in Most cancers the Crab. As a result of this cluster is vibrant — magnitude 3.1 — it has acquired different correct names all through historical past. Messier made it quantity 44 on his well-known record of deep-sky objects that weren’t comets, so most novice astronomers at this time name it M44. And a couple of,000 years in the past, it was the Praesepe, the Latin phrase for manger.
You’d assume such a vibrant object can be obvious instantly, however, sadly, the Beehive lies within the ultra-faint constellation Most cancers. Really, one of the simplest ways to search out it’s to make use of three 1st-magnitude stars — however they’re not in Most cancers.
First, discover the “twin stars” Castor and Pollux in Gemini. Then, not fairly one-fifth of the best way throughout the sky to the east, find Regulus, the brightest star in Leo the Lion. M44 lies roughly halfway between them.
You gained’t see it along with your bare eyes below even a reasonably light-polluted sky. Though the Beehive Cluster shines at third magnitude, it measures greater than a level throughout. Meaning its gentle spreads out over an space equal to five.5 Full Moons. In case your eyes alone can’t choose it out, you’ll don’t have any downside recognizing it by binoculars.
Overlook-me-not
This week’s small telescope goal is open cluster M50 in Monoceros. You already know, Messier’s record is filled with spectacular objects — the Andromeda Galaxy is M31; the Orion Nebula is M42; and M51 is the Whirlpool Galaxy. In such illustrious firm, M50 would possibly really feel a bit intimidated.
Effectively, it shouldn’t. At magnitude 5.9, sharp-eyed observers below a darkish sky can spot this cluster with their bare eyes. By way of a small telescope at 100x, you’ll spot 50 stars in an space 12′ throughout. The brightest glows at Eighth magnitude, and plenty of extra Eighth- to Tenth-magnitude stars kind curving chains inside the cluster.
You could not have heard a lot about M50, however don’t overlook it. It’s a hidden gem that may reward you for observing it.
A multilayered winter flower
This week’s deep-sky object is the Rosette Nebula, which additionally lies in Monoceros. Most observers acknowledge it as a single deep-sky marvel. The Rosette, nonetheless, has 4 NGC numbers assigned to it by astronomers, and people don’t embrace the star cluster NGC 2244 at its heart. The 4 designations for the nebula are NGC 2237, NGC 2238, NGC 2239, and NGC 2246.
From a darkish website, you’ll first spot NGC 2244. A number of dozen stars — a half dozen brighter than Eighth magnitude — lie inside an oval area elongated northwest to southeast.
To greatest observe the Rosette Nebula, use a 10-inch or bigger telescope and an eyepiece that provides a magnification of 50x. Insert a nebula filter to dim NGC 2244’s stars. The nebula’s western aspect seems brighter. Right here, the ring’s internal wall seems straight with a tiny little bit of scalloping; the outer wall appears skinny with an extension to the northwest.
The Rosette’s jap aspect is far wider. A nebulous wall with a well-defined border kinds its northern edge. Though astronomers classify the Rosette as an emission nebula, your eye can even discover the various small darkish nebulae superimposed on the intense background.
