Up here in the northern half of the planet we will be seeking a pair of perennial favorite galaxies and an obscure open cluster in the northern portion of Ursa Major. Our southern friends will be focusing on the beautiful constellation of Centaurus. Within the centaur’s realm, they will be hunting down a trio of fine objects, an open cluster, planetary nebula and diffuse nebula.
(Northern Celestial Hemisphere)
This large and bright galaxy, along with nearby
Located about 10° northeast of mag 1.8 Alpha Ursae Majoris (Dubhe), one can use a line drawn from the “Dipper” stars mag 2.4 Phad (Gamma UMa) through Dubhe to the northeast to aid in locating this beautiful galaxy. Depending upon one’s sky quality this object can be easily within reach of binoculars. Even in small apertures one may pick up a broadly brighter core region surrounded by a diaphanous oval disk. . With increasing
The second largest member of the M81 Group is this disrupted spiral that is often referred to as the “Cigar Galaxy” because of its thin, elongated visual appearance. Known as a starburst galaxy because of its high level of stellar formation, this nearly edge-on spiral has most likely been disrupted through interaction with nearby M81. It is also known as Arp 337 from Dr. Halton Arp’s Catalogue of Peculiar Galaxies. Just like M81, it was discovered by Johann Bode in 1774.
This beauty is only about half a degree north of M81 and they can easily be seen within the same visual field of view at lower magnifications. While dimmer in visual magnitude than its neighbor, it has a higher surface brightness because of its smaller angular size. It too may be picked up in binoculars and small apertures, appearing as a thin, fairly large elongated glow. With increasing
This object is a bit of an obscure one. It lies along the line from Dubhe to M81, nearly 6.5° northeast of the bright star. This object is relatively unknown in terms of the riches of Ursa Major. In fact, in the Revised New General Catalogue (RNGC), it is deemed non-existent based on its appearance in
Visually, this cluster is not what I would call impressive. Nonetheless, I would not call it non-existent as it is listed in the RNGC. The cluster lies immediately north of the mag 7.9 star HD 90318, and to my eye it consists of two sub-groups of stars within its field separated by a mostly starless lane or void. Take a look at the below annotated DSS2 image to get a sense of this object. You can pretty much take it to the bank that this one will not impress you, but John Herschel spotted it, noted it and so should you!
(Southern Celestial Hemisphere)
This beautiful cluster is informally known as the Pearl Cluster, and is located not quite 1.4° north of mag 3.1 Lambda Centauri. This object was discovered by Nicolas-Louis de Lacaille during his time in South Africa (1751-52). He described it as "three faint stars in nebulosity." However, he was only using a ½ inch telescope at 8x. It was also observed by James Dunlop and John Herschel, both of whom saw it for its true nature.
Visually it is a spectacular cluster, with a dense central region. As
This very well known object is nicknamed the “Blue Planetary” for a good reason. Its prominent blue color is legend. In fact, it was first recorded as a “fine blue star”, by James Dunlop in 1826. Unfortunately he apparently he missed its non-stellar nature. John Herschel is credited with its discovery in 1834, describing it as "perfectly round; very planetary; color fine blue; .very like Uranus, only about half as large again and blue."
This planetary is truly a gorgeous object. It blue color is robustly apparent through the eyepiece as one observes its small round disk. The central star is a very dim mag 15.7, and beyond visual observation within the diffuse disk of the planetary. The nebula’s disk exhibits sharply defined edges against the background field and appears evenly illuminated. Its surface brightness is high, making it an excellent target even for smaller apertures. But it is the intensely blue color that is the most striking feature of this object. It truly is a stunning piece of celestial art work.
This well known and often imaged nebula complex is catalogued in two parts, though in all likelihood it could be a singular physical structure. In fact, the RCW and Gum catalogues both label these under a single identifier. In terms of the Index Catalogue, what is labeled as
Under dark skies this can be a delicate and fascinating object to observe visually, particularly when using either a narrow-band nebula filter or an O-III line filter. Those who do
Informally, depending upon the source, one or the other or even both can be found labeled as the “Running Chicken Nebula”. I have to admit, this moniker is totally lost on me, and apparently many others as well from what I’ve read. To my eye, looking at images of this complex, there is nothing to suggest a relationship to a fowl of any type. In fact, when I look at the below attached
Okay folks, there you have it for this month. I lay this challenge before you to use as you see fit. I hope you will take up the mantle and purse them to the extent possible. Some you likely have seen or imaged before, but perhaps I have given you something new to add to your nightly cruises. Good look and first and foremost, have fun!
