A beauty and her “beasts”

Cassiopeia the Queen shines high in the northern sky after sunset on winter evenings. Next to the hourglass of Orion now rising in the southeast, Cassiopeia’s striking W-shaped asterism this time of year is one of the night sky’s most striking and easily recognizable star patterns. Her regal placement on these cold January nights seems paradoxical. We don’t recognize her as a snow queen, but as the heaven’s queen of Ethiopia, an African nation spotted with lowland deserts burning under a near-equatorial Sun.
 
If that thought is not enough to warm your heart’s cockles, look to Beta (β) Cassiopeiae, the 2nd-magnitude star marking the Queen’s right hand in ancient Arab tradition. Its name, Caph, derives from the Arabic al-Kaff al-Khadib, which means “the Stained Hand.” (It might refer to the Arab practice of women painting their hands and feet with henna to protect their skin from the Sun’s heat.)

Of course, that leads us to a mystery. Why would Arabian astronomers have depicted a white F-type star as something with a reddish tint? I have never seen the reason discussed anywhere, but I have my own thoughts on the matter. Caph is the northernmost star in the bright W-shaped asterism, which is circumpolar from mid-northern latitudes, so the star never sets.

But as Earth turns, and the celestial W swings counterclockwise around the North Celestial Pole, Caph is the first star in the W to dip toward the horizon. There the Queen’s hand reddens due to atmospheric effects (especially near dusty desert regions); it’s as if the celestial beauty thrusts her hand earthward each night to scoop up the dye, tinting the fingers of her right hand first in the process.

Two visual “beasts”
Despite the Queen’s visual allure, she hides among her milky folds two tiny deep-sky wonders that are truly “beastly” to see. Both are within 1.5° of her dyed right hand. They serve as tests of not only your sky’s darkness, but also the light grasp of your telescope and the keenness of your sight. Get ready to squint.
 
vdB 1: Only some 30′ east-southeast of Caph is one of the heavens’ least-known reflection nebulae — van den Bergh 1 (vdB 1). Searching for it with my 5-inch Tele Vue refractor has become one of my favorite winter sports. It’s a tiny glow only 5′ across, but that’s not what makes this nebula difficult to see. The problem is that its shine gets drowned out from the light of three 9th-magnitude stars in a roughly 5′-wide triangle. Any haze or moisture in the atmosphere will diminish your chances, especially if you’re using a small telescope.

To spot it yourself, start by using the lowest power magnification possible. The more concentrated the view, the more apparent vdB 1 should appear. The feeble glow really looks like warm breath on a cold eyepiece — so hold your breath (but not too long). You’ll know if you’re truly seeing the nebula when you can’t find a similar haze around other comparably bright field stars. So move the telescope and try to spot stellar pairings for comparison.
 
If you’re using powers near 100x, I suggest first looking for the nebulosity surrounding the solitary 9th-magnitude sun at the northeastern end of the triangle. In case vdB 1 is not on your star chart, it’s located at right ascension 0h11m; declination 58°46′.

IC 10: While most observers recognize Cassiopeia for its wealth of nebulae and star clusters, it also has a galaxy within its boundaries: the little irregular system IC 10. Although the 10.3-magnitude galaxy lies only about 1½° from Caph, the 7′ by 6′-wide glow escaped the gaze of early telescopic pioneers until Lewis Swift discovered it October 8, 1887, with the 16-inch Clark refractor at Warner Observatory in Rochester, New York. Swift reported the discovery in an 1888 issue of Astronomische Nachrichten; it was one of 100 new nebulae found after the publication of the New General Catalogue. “For the most part,” Swift wrote, “they are exceedingly difficult objects, requiring exquisite seeing, prolonged scrutiny of the field, and an eye trained specially for the work.”

Swift went on to describe IC 10 (the 10th object in the Index Catalogue), as a “faint star involved in an extremely faint and very large nebula.” I’m confident small-telescope users will find the galaxy an enjoyable challenge. In their Observing Handbook and Catalogue of Deep-Sky Objects (Cambridge University Press, 1998), Christian B. Luginbuhl and Brian A. Skiff found IC 10 faintly visible in a 6-inch telescope, and I have spied it in my 5-inch.
 
Based on my view of the galaxy, I would say take heed of Swift’s initial advice on the visual requirements necessary to see this dim and diffuse object. You’ll find it at right ascension 0h20m; declination 59°18′.
 
By the way, after Swift reported his discovery of IC 10, nearly half a century passed before Nicholas U. Mayall identified the “nebula” in 1935 as an extragalactic system. A year later, Edwin Hubble, who once called IC 10 “one of the most curious objects in the sky,” proposed that it might belong to the Local Group. Not until another 30 years had passed did radial velocity and distance measurements confirm Hubble’s suspicion.
 
Astronomers now know that IC 10 is an irregular galaxy 2.29 million light-years distant. Its morphology resembles that of the Large Magellanic Cloud. But whereas that object orbits our Milky Way Galaxy, IC 10 orbits the Andromeda Galaxy (M31). IC 10 is, in fact, the nearest starburst galaxy to us.

As always, let me know what you see, and don’t see, at someara@interpac.net.