A Better Galaxy Guide: Early Spring
April 2009 :
We all know about the wealth of galaxies that populate the sky beginning around this time of year, but if you’re not an experienced deep-sky observer, where do you begin? There are so many catalog listings, seasonal magazine articles, great books by fine astronomy writers, innumerable blogs and observing websites, you name it—the information’s out there, all around us. So, too, are galaxies, but the vast majority of these island universes—lying several to many millions of light years removed from us—are impossibly faint little flecks of fluff against the night sky, invisible to small and medium-sized instruments and tough to locate and verify by even veteran amateurs. Maybe you’ve got a small scope or average binoculars and lack the wherewithal or knowledge to do serious deep-sky hunting. If you’re interested in finding some galaxies, their bewildering number alone—not to mention how hard most of them are to see at all—can make this a forbidding, nearly hopeless chore instead of a pleasant little exercise in amateur astronomy.
This situation prompted me to come up with a handy short list of mainly galaxies along with a few other worthwhile objects, things that are bright enough to actually see in smaller telescopes of 4-inch to 8-inch aperture. Most of my choices can, in fact, be readily seen in instruments of 5” or less; many can be glimpsed in binoculars of 50 to 80mm aperture or so. Naturally, your local observing conditions will dictate what can be viewed. Haze and skyglow from area light pollution, altitude of a given object above the horizon corresponding to optimal times of night to “catch” a better view through denser air down low, or interference from moonlight will be limiting factors. In April of this year, the Moon is at Last Quarter on the 17th and will be New on the 24th. Mid-to-late April will therefore be prime observing times.
I had several basic ideas in mind for planning the listing. 1) A band, or range, of right ascension running from approximately 7h 30m to 12h, west-to-east. This coincides with reasonable evening viewing hours in late April—all the constellations involved are well (or nearly so) presented with respect to altitude. 2) Selection of constellations both rich in bright galaxies and adjacent ones not ordinarily considered as favorable for easier galaxies. 3) Criteria of both brightness and ease of star-hopping to the chosen galaxies. Even so, every galaxy here ranks among the very best to be seen in its constellation. 4) Inclusion of certain important, highly worthwhile objects other than galaxies for those constellations lacking easily seen galaxies. (The very first object, NGC 2419 in Lynx, is a case in point.) 5) Ordering of object listings by right ascension within constellations featuring two or more objects. 6) Avoiding the listing of any galaxies too far south in declination to be reasonably detectable in a non-perfect observing locale, which is pretty much everywhere! 7) A separate section of potentially useful notes following the list—these serve as valuable star-hop suggestions for observers who might not own computerized scopes. (Only two objects on the list lack this accompanying information. A trio of galaxies in Ursa Major has no star-hop info and the final object on the list, NGC 2655, is not covered in the notes.) 8) Indication of pairs or groups of galaxies that are close together in one spot within a constellation—see the asterisks.
Altogether you’ll find 19 of the top-rated galaxies on this list, plus 2 open clusters and 1 each of a globular cluster, planetary nebula and red carbon star. A few fine galaxies in Draco and Camelopardalis were omitted due to placement in the sky at this time of year. The galaxy-rich constellations Virgo, Coma Berenices, and Canes Venatici are further east in RA than my selected group and are not as well seen in April; the month of May is better. Covering them entails a separate article for next month or next year, depending on my ability and time. This was a lot of work and I hope some of you will be able to make use of it!
Notes:
NGC 2419: 3.25° SE of mag 6.2 66 Aurigae. Hard to find and see; at E end of short row of two mag 7.5 stars. Highly significant and worth the effort —may be approximately 300,000 light years distant and qualify as an extragalactic cluster. Named the Intergalactic Wanderer.
NGC 2683: Marks NW “crook” of coathanger-type triangle with easy double star mag 4.2 Iota Cancri (which is SSW by 4.8°) and mag 3.1 Alpha Lyncis (at 6° to the ENE).
M67: One of the most ancient open clusters known and is a great novelty in this regard. Located 1.7° due W of mag 4.3 Alpha Cancri.
NGC 2775: Located 3.7° ENE of mag 3.1 Zeta Hydrae. (Look for “Head of Hydra” first.)
NGC 2903: Easily found at 1.5° due S of mag 4.3 Lambda Leonis.
M95: One of three bright galaxies forming a compact triangle, along with M96 and M105. All three can be seen together in a low power, wide field view. M105 is at the NE tip of triangle, midway between stars 52 and 53 Leonis, mag 5.5 and 5.3 respectively —M95 is at W tip.
NGC 3521: Located 0.5° due E of mag 6.0 62 Leonis.
M65: One of a pair of bright galaxies that can be seen in a wide field view along with M66, which lies just E.
M65 is midway between stars Theta and Iota Leonis, mag 3.5 and 4.0 respectively.
NGC 3344: Located 2.75° due W of the fine mag 4.3 double star 54 Leonis (separation of components about 7”) and midway between stars 40 and 41 Leo Minoris, mags 5.5 and 5.1.
NGC 3115: Find mag 3.6 Lambda Hydrae and go due N by 4° to the 0.2° wide pair of stars 17 and 18 Sextantis, each about ma 5.75, oriented W to E. NGC 3115 will be found 1.5° WNW of this pair’s center. This is the Spindle Galaxy and has an uncertain classification, thus my “?” after the S0. The shape suggests it may be a transitional type between a highly flattened elliptical and a lenticular S0 type of disc galaxy.
M48: Located by imagining it to be the southern tip of an equilateral triangle with mag 4.3 Zeta Monocerotis (about 3° to the NNW) and mag 3.9 C Hydrae (3.5° to the NE). C is the brightest of a compact little row of three stars close together.
NGC 3242: This is the famous Ghost of Jupiter, one of the most striking and brighter planetary nebulae in the entire sky. Located 1.8° S of mag 3.8 Mu Hydrae, it’s a splendid object even at the relatively low declination of -18° 38’. The greenish-blue color is a dead giveaway-hope you enjoy!
U Hydrae: A fine red carbon star located in the general vicinity of NGC 3242, to the NE by several degrees. U forms the northern tip of a triangle with Mu (about 4.5° to the SW) and mag 3.1 Nu Hydrae (4° to the SE). The period of this variable is about 450 days but the star stays sufficiently bright so as to be easily seen throughout its range in magnitude.
NGC 2841: Located about 1.8° WSW of mag 3.2 Theta Ursae Majoris.
M81: Also known as Bode’s Nebula. M81 is the brightest of a group of galaxies along with the strange Exploding Galaxy M82 (just due N of M81 and visible in the same very low power, wide field view) and NGC 3077, the faintest of these three, found 0.75° to the ESE of M81.
NGC 3184: Located 0.75° due W of mag 3.0 Mu Ursae Majoris.
M108: Located 1.5° SE of mag 2.4 Beta Ursae Majoris, Merak —the southern of the two Big Dipper “pointer” stars.
NGC 4125: Check star atlas; note how NGC 4125 forms an almost perfect triangle with mag 1.8 Alpha Ursae Majoris, Dubhe (lead “pointer”) and mag 3.3 Delta, Megrez. Should be a workable star hop.
