Monthly Messier Star-Hop; March #2
By Art Russell

This month we'll jump from the celestial twins, "Castor and Pollux," of Gemini, to the constellation of Cancer, "The Crab," as a preface which will lead us in May to the Virgo cluster of galaxies! In the process, we'll take a look at two of Messier's open clusters; M44 and M67; a double star, Iota Cancri; and a galaxy, NGC 2775; which you may be able to find even with smaller telescopes.

Star-Hop #1. M44, NGC 2632, "Praesepe" or "The Beehive Cluster"
Star-Hop #2. M67, NGC 2682
Star-hop #3. NGC 2775
Star-hop #4. Iota (i) Cancri

The way to Cancer is relatively easy under dark skies if you start in the constellation Gemini. Extend an imaginary line southeast from Gemini's prominent stars of Castor, Alpha Geminorum, and Pollux, Beta Geminorum, for a little less than 20 degrees, or the distance spanned by your outstretched hand held at arm's length against the night sky. There, you'll find the dim star Delta Cancri. You'll immediately notice that Cancer is a dim constellation. For best viewing, you'll want to get as far away as possible from city lights and light pollution in order to easily find this constellation.

Star-Hop #1. M44, NGC 2632, "Praesepe" or "The Beehive Cluster." Locating M44 from Delta Cancri is typically very simple. In fact, even under moderately light polluted skies, you'll typically be able to see M44 as a naked eye object well before you ever locate Delta Cancri . However, if you must star-hop, it is only about 2 degrees, or twice the distance spanned by your little finger held at arm's length against the night sky, to the northeast. Here, the glow of M44's many stars is immediately visible, even under a full Moon. Needless to say, adding even a little magnification, such as you might in using a set of binoculars, will immediately reveal a multitude of stars. In moderate sized telescopes, even more stars are visible and they may in fact take on the shape of a "Martini Glass" in appearance. However, don't use to big a telescope or add too much power. This is a large open cluster and with larger scopes or higher powers you will look through the cluster and miss out on its beauty!

Star-Hop #2. M67, NGC 2682. M67 is a much smaller and much dimmer open cluster than M44. You won't be able to see this open cluster with your naked eyes. If you can, please donate your eyes to me! However, even though M67 is 1/3 the diameter of M44, it is comprised of more than twice as many stars, although they are all much dimmer. Locate M67 by starting at Delta Cancri and extending an imaginary line a little less than eight degrees, or a little less than 4 times the distance between Delta Cancri and M44, to the southeast to find the dim star Alpha Cancri. M67 is located less than 2 degrees or twice the distance spanned by your little finger at arm's length against the night sky, due west of Alpha Cancri. You will be able to find M67 in a set of common binoculars, but you will only resolve a few stars. The remaining stars in this open cluster will appear as a nebulous haze. In moderate sized telescopes at moderate power, many of the stars will appear resolved, however, many more will still remain to be resolved at even higher powers.

Star-hop #3. NGC 2775. Other than Cancer's notable open clusters, M44 and M67, Cancer is really a constellation of galaxies, even though it doesn't have that reputation. In fact, under very dark skies, you can find as many as 9 galaxies visible within the boundaries of M44. However, to do so, you'll also need high powers in order to look through the open cluster to the galaxies beyond. In this star-hop, we're after more fascinating prey, the galaxy NGC 2775. Although this is a small galaxy, NGC 2775 should be visible under dark skies. NGC 2775 is conveniently located as an extension of the imaginary line you made in locating M67. As before, extend an imaginary line from Delta Cancri to Alpha Cancri. Extend the line from Alpha Cancri for a little more than 5 degrees, or the distance spanned by 3 fingers held at arm's distance against the night sky. Under dark skies you should be able to find the faint smudge of this galaxy in your field of view with a moderate sized telescope, although, with patience, you can also find this galaxy with smaller telescopes as well. For your best view, switch to higher powers.

Star-hop #4. Iota (i) Cancri. In our fourth and final star-hop, we'll track down a double star. Cancer has over 80 catalogued double stars. Of theses stars, Iota Cancri, offers a good color contrast between the two stars involved; yellow and blue. However, be warned, observing this double star is a challenge! You'll need to use your highest powers in order to get a proper look at this pair of stars; even then, it may not be enough. Try to observe this pair of stars on those evenings with the greatest transparency and best seeing (Remember, if the stars are twinkling a lot, your seeing stinks!). If you can separate the two stars, you'll find the smaller star is bluish in color, while the brighter star is yellow in color. Good luck on this pair; splitting the component stars is not easy as they are close together. Remember to try high powers and good seeing! Locating Iota Cancri is a straight-forward star-hop from Delta Cancri. Starting at Delta Cancri, extend a line due north for a distance of about 10 degrees, or the distance spanned by your fist held against the night sky at arm's length. Here you'll find Iota Cancri. As Cancer is one of the dimmer constellations, you shouldn't have too much difficulty locating Iota Cancri since there are so few other stars in the area. Once again, remember that this double star requires HIGH POWER. 300X or 400X would not be an unreasonable magnification to try. Let me know how it turns out! You can be sure that I'll be taking a look as well!