Monthly
Messier Star-Hop; March #3
By
Art Russell
"Lasciate Ogni Speranza Voi Ch'entrate!" Once again, the realm of galaxies approaches. Where seasoned amateur astronomers look forward to the arrival of old friends warmly remembered under the chilly skies of late winter and early spring, beginners avoid the area like a visit to the dentist office for a molar extraction without benefit of anesthesia. The realm of the galaxies, the Coma and Virgo clusters in the constellations Coma Berenecies and Virgo, respectively, need not be approached with fear and trepidation. However, you should approach it with a plan. Fail to have a plan, and you will be as surely lost as those poor souls entering Dante's Inferno.
This monthly Star-hop is the first of three in an odyssey into the heart of the realm of galaxies. Along the way, you'll learn the essential secret to star-hopping in this part of the sky. We'll start off early in the morning in the constellation Leo and then, using the galaxies M87, M84 and M86 as our guide, jump off to the galaxies M85, M88, M91, M98, M99 and M100.
Galaxy-Hop
#1. M86 to M88 (NGC 4501)
Galaxy-Hop #2. M88 to M91 (NGC 4548)
Galaxy-Hop #3. M86 to M99 (NGC 4254)
Galaxy-Hop #4. M99 to M98 (NGC 4192)
Galaxy-Hop #5. M99 to M100 (NGC 4321)
Galaxy-Hop
#6. M100 to M85 (NGC 4382)
At this point, I suppose, you're asking yourself what the secret to star-hopping in the realm of galaxies might be. In case you haven't already guessed, you don't star-hop with stars! You star-hop with galaxies! Depending on the size of your scope, you'll often find more galaxies in your field of view than you find stars. Of course this also means you need to have GOOD STAR CHARTS!! As a minimum, consider using a copy of Sky Atlas 2000. However, you'll be much better off using Uranometria or a set of custom printed finder charts.
So how to get started? Where to begin? Find the constellation Leo which culminates (crosses the zenith or gets as high as it ever does) on 15 March at 1 AM.
From the star Denebola, Beta Leonis, extend a line east-southeast to the star Vindamiatrix, Epsilon Virginis, in the constellation Virgo. You'll find the M84 and its close companion, M86, at the midpoint between these two stars. As a side trip, note the giant elliptical galaxy, M87, is only a little more than 1 degree east-southeast of M84.
Now the fun starts. We'll be using M86 as our starting point for galaxy hoping for this month and next month as well. Take time getting comfortable finding M86 as it is very easy to get lost galaxy-hoping in the fields of myriad galaxies in Virgo and Coma Berenecies. At this point, be sure you know size of the the field of view in your telescope's eyepieces. For comparison purposes, the distance between M84 and M86 is about 17 arcminutes. The distance from M86 to M87 is about 1.3 degrees, or a little more than 3 times the distance between M84 and M86. There are many galaxies in this area. For simplicity, I've excluded all galaxies dimmer than 11th magnitude in the following chart. As a general rule, the Messier galaxies are brighter than the surrounding galaxies, so you shouldn't have too much trouble finding your way during the Galaxy-Hops to follow. Remember, if you get lost, you can always start over at M86.
Galaxy-Hop #1. M86 to M88 (NGC 4501). Centering your telescope's field of view on M86, move to the northeast the appropriate number of fields of view to equal about 2 degrees. The third star-chart has a circle around M86 approximating a 1 degree field of view. In this case, I'd move my telescope a little more than 2 fields of view to the northeast to find M88. Observing at moderate power in the Atlanta Astronomy Club's 20 inch scope, M88 appears as an oblong halo with a hint of the nucleus visible in averted vision. The galaxy seems oriented northwest to southeast and is very visible.
Galaxy-Hop #2. M88 to M91 (NGC 4548). M91 is a little less than 1 degree, almost due east of M88. Simply move your scope the appropriate number of fields of view while watching through your eyepiece, and you should find M91. M91 should be visible even in smaller telescopes, but you can expect it won't be very prevalent. At moderate magnifications you'll find that M91 presents a uniform glow with a very small nucleus. Even at higher powers the galaxy doesn't reveal much, although it may appear a bit mottled.
Galaxy-Hop #3. M86 to M99 (NGC 4254). Returning to M86, the distance to the next galaxy presents an opportunity to get lost. Remember where you found M86 if you loose your way. Starting at M86, move your telescope a little less than 2 and a half degrees northwest. About half way there, note two of the brighter stars (10th magnitude) ;-() in the field of view which will help guide you there. At moderate magnifications, M99 will present a bright nucleus with a halo which fades rapidly. At higher magnifications, the nucleus fades in prominence, but it leaves you with a suggestion of mottling within halo.
Galaxy-Hop #4. M99 to M98 (NGC 4192). M98 is only a little more than 1 degree to the northwest of M99. Once again, move your telescope the appropriate number of fields of view while observing through your eyepiece. M98 will be very prominent. M98 is relatively easy identify. At moderate magnifications, it is very elongated from the northeast to the southwest. It may also appear to have a hint of nucleus visible in averted vision. At higher powers, the nucleus may become visible in direct vision as well as some suggestion of mottling in the halo of the galaxy.
Galaxy-Hop #5. M99 to M100 (NGC 4321). Starting once again at M99, M100 is a little less than 2 degrees to the northeast. At moderate magnifications, M100 appears to have a bright nucleus and halo. At higher magnifications, the halo is more prevalent as the nucleus fades in prominence.
Galaxy-Hop #6. M100 to M85 (NGC 4382). Starting at M100, M85 is about 2 and a half degrees to the northeast. At moderate magnifications M85 appears small, but brighter compared to most of the other galaxies nearby. Keep this Galaxy-Hop handy for the next few months as the Realm of Galaxies will be well situated for easy viewing. Most of all, remember how to find M86 and you'll never be lost under in this part of the sky.