CONSTELLATION GUIDE |
"GO TO"....VIRGO
And the Maiden's Hope Chest Filled With Galaxies Galore....!
From: sherrodc@ipa.net (Clay Sherrod)
For the fourteenth Constellation Guide, "GO TO VIRGO" of the series "GO TO GUIDES for the ETX and LX 90 Telescope Users" we will continue to examine the vast wealth of extraordinary galaxies that present themselves in this large region of sky. In our last installment on Coma Berenices, the north of Virgo, (see http://www.weasner.com/etx/ref_guides/coma-berenices.html) we examined scores of galaxies, both elliptical and spiral that grace the skies in that tiny constellations and star cluster known also as "Mel 111." Here, we extend that galactic search into our southern skies, low areas for most northern hemisphere observers, and unfortunately frequently ignore because of this low altitude!
But for deep sky enthusiasts, this is one area that should NOT be turned away from! Even in this brief tour, we will look at over 35 galaxies! That is in addition to the nearly 30 from the Coma Berenices "GO TO" TOUR. As with that previous article, I will be listing about 25 ngc galaxies in "abbreviated form," that are in ascending Right Ascension order and by ngc listing. In addition, the brightest and most spectacular and interesting objects will be discussed in detail as usual.
Note from the sky chart included here that the CELESTIAL EQUATOR passes directly through the middle sections of Virgo. This is the reading "0" degrees on your properly adjusted declination setting circle. All angles NORTH of this equatorial line are positive ("+") and all angular measures (declinations) south of the celestial equator are negative ("-"); hence you will see references in this "GO TO" GUIDE to both "+" and "-" declinations for celestial objects.
Also note that the ECLIPTIC (the band in which all the planets, sun and moon appear to move relative to Earth) passes from southeast to northwest through this large constellation, passing only about 2 degrees north of bright SPICA.
The ancient Greek legends have given rise to our association of this star pattern (or perhaps originally with the purity of the WHITE star, Spica in all its brilliance in a star-void field. To them, and the Romans, the Greek goddess Astraea was immortalized among the stars in this constellation. The daughter of Zeus, Astraea was the last of the immortal Greek gods to leave the mortal Earth, after which no further direct contact between mankind and the gods would ever take place again.
Even in ancient Egypt, this star - and hence the entire constellation - was associated with a maiden and her purity and innocence, as it honored the Nile goddess Isis; indeed, the ancient ruined Egyptian city of Akhenaton and its temples appear to have been aligned and built in relation to the rising and setting of the bright star Spica in her honor. The Pharaohs knew the constellation as a "devoted wife," or the "most dedicated wife," while the Babylonian stargazers gave Spica and her starry regime the distinction of being the "Queen of the Stars." Even the Christian religion has honored the bright star as the Madonna.
It has always been my opinion that - taking nothing from the beauty of this star - that the isolation of Spica among the springtime stars and preceding the bright and rich Milky Way is the primary factor resulting in the undying attention and legend throughout history that is associated with Spica...... for the constellation itself is a very vague and uninteresting mildly-visible group of stars!
It is what you DON'T see in this area that is the most interesting. The "COMA-VIRGO CLOUD OF GALAXIES" dominates the north-western realm of Virgo and the southern portions of Coma Berenices. Literally millions of galaxies seem to occupy this region, most at a distance of some 42 MILLION light years away. On a very dark, moonless night, merely scan slowly with any of our telescopes at very low magnification and wide field eyepieces to see hundreds of "faint fuzzies" that are islands in the sky harboring hundreds of millions of stars each. In Virgo alone there are at LEAST 50 galaxies visible in the smaller telescopes.....over 100 in the ETX 125 and above. The most "crowded area" of this huge "mega-galaxy of galaxies" is located at about 12h 24m in right ascension, just at the Coma-Virgo border (see the widefield photograph below taken through the 48" Schmidt camera of Palomar Observatory).
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Each GO TO object in Virgo is discussed for your telescope regarding the type of conditions necessary for you to view it optimally for discern the very faintest details.........magnifications and aperture necessary for most objects, and much, much more. This is YOUR complete GUIDE to get you on your way to exploring the many hundreds of galaxies that are clustered in Virgo. The following listing of "BEST" objects contains the finest or most interesting....as with our "GO TO" TOUR of Coma Berenices, there is ALSO a bonus comprehensive listing of ALL NGC GALAXIES (they are on your AutoStar) that can be seen in at least one or some of our telescope size ranges *(faint ngc objects that are NOT visible in at least the LX 90 are NOT included in these "GO TO" TOURS)*.
Use this attached star chart and the following Guide as an excellent reference for your next star party itinerary, or a beginning for further study into the thousands of objects visible in this part of the sky. Truly these extensive Constellation Study Guides will most definitely put your AutoStar to work for you in the most efficient and enjoyable way possible! As a matter of fact, MANY AutoStar users are now programming their own "Tours" based on these guides, using each constellation as a separate GO TO Tour for the AutoStar library that can be added in or deleted through the main edit screen on your PC or MAC computer.
We hope you enjoy these comprehensive GUIDES to touring the constellations via your AutoStar and its computer-driven telescope. Each new installment is complete with diagrams, charts and illustrations that you will find nowhere else. Please let us hear YOUR feedback and your observations of each and every constellation after YOU have toured its vast reaches of our skies!
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YOUR VIRGO CONCISE DIRECTORY OF INTERESTING OBJECTS -
There are literally thousands of fantastic galaxies in Virgo and surrounding constellations, from wide field to telescopic. Because of the great number of galaxies, it was very difficult to select (and limit) the number of objects for our "GO TO" TOUR. Only the best and in some cases, most challenging, objects are chosen for this brief tour. The large number of galaxies made it prohibitive for me to include the myriad of wonderful double and multiple stars that I would normally have considered for this Guide. As can be seen with the photograph below (courtesy Palomar Observatory, 48-inch Schmidt Camera), there are galaxies virtually "crammed" into every field of view....the darker the skies, the better the view! The larger the telescope....the more the galaxies...!
I have chosen the finest (or most interesting) 17 objects in this VIRGO "GO TO" TOUR; as with all GUIDES, all objects listed below will be visible in all telescopes (some naked eye) from the ETX 60 through the LX 90; of course larger apertures may "show" an object a bit closer and "better," but frequently a wide field and low power view is more desirable than aperture for FINDING THESE GALAXIES!. Indeed, I strongly encourage you first FIND the galaxy, or its approximate location through your GO TO function with your lowest power and then - once IDENTIFIED positively - move up slowly in steps with magnification.
You will find that there is an "optimum magnification" with which to observe each and every galaxy. Too much "power" and you will darken the object as well as the field of view; not enough "power" and there might not be enough contrast between the dark background sky and the faint image of the "faint fuzzy" galaxy! Once your eyes are fully dark adapted, you will even be able to see fainter and fainter galaxies that at first might not even be glimpsed! I have found through practice with galaxies of this brightness and size that about 15x per inch aperture is PERFECT for good direct viewing once found (36x for the ETX 60/70; 55x for the ETX 90; 75x for the ETX 125; and, 125x for the LX 90).
With all deep sky objects, and particularly these small and faint galaxies, avoid attempting to observe when the moon is in the sky, even a very thin crescent, as its brightness in the sky will overshadow the very dim contrast afforded by even the brightest deep sky object; if you see the object at all against moonlight, you will NOT see the subtle outlying areas or the full detail of what is presented.
The convenient sky placement of Virgo lends itself well to very good and long-period observing for ETX and LX 90 users both north and south of the equator. When rising about dark in the east (mid-spring) it will remain in the sky throughout the night, transiting the meridian at about midnight during that season. All deep sky objects and difficult double stars are ALWAYS best observed when they are located nearly overhead (or as high in the sky as possible), thus requiring the observer to look through the thinnest portion of the Earth's "lens" of atmosphere and haze. Hence, northern hemisphere observers will want to wait until the constellation transits the meridian to provide as high a view as possible; fortunately for those north of the equator, most of Virgo's faint galaxies are located "high" in the constellation, above the "0" degree celestial equator.
As with all of the "GO TO" TOUR constellation lists, I recommend a good star atlas and/or chart which will list all the finest objects, constellation-by-constellation. One very handy reference guide is the PETERSON FIELD GUIDE TO THE STARS AND PLANETS, which features complete lists with declinations, right ascensions, magnitudes, and all pertinent information for you to expand your observing horizons beyond this brief GUIDE.
Note that your AutoStar will NOT have every object listed on every constellation GO TO tour....this is intentional. You can access some of the most interesting objects of the sky directly from their coordinates. It is quite simple as you merely enter these coordinates as follows in the 10-step process:
1) Press the "MODE" key and hold down for 3 seconds and release;
2) Displayed will be the current Right Ascension and Declination of the center of field of view of where your telescope is presently pointed (assuming that you have properly aligned from "home position");
3) [NOTE: if you have the Meade electric focuser attached to any of the ETX or LX telescopes, holding down the "MODE" key will bring up the "Focus" command first....merely scroll (lower right scroll key) down one step to access the RA and DEC to enter your desired coordinates]
4) Press the "GO TO" button on AutoStar;
5) This will change the display and you will note the cursor blinking over the first digit of RIGHT ASCENSION (R.A.); merely use the number keys and dial in the R.A. of the object you are searching for;
6) When done, press "Enter;"
7) This moves the blinking cursor over the "DEC" coordinates;
8) [NOTE: the declination, unlike R.A., can be either positive or negative and you will see the "+" or "-" sign displayed depending on where your telescope is aimed at that time; if it is NOT the desired setting (plus or minus), merely use your arrow key to move the blinking cursor OVER the "+" or "-" sign and change by using either of your lower corner SCROLL KEYS;
9) Proceed to enter the DEC using number keys;
10) Press either "Enter" or "Go To" when finished and the telescope begins slewing to your desired object!!
The constellation tour Star Chart above (click on and save to a file on your PC; then open it and re-size to fit the page and print for a very handy at-the-scope star chart) will get you started on your journey for this constellation.
Following is the concise object list for your "GO TO" TOUR of VIRGO; you may wish to find the majority of the objects from the AutoStar Library (for example, you can easily go to the "Sombrero Galaxy" if you pull up "Object/Deep Sky/Messier Object/..type in '104'...." and then press "Enter", followed by "GO TO" to access this very nice and bright edge-on galaxy. On the other hand, if you want to experiment and become a "better AutoStar user" try entering the exact R.A. and DEC coordinates of that object as described above after holding down the MODE key. You will find the accuracy of entered GO TO's to be somewhat less than those stored in AutoStar, but the capability of acquiring unlisted objects is fantastic!
Of course, for named objects such as the "Sombrero", you can also merely go to "Objects / Deep Sky / Named...." and then SCROLL downward until reaching the name "Sombrero Galaxy" and then press ENTER to GO TO that object!
OBJECT 1: very bright star - SPICA (alpha Virginis) - R.A. 13h 23' / DEC (-)10 54 - Magnitude: 1.0, beautiful white OBJECT 2: double star - PORRIMA (gamma Virginis) - R.A. 12h 39' / DEC (-)01 11 - Mags: 3.6 & 3.6, getting close! OBJECT 3: variable star - S Virginis - R.A. 13h 30' / DEC (-)06 56 - Mag: 6.3 to 13.2, 378 days OBJECT 4: variable star - R Virginis - R.A. 12h 36' / DEC +07 16 - Mag: 6.2 to 12.1, 146 days - good star! OBJECT 5: globular cluster - ngc5634 - R.A. 14h 27' / DEC (-)05 45 - Magnitude: 10.4 - tough, but visible in ETX 90! OBJECT 6: elliptical galaxy - Messier 49 (ngc4472) - R.A. 12h 27' / DEC + 08 16 - Magnitude: 8.6 OBJECT 7: spiral galaxy - Messier 58 (ngc4579) - R.A. 12h 35' / DEC + 12 05 - Magnitude: 9.2, good object for all OBJECT 8: elliptical galaxy Messier 59 (ngc4621) - R.A. 12h 40' / DEC + 11 55 - Magnitude: 9.6, round, starlike OBJECT 9: elliptical galaxy - Messier 60 (ngc4649) - R.A. 12h 41' / DEC + 11 49 - Magnitude: 8.9, bright, easy OBJECT 10: spiral galaxy - Messier 61 (ngc4303) - R.A. 12h 19' / DEC + 04 45 - Magnitude: 10.1 OBJECTS 11: two elliptical galaxies - Messiers 84 & 86 - R.A. 12h 23' / DEC + 13 10 - Mags. 9.3 & 9.6 - very nice pair! OBJECT 12: huge elliptical galaxy - Messier 87 (ngc4486) - R.A. 12h 28' / DEC + 12 40 - Mag. 9.2, very large oval! OBJECT 13: bright elliptical galaxy - Messier 89 (ngc4552) - R.A. 12h 33' / DEC + 12 50 - Mag. 9.5 - round & bright OBJECT 14: spiral galaxy - Messier 90 (ngc4569) - R.A. 12h 34' / DEC + 13 26 - Mag. 10.1 very elongated oval OBJECT 15: "SOMBRERO GALAXY" - Messier 104 (ngc4594) - R.A. 12h 37' / DEC (-)11 21 - Mag. 8.7 - Interesting! OBJECT 16: 3C 273 Quasar! - R.A. 12h 27' / DEC + 02 19 - Magnitude 12.8 - Tough, but WORTH the try!! OBJECTS 17 THROUGH 41 - NGC GALAXIES IN VIRGO (other than those listed above) listing of "ngc" galaxies in VIRGO in order of RIGHT ASCENSION (and NGC # order) visible in our scopes: NOTE: These NGC galaxies are NOT detailed in the following "Visual Guide" as are those Objects 1-11 listed above...use the abbreviated descriptions as they follow the order: NGC# / R.A. / DEC / MAGNITUDE / SIZE (in minutes arc -'-) / GALAXY TYPE (S=spiral, E=ellipt;, P=Irr.) ngc4030 / 11 57 / -00 49 / 11.0 / 3.1 X 2.2 - spiral, face-on, ETX 90 (barely) and above ngc4216 / 12 13 / +13 25 / 10.4 / 7.4 x 0.9 - edge-on spiral, good for ETX 90 and above, cigar-shaped! ngc4365 / 12 22 / +07 36 / 11.1 / 1.3 x 1.0 - very tiny and dim elliptical, starlike. ETX 125 and LX 90 only ngc4429 / 12 25 / +11 23 / 11.2 / 3.3 x 1.0 - spiral, very faint, LX 90 only ngc4438 / 12 25 / +13 17 / 10.8 / 8.0 x 6.3 - spiral, VERY large and face-on; visible in ETX 90, but tough ngc4473 / 12 27 / +13 42 / 10.1 / 1.6 x 0.9 - tiny elliptical, but bright. Starlike in all scopes, fuzzy ngc4517 / 12 29 / +00 21 / 12.0 / 8.9 x 0.9 - edge-on spiral, nice but too faint, tough even in LX 90 ngc4526 / 12 32 / +07 58 / 10.9 / 3.3 x 1.0 - small elliptical, fuzzy blob in larger scopes, starlike in ETX 60 ngc4527 / 12 32 / +02 56 / 11.3 / 5.3 x 1.0 - small spiral, only seen in 8" scope ngc4535 / 12 32 / +08 28 / 10.7 / 6.0 x 4.0 - large face-on spiral, can be seen in ETX 90; nice in ETX 125 + ngc4536 / 12 32 / +02 28 / 11.9 / 6.9 x 2.6 - large but VERY hard, even in LX 90 ngc4546 / 12 33 / -03 31 / 10.0/ 1.8 x 0.8 - very tiny, but fairly bright elliptical, visible in all scopes ngc4596 / 12 37 / +10 27 / 11.4 / 2.8 x 2.2 - barred spiral, very faint but barely seen in the ETX 125 ngc4636 / 12 40 / +02 57 / 10.4 / 1.4 x 1.3 - small starlike fuzzball, visible in ETX 90 and larger scopes ngc4654 / 12 41 / +13 23 / 11.2 / 4.2 x 2.2 - elongated spiral, very faint but can be seen in ETX 125 ngc4666 / 12 43 / -00 12 / 11.4 / 3.8 x 0.8 - near edge-on spiral, only visible in LX 90 and larger scopes ngc4697 / 12 46 / -05 32 / 9.6 / 2.2 x 1.4 - small oval elliptical, but bright enough for ETX 60/70 and above! ngc4699 / 12 47 / -08 24 / 9.3 / 3.0 x 2.0 - nice spiral, small and visible in all scopes, oval glow ngc4753 / 12 50 / -00 55 / 10.8 / 3.3 x 1.1 - Spiral, tilted; visible as a smudge in ETX 90; not bad in LX 90 ngc4762 / 12 50 / +11 31 / 11.0 / 3.7 x 0.4 - very thin edge-in spiral, very faint and tough in LX 90 ngc4856 / 12 57 / -14 46 / 11.8 / 2.0 x 0.7 - unusual "squashed" oval elliptical; very hard even for LX 90 ngc4958 / 13 03 / -07 45 / 10.9 / 1.7 x 0.7 - elliptical, can be seen as small smudge in ETX 90 and above ngc5363 / 13 54 / +05 29 / 10.7 / 2.0 x 1.4 - tiny elliptical, but bright enough for ETX 90 ngc5566 / 14 18 / +04 11 / 10.4 / 5.6 x 1.1 - needle-like spiral edge on, bright enough for ETX 90, high power ngc5846 / 15 04 / +01 48 / 10.5 / 0.9 x 0.9 - smallest elliptical you will see! Starlike....PERIOD.
....AND NOW ON WITH THE SHOW!! (refer to the Virgo Star Chart for all the objects described in detail on the "Guide")
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A VISUAL GUIDE TO OUR DEEP SKY OBJECTS IN VIRGO
Object 1 - Very Bright Star - "SPICA" (alpha Virginis)
Our starting point for every "GO TO" TOUR is always (or usually!) the brightest star of the constellation or region and Virgo holds no exception. However, Spica holds special honors in that much of the ancient lore of the Virgo constellation is likely attributable to the STAR ITSELF, rather than perhaps the pattern of stars making up the asterism we know as "Virgo" (see above). It is the bright white-blue of this diamond-like star that is captivating. Add to that the fact that Spica appears to "stand alone" amidst an otherwise star-poor and uninteresting area of the sky to the naked eye.
Spica is the only "true" 1st magnitude star of the skies....it has the honor of having an exact visual magnitude of 1.00. Because of its proximity to the celestial equator, Spica is one of my favorite stars for testing the tracking accuracy of telescope drive systems during spring and early summer months. Center you polar-mounted telescope on Spica when it is on the meridian (the imaginary line stretching across the sky from DUE SOUTH to DUE NORTH) with a very high power eyepiece and let your telescope track it for about 10 minutes. Ignoring all drift in the east-west direction (right ascension), if Spica moves NORTH in your eyepiece, your polar mount is aimed too far to the WEST....if it moves SOUTH, then your polar axis is aimed too far EAST!
At a distance of about 240 light years, Spica has depleted a great amount of its primordial hydrogen, now depending on Helium as its primary food source. Although the seemingly unfailing associations of this star to an unblemished maiden or goddess has prevailed, the actual name "SPICA" has derived from the Latin of the same name: "...spicum" or "spiculus" meaning "the ear of grain." This association refers to the traditional Greek art in which the Virgin is holding a large handful of wheat in one hand, of which Spica is the principal "grain of wheat!"
Object 2 - "Porrima" - (gamma Virginis) - A Very Tough Double that is closing fast!
You "may" or may not be able to resolve this star. Look for TWO equal 3.6 magnitude stars closing in on one-another for gamma Virginis. Porrima is a double star with a period of 171 years. In 1910, the first pass of Halley's comet of the twentieth century saw with it Porrima's two stars at their widest separation possible, over 6" arc. It likely was a beautiful sight...but not for long as the secondary star continued its long loop around star "A" and is now closing fast. Look for the stars oriented in an almost E-W line to one-another and of equal magnitude. In the ETX 125 and LX 90 I can clearly see some separation of these two stars, but the ETX 90 can clearly see and elongation of the two stars in that orientation. But you must look NOW....in 2007, the stars will appear so close together from Earth that they will appear only as ONE star! In reality, the stars on that year will still be 270 million miles apart from one-another in space. The star Porrima honors the goddess of Sage or Prophecy from the Arabian stargazers. However, the name is derived from the Arabic "Zawiat al Awwa", or the "angle" denoting the stars that comprise the heart of Virgo: Epsilon, Delta, Gamma, Eta and Beta.
Object 3 - A Classic Variable Star - S Virginis
For those of you who have NOT tried their hands at observing and monitoring variable stars.....you really don't know what you are missing. Not only is it exciting compiling your own data and light curves from the star's magnitude changes, but YOU can contribute much to the science of stellar astronomy and astrophysics through your regular observations of stars like S Virginis. I have chosen this star (as well as the next one following) for this "GO TO" TOUR because of three factors: 1) the star's brightness changes go from 6.3 to 13.2 magnitude, easily observable in the ETX 90 and larger telescopes all the way through its cycle; 2) its cycle requires 377.9 days to complete, thereby making it "easy" to observe, requiring an estimate only every TWO weeks!; and, 3) the star is easy to locate. To first locate the star, and to make estimates when the star is at its brightest, we use the "a" or finder chart. Click on the link to the American Association of Variable Star Observers (AAVSO) web site for this "a" chart and copy to file the chart found at:
http://charts.aavso.org/VIR/S_VIR/SVIR-A.GIF ; merely open that file and resize the chart to print on a standard piece of paper. Now....once you have located this star using the "a" chart, you will want a MORE DETAILED, or "closer" chart providing fainter stars and more of them for estimating when the star is at dimmest, or midway between maximum and minimum. For that, the AAVSO "d" chart found at
http://charts.aavso.org/VIR/S_VIR/SVIR-D.GIF will provide a more narrow field of view concentrating on a field of fainter stars for that purpose. For a complete discussion on the importance of variable star observing, the techniques for ETX and LX 90 users and a beginner's guide to select stars, you may find a thorough discussion from my "Observing Variable Stars" here on this web site at http://www.weasner.com/etx/ref_guides/variable_stars.html .
Object 4 - Another GREAT Variable Star - Only requiring HALF the time! R Virginis
Also a long period variable like S Virginis above, R Virginis is also a classic variable star....mostly predictable, with impressive variations.....but this one only requires HALF the time as S Viriginis! With a period of only 145.5 days, and a wide magnitude range from 6.2 to 12.1, this star can be monitored easily in the ETX 60 and 70 scopes as well!
The light curve shown above for R Virginis demonstrates its very rapid increase to brightness and equally sudden diminish from near-naked-eye visibility to a faint 12th magnitude! At its lowest, the star only "rests" at minimum for less than a couple of days! It is a "Mira-type" star, being a pulsating star that grows from pressure and subsequently diminishes in size from its own weight and gravity. Its short period is only HALF of a typical "Mira-type" star. The "a" finder chart from the AAVSO for this nice variable star is found at: http://charts.aavso.org/VIR/SS_VIR/SSVIR-A.GIF , while the more detailed "c" chart showing fainter stars to follow the light changes into minimum is located at http://charts.aavso.org/VIR/R_VIR/RVIR-C.GIF .
Object 5 - NGC 5634 - Our "Token" Globular Cluster in Virgo!
It may not be the brightest....or the biggest...and it certainly is NOT a show-stopper. But NGC 5634 is the ONLY globular star cluster in Virgo, and in this region of sky! With the overwhelming concentration of bright and large globular clusters in Ophiuchus not far away, this lone straggler has this lonely distinction. NGC 5634 (found on your AutoStar: OBJECT / DEEP SKY / NGC OBJECT....[scroll to] listings) is actually bright enough at magnitude 10.4 to be seen in even the ETX 60, but with some difficulty. Its entire size is ONLY 1.3' arc! Thus, it will appear like a very dim fuzzy star in that telescope; the ETX 125 and LX 90 show this a bit better (and larger), but with absolutely NO star resolution. At 23,000 parsecs away, this is one of the most remote of our Milky Way's globular clusters.
Object 6 - Let the Galaxy Show Begin! Messier 49 - Elliptical Galaxy
At magnitude 8.6 this is one of the brightest, largest (about 5' arc) and easiest of all elliptical galaxies for amateur telescopes. I appears as a round glow in the smaller telescopes, but the ETX 90 will begin to show a VERY bright star-like center to this galaxy. In the ETX 125 and LX 90 the form is very interesting, as the circular glow of this shape dims very rapidly toward its edges with NO detail seen, except a clear star-like center. Like most galaxies of the Coma-Virgo group, this elliptical is an incredible 42 MILLION light years away. Because of its brightness, this is a great example of an elliptical galaxy for our smaller GO TO telescopes!
Object 7 - Messier 58 - a VERY Nice Spiral Galaxy
I re-visited this galaxy for the first time in years from Petit Jean Mountain on May 20. The sky was one of those 3-dimensionally dark events and the galaxies of Virgo were just incredible, showing MUCH detail in the LX 90 and presenting wonderful challenges in my ETX 125. Messier 58, a barred spiral, shows a distinct "bar" across its middle in the ETX 125 at about 125x, and clearly with 100x in the 8" scope. At medium power, about 75x to 100x, in the ETX 90 and ETX 125, you can barely "imagine" some very delicate outlying spiral arms at the north and south peripheries....they ARE there! Use averted vision to occassionally detect this wispy arms! At low power in the ETX 60 and 70, expect to see a bright (magnitude 9.2) elongated oval with a very, very bright central one-half. There is a very distinct "lump" seen in the ETX 125 and larger scopes exactly SE from the center....this is actually a huge concentration of stars, like a cluster, in one of M 58's spiral arms!
Object 8 - Messier 59 - A Very Small, Starlike Oval Elliptical Galaxy
Look only about one wide field (1 degree) east from Messier 58 and find another elliptical galaxy, only this one if very faint and difficult; it is likely to be missed as a very faint star in the ETX 60 and 70 and perhaps in the ETX 90 as well to an inexperienced observer. This is a tiny elliptical of magnitude 9.6, but its size prevents it from being clearly distinguishable from a star! Curiously, in 1939, a "supernova" was seen in this galaxy at 12th magnitude....an exploding star that almost equaled the brightness of the galaxy itself!
Object 9 - A Bright and Easy Elliptical Galaxy - Messier 60
Messier 60 is a bit larger and thus easier to see with our smaller telescopes; even in the 8" it still appears like a very fuzzy star with no distinctive markings or features. A very faint spiral galaxy, NGC 4647, is found about 3' arc (in the same medium power field) to the NW of M-60, but is only visible in the ETX 125 and LX 90 scopes, and then very difficultly so. Messier 60 is magnitude 8.9, thereby making it an easy target for the ETX 60 and 70 scopes and quite a nice object in the ETX 90 and larger instruments. With a total number of sun more than ONE TRILLION, this is one of the largest of all galaxies known in the Universe....so LOOK at it!
Object 10 - A Large and Very Nice Face-on Spiral Galaxy! Messier 61
From my dark skies of Petit Jean Mountain on May 20, I got stuck on this object....not finding it; both my ETX and LX scopes did just fine on their GO TO's....I got STUCK OBSERVING this magnificent object in near-perfect skies! This face-on galaxy has an incredibly bright nucleus, so bright that you might at first think you are seeing some sort of outburst in the center of this distant galaxy! Look carefully at the photo above taken by the large 120-inch Lick Observatory reflector. The spiral arm at top is CLEARLY visible with the ETX 125 at 125x, as is the huge "knot" just to the right of the center, this also being a spiral arm. These two features are absolutely incredible in the LX 90 at 100x; any more magnification and you begin to lose the spiral structure....any less and you cannot see it at all. The ETX 90 RA showed the top arm and the knot, but not a clearly-defined spiral shape as the larger instruments. In the LX 90, the lower (and left) spiral arm was also clearly visible! This is a very large (5.3' arc) and round object and is clearly visible in the ETX 60 and 70, and actually shows some "graininess" from the alternating dark and bright arms. If you have a smaller telescope and wish to actually "see" a spiral galaxy....this is the one, far easier that Messier 52 (the "Whirlpool galaxy") although the latter is by far brighter. Messier 61 is oddly rated at only magnitude 10.1, although it certainly appears to be brighter.
Objects 11 - Two Galaxies - Messiers 84 and 86 - Both Elliptical Galaxies
Only 17' arc apart, this is an outstanding low-power wide-field sight! M-84 is magnitude 9.3 and M-86 is magnitude 9.7, making them very easy in all scopes, appearing as two large out-of-focus stars at very low power. At medium (about 75x to 100x) magnification, they appear almost IDENTICAL in size and brightness, making for a beautiful sight. Keep in mind which is which! Messier 86 is the one to the east. For the LX 90, there are also two OTHER NGC galaxies (not listed in the concise directory above, as they are too faint for most scopes): ngc4388, a spiral only 16' arc south in a 20mm eyepiece; and ngc4402 only 10' north which is an edge-on spiral in which the dark dust lane CAN be seen at about 150x in the 8" scope.....IF you use your imagination! Otherwise, look for M-84 and M-86 to be two large and bright oval "faint fuzzies" in our telescopes.
Object 12 - Messier 87 - An Incredible Elliptical Galaxy
Examine the 200" Palomar reflector's photograph of Messier 87 shown above.....see all those "larger" spots that appear to be outlying stars of this huge elliptical galaxy? They are NOT stars....those are GLOBULAR CLUSTERS! We obviously cannot see these in any of our telescopes, but it really puts the sizes of these galaxies into perspective. What you CAN see with M-87 is a fantastic galactic core, or "nucleus" that appears just like and 8th or 9th magnitude star right in the center of this uniform glow of 790 BILLION suns. The galaxy itself appears only about 3.2' arc across, but is plainly visible in all of our telescopes at magnitude 9.2; like all the elliptical galaxies we have seen thus far in Virgo, it appears as a large oval glow....only this one has a very distinct nuclear center! This starlike core is clearly visible in the ETX 90, but may be lost even in high magnifications in the ETX 60 and 70.
OBJECT 13 - Messier 89 - A Very Tiny Starlike Elliptical Galaxy
Even at magnitude 9.5 visually, this is a tough galaxy, due principally to its extremely small size of only 1.3' arc diameter. It is unmistakable even in the ETX 60 and 70, but does not show any detail. The LX 90 WILL reveal a very dim nucleus to this large elliptical, this appearing as a star of magnitude 10.5. Of all the galaxies in the Coma-Virgo Cloud, this one may be the closest to Earth.
OBJECT 14 - A Bright Spiral Galaxy - Messier 90
Only about 2 degrees northeast of Messier 87 (above) is found M-90, a very nice spiral tilted greatly toward our line of sight. It measures 7.1 x 2.2' arc in size, so it will appear much elongated. At its center is a stellar point of light, about magnitude 11, so this should be clearly distinguishable in the ETX 90 and larger telescopes. This galaxy, although appearing very small through our telescopes, is actually about the same size and type as our own Milky Way galaxy of some 250 billion suns.
OBJECT 15 - "THE SOMBRERO GALAXY" - Messier 104
Okay, you've waited patiently for this one...but you may be disappointed. The photographs are tantalizing and teasing, and with such contrast you would THINK that some detail should be more visible. However, I also re-visited this galaxy in May 2001 with all the scopes and was a bit surprised. I have view this with wonder in a 40" reflector and with my 24" reflector many times.
The ETX 125 shows a clear dispolarity - the top half being clearly fainter than the bottom half - of M-104. I could NOT see this effect in the ETX 90 RA nor with smaller telescopes. However, the dust lane is barely visible in the 8" scopes, although NOT as clearly as I had remembered in scopes of this size. All in all, the most distinguishable feature is the difference in the two "halves" (see photo above) of this galaxy. Actually Messier 104 is an "added object" to Charles Messier's list....it is one of those I have eluded to in the past that he "should have seen" according to our way of thinking and thus we have included that in his original listing of "faint fuzzies." Messier 104 is seen nearly edge-on with a huge nuclear "bulge" that is clearly seen in the 200" photo above. That much is unmistakable even in the ETX 90 scope. It appears as an elongated blur in the smaller instruments. One very distinguishing feature in the LX 90 that I noticed, however, is the "pointy" ends on each extremity of this galaxy; this was so obvious that it appeared as the points of two sharpened knives. With both the ETX 125 and LX 90 I kept getting the impression that I could imagine further extensions from these "points" than actually exist. This is purely an illusion but I would be interested to hear from others who imagine similarly; I have never had this impression from larger telescopes. Looking at the above photograph, one would think that contrast alone would allow a much clearer and easier view of the huge dark dust lane.....it just isn't so, and it can only be seen with much difficulty, and - like said - is best imagined from the "huge" half section compared to the other side and not so much as a dark lane at all!
OBJECT 16 - YOUR FIRST QUASAR! - Virgo 3C-273
Get set to view perhaps the brightest yet most distant object in the universe....or at least one of them! The Quasi-Stellar Objects , or "Quasars" as they are coined are the most enigmatic of all celestial objects, with distances computed far beyond the most remote galaxies and emanating radiation at a rate more than 100 times the brightest and largest of galaxies.....yet we have no idea what they are. Only a dozen or so are actually known and verified.
To add to the curiosity, these objects are so distant in the visible universe that they appear to be travelling as much as 37 percent of the speed of light!, or about 30,000 miles per second! The one in Virgo, like all the rest, appears nothing more than a very faint star visually. It is about magnitude 12.0, so it is visible in the ETX 90 using a good star chart.
As can be seen in the above chart, 3C-273 appears no more interesting than a very faint star, just on the limit of visibility of the ETX 90 and even the LX 90....but obviously there is more to this object than "meets the eye!" We do know now that this is actually a pair of stars, with at least 90 percent of all the energy we measure from these sources coming from the second, unseen "star." The actual "core" of the energy being emitted comes from something (something??) that is an incredible 7,500 LIGHT YEARS ACROSS! That means a pure energy source the size of a small galaxy! The jury is well out on this one, and likely not to come to a quick verdict. Options include and collapsing galaxy, with the gravitational collapse resulting in the outpouring of energy....perhaps ultra dense stars that have all their masses packed into something so small that you could put it on Long Island.....an "energy lens" shared by groups of hundreds of distant galaxy neighbors.....explosions on our dimensional wall created by black hole collapses in another dimension. Which explanation do YOU like?
At any rate, expect to see only a faint star at this location. Although I have included a starter finder chart here, download http://charts.aavso.org/VIR/3C_273/3C273-B.GIF from the AAVSO and print this chart ("b" chart size) for a more detailed map with good comparison magnitudes. This object is also actually VARIABLE which is why the AAVSO has the chart on it.....varying from magnitude 12.2 to about 13.0. it is not a difficult object to find, and certainly one to provoke much conversation at your next star party....provided that YOU know how to "GO TO" it!
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WANDERING ABOUT....YOUR NEW "USER OBJECT" IN VIRGO
Was there any doubt that I would select our QUASAR 3C-273 in Virgo as our "User Object" for this Virgo Tour? You must have this object on your "quick list" as it amazes people at star parties, cook-outs and casual observing sessions with friends. A word of warning, however....make SURE that you are well-read on the subject before asking your AutoStar to "GO TO" it. Read up on this and the other Quasars in Burnham's Celestial Handbook, volume 3. It is amazing the theories and resources that are available on the subject; likewise, merely use your net search engines on "Quasar" (be prepared for televisions, microwaves, cars, flashlights and auction houses on that one) or better still, "Quasi-Stellar-Object" and see what information is now the most current.
On AutoStar, go to: "Select/Object [enter]...." scroll down to "User Object" [ enter]. Now enter the coordinates given above for "3C-273", using the number keys on AutoStar. After entering the coordinates and pressing "Enter" yet again, scroll down one and you can list the magnitude of the object as "12"[Enter].
So with the addition of a Quasar, you are completing a set which includes a black hole, dark nebulae, curious multiple stars, variable stars and weird deep sky objects. All of these are wonderful for conversation-starters and crowd-stoppers at the big astronomical events!
Next Constellation GO TO" TOUR Installment: LIBRA, the scales. This, like Virgo, appears to be a fairly mundane constellation on the surface, but it is packed with wonderfully rewarding multiple star systems (and a couple of good deep sky objects. So....expect our next "GO TO" TOUR to concentrate very heavily on DOUBLE and MULTIPLE stars, just as our past two have focused on galaxies that you well may never had seen had it not been for your AutoStar and our "GO TO" constellation tours!
Good Observing and explorations of this wonderful world of deep space!
P. Clay Sherrod
Arkansas Sky Observatory
Conway / Petit Jean Mountain
Arkansas
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