MARCH 2011 VIEWING LIST

ObjectTypeSizeDistanceCoordinates

14” Scopes

M76*PN3’ 3400 LY 01h 42’ +51 34’

M42*EM/RN 1.5 1600 LY 05h 35’ -05 27’

M1*SR 6’ 6300 LY 05h 35’ +22 01’

Abell 21**PN 12’ 1000 LY? 07h 29’ +13 15’

NGC 2392*PN 40” 3000 LY 07h 29’ +20 55’

M46/NGC2438*OC/PN 28’ 5400 LY 07h 42’ -14 49’

M81*Gal 21’ 12,000,000 LY 09h 56’ +69 04’

M82* Gal 9’ 12,000,000 LY 09h 56’ +69 41’

NGC 3115**Gal7’ 22,000,000 LY 10h 05’ -07 43’

NGC 4236**Gal 18 11,700,000 LY 12h 17’ +69 28’

4” Refractor

M37OC24’ 4400 LY 05h 52’ +32 33’

M35OC28’ 2800 LY 06h 09’ +24 20’

UU AurigaeCarbon star - 1800 LY 06h 36’ +38 27’

M41OC38’ 2300 LY 06h 47’ - 20 45’

Alpha Geminorum “ - 52 LY 07h 35’ +31 53’

Abbreviations:

MS = Multiple Star, EN = Emission Nebula, RN = Reflection Nebula, Gal = Galaxy, GC = Globular Cluster, LY = Light Year, OC = Open cluster, PN = Planetary Nebula, SR = Supernova Remnant,

CS = Carbon Star, * = Video imaging optional, ** = Video imaging recommended

MARCH 2011 OBJECT DESCRIPTIONS

M76 in the constellation Perseus (PURR-see-us) is commonly known as the Butterfly or the Little Dumbbell Nebula. It is a standard planetary nebula with a 16th magnitude central star. The unusual appearance is due to the angle of the nebular ring that is expanding outward from the white dwarf at about 42 K/sec. Most of the visible light is emitted in the OIII doubly ionized Oxygen band so the use of a nebula or OIII filter will enhance the image.

M42 in the constellation Orion (oh-RYE-un) is the brightest diffuse nebula in the sky. Known as the Great Orion Star Factory, this combined emission/reflection nebula has been found to harbor scores of newly forming stars. Use low magnification, with and without a nebula or OIII nebular filter, for the extensive nebular structure, and higher magnification to detect the Trapezium, a cluster of bright young stars in the central portion of the cloud.

M1 The Crab Nebula in the constellation Taurus (TAW-rus) is the brightest and most famous supernova remnant in the sky. The expanding gas cloud is the result of an exploding star observed in 1054 A.D. At it’s brightest it was four times brighter than Venus and was a visible daylight object for 23 days. The gaseous shell is about 10 light years in diameter and is still expanding outward at the high rate of 1800 kilometers per second. Best view can be had with a 22mm eyepiece with the Broadband filter attached.

Abell 21 is a planetary nebula in the constellation Gemini (GEM-in-eye). Commonly known as the Medusa Nebula, this crescent-shaped,10th magnitude object is the remnant of the dying gasps of a G-type star such as our own Sun. Fairly bright, it may be faintly seen either through the 4” with an OIII filter, or fairly reliably through the 14” scopes. Distance estimates vary widely, from 1000 to 5600 light years. To observe this object you must manually enter the coordinates.

NGC 2392 is a planetary nebula in the constellation Gemini (GEM-in-eye). Discovered by William Herschel in 1787, it is widely known as the Eskimo Nebula. Through the 14” scopes you will see an 8th magnitude star surrounded by a faint 10th magnitude nebulosity. On exceptional nights the nebula displays an intense blue/green glow. The central star is a white dwarf about 40 times brighter than our sun. The planetary has a diameter of about 6/10 of a light year. This is a good candidate for either the Broadband or the OIII filter for visual observing in order to accentuate the nebulosity.

M46 is an open cluster in the constellation Puppis (PUP-iss). It is composed of approximately 150 stars of 13th magnitude or brighter within it’s 30 light year diameter. The cluster is estimated to be about 300 million years old. Superimposed upon the cluster is a faint Planetary Nebula, NGC 2438, which is about 2900 light years away. From the difference in object distances it is obvious that the two objects are not associated, but merely in the same line of sight. If the faint nebula is not easily seen, try using a Broadband or OIII filter and slightly higher magnification to sort it out from the surrounding stars.

Note: The duo of galaxies below is fairly bright and is best viewed as a pair. Use the maximum magnification that will show both in the same field of view. Try using the 4” and either the 22mm or the 31mm to observe the pair. These galaxies warrant much more than a brief peek. Spend some time on them and you may be surprised at the detail that may be gleaned from the faint light.

M81 is a spiral galaxy of 6.8 magnitude in the constellation Ursa Major (URR-suh-MAY-jer). Seen nearly face-on, it resides 12 million Light Years away. Over 70 globular clusters have been discovered orbiting this galaxy. M81 and adjoining galaxy M82 had a close encounter about 600 million years ago, resulting in a prolonged period of intense new star formation that continues today. This is a prime candidate for the east scope.

M82is an irregular galaxy of 8th magnitude in the constellation Ursa Major (URR-suh-MAY-jer). Also known as the Cigar Galaxy for it’s elongated shape, M82 is also about 12 million Light Years distant. The close encounter with M81 described above distorted the shape of this irregular galaxy, creating many bright, turbulent star-forming regions. Over 100 globular clusters have been observed orbiting this galaxy.

NGC 3115, common known as The Spindle, is a type S0 lenticular galaxy glowing at nearly 9th magnitude. Floating in the dim constellation Sextans (SEX-tanz), it was discovered by Wm. Herschel in 1787. The thin disk is inclined about 24 from edge-on and has a diameter of about 40,000 light years. Compare this to the 100,000 light year diameter of our own Milky Way. An interesting fact is that, while NGC 3115 has an estimated mass of only 7 billion suns, the Hubble Telescope has proven the existence of a 2 billion sun black hole in the central core. Once again, compare that to the 100+ billion sun mass of the Milky Way with its 4.2 million sun black hole. There is much more to The Spindle than meets the observer’s eye.

NGC 4236 is a barred spiral galaxy in the constellation Draco (DRAY-co). Located about 11.7 million light years away, it has a listed magnitude of 9.6. This seems bright enough to be an easy target to spot, but there is a problem. With an apparent size of over 18 arc minutes (The Moon is about 30 arc minutes across) the light is spread over a fairly large patch of sky. While this object is considered a faint target for scopes of 100mm aperture, I’ve had little luck with our 4” refractor. Since NGC 4236 is a so-called starburst galaxy, the light is unevenly spread along the major axis and appears clumpy through larger scopes..

M37 in the constellation Auriga (awe-RYE-gah) is a rich open cluster with an apparent diameter of about 24 moa. It is about 27 light years in diameter. In the 4” refractor you should be able to count more than 150 stars. This is one of the finest open clusters in the sky when viewed through a small scope. Best view is through the 31mm eyepiece on the 14” or the 22mm eyepiece through the 4” scope.

M35 in the constellation Gemini (GEM-in-eye) is a large, well-populated open cluster with a diameter of 30 light years. It has over 120 stars above 13th magnitude. The cluster is about 110 to 150 million years old. About 15 arc minutes away lies a densely packed open cluster, NGC 2158, that looks more like a globular cluster. This dim apparent companion is actually much farther away at about 16,000 light years.

UU Aurigae in the constellation Auriga (awe-RYE-gah) is a carbon star with a variable light output. At an average magnitude of 5, this star stands out to observers due to its notable reddish-orange tint. The color derives from carbon dust in the star’s relatively cool upper atmosphere. Locate it by keying in the celestial coordinates. It is worth the extra work.

M41 in constellation Canis Major (KAY-niss MAY-jer) is an open cluster slightly larger in apparent diameter than the full moon. Shining at about 5th magnitude, this is a fine object for small telescopes Look for the reddish star shining at 7th magnitude in the center of the cluster. Use the 4” with the 22mm eyepiece for a contrasty view.

Alpha Geminorum commonly known as the star Castor in the constellation Gemini (GEM-in-eye) is a fascinating triple star with a secret. Each of the stars in this triple system is itself a spectroscopic double star. So when we gaze at Castor we are in fact looking at a six star system. Star A (Magnitude 1.9) and star B (mag. 3.0) orbit each other every 467 years. Distant star C is a faint 9th magnitude companion that orbits the A & B pair in a yet-to-be-determined orbital period. While the optical pair, Castor and Pollux ( Alpha & Beta Geminorum) are visually associated in the sky, they are not physically associated in any way, being many light years apart.

Forrest Lockhart