Some Light Science Reading. The Constellations: Taurus

As first appeared in the November 2009 edition of the Syracuse Astronomical Society newsletter The Astronomical Chronicle (PDF).

Constellation Map generated with Starry Night Pro 6.

This month's constellation is one of the best in the Night Sky for combining ancient tradition, mythology, modern astronomy, world history, stellar eye candy, and even modern engineering into one reasonably small bordered pen of celestial real estate. The early evening sight of the constellation Taurus the Bull in the November southeast sky at Darling Hill might appear to CNY viewers as a snow divining rod pointing to the western Great Lakes in anticipation of winter and the upcoming lake-effect snow. Taurus is a distinctive constellation and very easy to identify once its central asterism is identified. The brightest star in the constellation is almost equidistant from the easily identified Pleiades and the shoulder of the constellation Orion, the celestial hunter Taurus is running from as the sky appears to move (or, from the most commonly drawn orientation, right towards him!). While Taurus is mildly sparse in quantity when it comes to dark sky objects, it more than makes up for it in quality, hosting two of the most significant stellar sights in the Night Sky.

Like its neighbor Orion, Taurus the Bull is a very, very old constellation and has been recognized as a bull for the duration of its existence in Middle Eastern and European traditions. Earliest records of any kind place the birth of Taurus in the Copper (Chalcolithic) Age (4500 – 3500 B.C.E.), although some records support its existence even earlier. The presence of a bull and what appears to be a Pleiades-like star formation exists on a wall in the Lascaux Caves of France (see right). Although the interpretation of the Constellation set is controversial, this arrangement may date back as far as 16,500 years. Personally, I find even the thought of that kind of continuity between what we might see in the winter skies and what our ancestors also saw at night both comforting and humbling. Many of the same stand-out patterns we know today no doubt stood out immediately to them as the brightest objects in the sky marked out regular places as the Sun set, and the great distance we've traveled in history might be barely perceptible to an ancient astronomer going simply by the positions of stars.

Lascaux Cave bull and star pattern. From the Institute for Interdisciplinary Studies and spacetoday.org.

We begin the tour by aiming our sights at the bright eye of the bull, the star Aldebaran. This orange giant is 44 times the diameter of our own Sun and has already used its hydrogen fuel, leaving this fusion engine to now graze on a steady diet of helium. Its name is derived from the Arabic for "the follower," often reported as in reference to its position below the Pleiades (so "following" this open cluster as we progress into winter). The other stars in Taurus are easy to see in darker skies but not otherwise noteworthy for their brightness at either naked-eye or binocular viewing magnification. Several of the bright stars closest to Aldebaran make up an asterism that a new observer might confuse with the complete constellation. The V-shaped Hyades (center of the image below and shown at right with white border) are composed of five stars, with Aldebaran the brightest tip. I'll admit that the first time I marked out the space for Taurus, I confused this asterism (and lambda-Tau to the west) with the entire object before double-checking the size. No bull. The Hyades star closest to Aldebaran, theta-Tau, is actually a pair of pairs, although they only appear as a single bright pair in binoculars and telescopes.

The Hyades (white) and Pleiades (red). From Lynn Laux, nightskyinfo.com.

Caught within the bull pen is the Pleiades (M45, shown labeled below from a Hubble image). This Tiny Dipper is visible year-round during the daytime in parking lots and slow-moving traffic everywhere (as the object embedded within the emblem on every Subaru, the Japanese name for this asterism) and is one of the treats of winter viewing in CNY (unless VERY early morning viewing is your game or you've been trying to see Mars in the late Summer skies, in which case you've been enjoying the pre-dawn sight of M45 since August). The amount of information available on the Pleiades online and as part of space research could easily (and very likely has) fill an entire book. While the seven bright stars are identified from Greek mythology as the Seven Sisters (Sterope, Merope, Electra, Maia, Taygete, Celaeno, and Alcyone), the counting aid that comes from a pair of binoculars easily reveals nine stars. The two stars that make up the handle of this tiny dipper are the proud parents Atlas and Pleione, placed to the east of the dipper to protect their daughters from either Taurus (for being a bull) or Orion (for being a male). Given the long history of this asterism, it is perhaps not surprising that the parents decided not to stop at seven. In fact, there are over 1,000 distinct stars in the Pleiades that have been revealed as part of multiple high-resolution studies. This density of stars makes the Pleiades a unique open cluster, as there is a wealth of stars and patterns visible at virtually any magnification, from small binoculars to the largest ground-based telescopes. For my first proper viewing session, I spent one full hour simply looking at this cluster through my Nikon 12×50's, amazed at just how little we really see of the Night Sky using the 1×7 binoculars built into our heads (and, perhaps, corrected by horn-rimmed glasses).

The Pleiades in detail. Image from hubblesite.org and wikipedia.org

On the opposite side of Taurus and caught between the horns is the first of the categorized Messier objects, the Crab Nebula. M1 to its friends, this nebula is a supernova remnant with a remarkable history. As documented in both Arab and Chinese texts (Europe was just coming out its, er, Dark Ages at the time), this supernova was so bright on July 4, 1054 that it was visible during daylight hours (and, as you can guess by the date, visible without any magnification). The supernova remnant we know today as the Crab Nebula was discovered (and correlated to the original supernova) first by John Bevis in 1731, then by Charles Messier in 1758 while, as it happens, observing a comet (that Messier is known best for his catalogue of objects that were NOT comets instead of the comets he worked so diligently to discover is one of the great fun ironies of astronomy). The NASA images of the Crab Nebula reveal a dense sponge-like structure full of filaments of all sizes. The image above shows a remarkable sight – the full cycle of the pulsar at the heart of the crab that continues to magnetically drive the expansion of the nebula (in the series of frames, the pulsar lies below and to the right of a constant-brightness star).

The Crab Nebula pulsar. Image from www.strw.leidenuniv.nl

Stepping forward several hundred years, Taurus also marks the present locations of Pioneer 10 and COSMOS 1844. Pioneer 10 is currently speeding in the direction of Aldebaran, having been successfully steered through the asteroid belt to make a series of images of Jupiter. At its current velocity, this trip to Aldebaran's current location would take 2 million years, about the same amount of time it might take most of the world to decipher the meaning of the emblematic plaque attached to its exterior (below). Perhaps someday we'll have to explain to the aliens how a civilization that could launch a complicated probe into space couldn't see the multitude of planets in their own Solar System, then perhaps have to explain what happened to Pluto hat it no longer appears in our Solar System images. COSMOS 1844 is one of over 2440 satellites launched by the Soviet Union (and now Russia) since the first of the COSMOS series in 1962. At mag. 5, this satellite makes for a fun artificial viewing target (with a good map in hand).

The Pioneer 10 plaque. From wikipedia.org.

The final sights for telescope viewers include four NGC objects. NGC 1746, 1647, and 1807 are open clusters with magnitudes between 6 and 7. NGC 1514 (below) is a mag 10 planetary nebula just at the far edge of the Taurus border that should be increasingly good viewing as Taurus works its way towards our zenith (1514 will be the closest it will get to our zenith by midnight, a perfect last-good-look before Darling Hill completely freezes over).

NGC 1514. From Martin Germano, seds.org)

Phenomenal viewing at a reasonably safe distance. Just be mindful not to wave your red flashlights at Aldebaran!

www.syracuse-astro.org
http://en.wikipedia.org/wiki/Taurus_%28constellation%29
http://en.wikipedia.org/wiki/Divining_rod
http://en.wikipedia.org/wiki/Great_Lakes
http://en.wikipedia.org/wiki/Lake_effect_snow
http://en.wikipedia.org/wiki/Orion_%28constellation%29
http://en.wikipedia.org/wiki/Chalcolithic
http://en.wikipedia.org/wiki/Lascaux_Caves
www.spacetoday.org/SolSys/Earth/OldStarCharts.html
http://en.wikipedia.org/wiki/Aldebaran
http://en.wikipedia.org/wiki/Hyades_%28star_cluster%29
http://www.nightskyinfo.com/archive/hyades/
http://en.wikipedia.org/wiki/Pleiades_%28star_cluster%29
http://www.subaru.com/
http://en.wikipedia.org/wiki/Mars
http://en.wikipedia.org/wiki/Sterope_(Pleiad)
http://en.wikipedia.org/wiki/Merope
http://en.wikipedia.org/wiki/Electra_(Pleiad)
http://en.wikipedia.org/wiki/Maia_(mythology)
http://en.wikipedia.org/wiki/Taygete
http://en.wikipedia.org/wiki/Celaeno
http://en.wikipedia.org/wiki/Alcyone_(star)
http://en.wikipedia.org/wiki/Atlas_(mythology)
http://en.wikipedia.org/wiki/Pleione_(mythology)
http://en.wikipedia.org/wiki/Crab_Nebula
http://en.wikipedia.org/wiki/Dark_Ages
http://en.wikipedia.org/wiki/John_Bevis
http://en.wikipedia.org/wiki/Charles_Messier
http://www.nasa.gov
http://www.strw.leidenuniv.nl/~oberg/Pulsars/external.html
http://en.wikipedia.org/wiki/Pioneer_10
http://en.wikipedia.org/wiki/Jupiter
http://en.wikipedia.org/wiki/Pluto
http://en.wikipedia.org/wiki/Cosmos_%28satellite%29
http://en.wikipedia.org/wiki/Pioneer_plaque
http://server1.wikisky.org/starview?object_type=4&object_id=241&object_name=NGC+1746&locale=EN
http://server1.wikisky.org/starview?object_type=4&object_id=211&object_name=NGC+1647&locale=EN
http://server1.wikisky.org/starview?object_type=4&object_id=279&object_name=NGC+1807&locale=EN
http://seds.org/~spider/ngc/ngc.cgi?NGC1514

Syracuse Astronomical Society President's Message For March, 2009 – The Messier Marathon Edition

A repost of the original at the Syracuse Astronomical Society website with a brief overview of our upcoming (weather-permitting) Messier Marathon.

Greetings Fellow Astrophiles!

This newsletter comes to you after a short run within the last ten days of almost perfect viewing conditions (ignoring the cold, of course, with the Vesper air reaching the high teens for long durations on a few occasions). We are now officially entering the SAS viewing season, with scheduled New Moon Public Viewing sessions until November (we will see how that plays out) and, we hope, many dark, clear nights in between.

The First Few "Unofficial" 2009 Sessions

The beginning of the viewing year at Darling Hill began this past March 13th, with Observatory Directory Ray Dague and I braving the Vesper elevation and residual ice at the driveway base to check the location and attempt some viewing on what turned out to be a crystal clear night. Despite all efforts (including an outside climb and feet-on-walls pulling. We undertook quite the comical effort just to put eyepieces in), the frozen Observatory roof decided it was too early to "officially" open. We settled for trusty binoculars, plenty of power for Messier warm-up searches and, high above in Gemini, Comet Lulin (which we had to double-check was not NGC 2420).

Board members frozen as stiff as boards.
From left: J. McMahon, J. Funk, D. Allis, G. Sigworth. Photo by Raymond Dague.

Additional viewing sessions/board meetings (such as the one captured above on March 20th) were just as clear and just as busy (but included an open Observatory roof!), due in no small part to just how infrequently we in CNY are able to make it outside during the winter for any viewing sessions because of both the cold above and, in the case of Darling Hill, driveway accessibility. For those who wanted to keep track, last year had nine scheduled public viewing sessions and only THREE that were clear enough to be productive. We are already well on our way to a record year and only hope that the gas prices remain low to keep the continual driving to Tully as inexpensive as possible. And, speaking of records…

Messier Marathon

Our early April 2008 Messier Marathon at Darling Hill was a complete overcast wash, with two hours of patience revealing three stars (we used the time to talk about gear, which itself is never a bad thing). It would be difficult to imagine a worse situation that didn't include precipitation. With cautious optimism for the weekend, we now print out check lists and list object pages in our favorite star charts for MM-2009.

A Brief Overview

We are often visited at the Hill by people who may have heard of the "Mn" designation for an object in the Night Sky but do not know specifically what it refers to. If you're learning about Messier objects in the context of a website post about the Marathon, then you may think the Marathon to be some kind of celestial relay race between fuzzy patches. Briefly, here are the 5 W-H's about Messier and the Marathon.

Courtesy Thierry Lombry, www.astrosurf.com/lombry.

Who: The marathon owes its existence to Charles Messier who, by all accounts (and to the best of my google efforts), never engaged in what he would have simply referred to as "The Me Marathon." Messier was a famed French comet hunter (the search for comets in the 17th and 18th centuries was THE original "Space Race," as such discoveries were sure to bring fame and prestige) who, with his assistant Pierre Méchain, catalogued what we know today as the Messier Objects specifically because he wanted to avoid these confusing objects in his cometary searches. Yes, the man who dedicated his life to finding comets is now best known for the catalogue of non-comets he generated. C'est la vie.

What: The Messier Objects are simply a collection of clusters, nebulae, and galaxies that are visible through binoculars and low-power telescopes (and some are naked-eye objects). In effect, they are a collection of the "closest of the bright objects" that one might confuse with a comet, with the "closest/brightest" set including clusters and nebulae within the Milky Way and many galaxies far beyond our spiral arms. As massive, distant, and bright objects, they are stationary in the sky, making them easy for Messier to catalogue in his comet hunting efforts and, for us, making them useful guide posts both for their identification from Constellation markers and for the identification of far fainter objects based on proximity. There are 110 counted Messier Objects but, according to Pierre Méchain himself, only 109 actual objects, as M101 and M102 (the Pinwheel Galaxy) are the result of double-counting (on the bright side, when you've found it once, you've found it twice!). While the majority of the list goes back to Messier's time, the last object added, M110, was included in 1960.

Charles Messier (1730 – 1817). Click HERE for more info.

Covering the second important "what," the Messier Marathon is simply a fun way to see how well you know the "photons in your neighborhood… the ones you don't know you see each night."

Where: Up! Well, more specifically, up in the Northern Hemisphere. As a French astronomer, Messier's catalogue contains only objects observable from his Observatory. Accordingly, all 110 objects are visible from Northern Latitudes. That means that (1) a multitude of objects in the Southern Hemisphere that WOULD have made the Messier list are not included because he simply could not point his scope into the ground to look at them and (2) those in the Southern Hemisphere do not engage in Messier Marathons as much as they engage in Messier Sprints, as they have fewer objects to identify (and, the further South they are, the shorter their list is).

The Pinwheel Galaxy (M101 – 102)

When: Members of the Messier list grace our skies all year, with nearly every Constellation visible in the Northern Hemisphere hosting at least one object. Only two things in the Night Sky can obscure Messier objects. The first of these is "whatever else you want to see" that keeps you from looking for the Messiers. The second is the Moon, which can, in fact, obscure the Messier objects considerably (those that are naked-eye Messiers then require binoculars to see, those that are binocular Messiers then require either patience or higher power).

There is one reasonably broad "sweet spot" in the calendar year during which it is POSSIBLE to see every Messier object, with the rotation of the Earth responsible for bringing the entire list to your tripod. This is, of course, only possible because clouds, the irregularity of the horizon (such as our trees to the South and Syracuse to our North), and your ability to remain awake all factor considerably in your success. This time of year is mid-March through early April.

Why: For the reason for the catalogue, see the "What." For the reason for the Marathon, well, why not? Despite some criticism of the Marathon you can find online, the Marathon provides a way for amateur astronomers to test their memorization of positions in the Night Sky and, important to those of us in CNY, pull out our optics and dust off our notebooks after two or three winter months of missed practice. Again, the Messiers are not simply a set of goals for an observing session, they are invaluable tools as guide posts for the identification of other objects. If the Constellations are "feet" in an astronomical ruler, their associated stars and the nearby Messier Objects serve as the "inches."

How: An experienced Messier hunter can find the complete set of objects in a pair of 10×50 binoculars. As the goal to some Marathoners is "quantity, not quality," a low-power pair of binoculars are best for both speed and movement (although your neck will begin to object to objects at your zenith). If I may sneak in a "tortoise and hare" comparison, there's nothing wrong with finding 20 objects and enjoying the view. You have ALL YEAR to complete your Marathon. They're not going anywhere!

For the CNY SAS Members: If your goal is to spend from 8:00 pm to midnight outside, your best luck with Messier hunting by binoculars (that is, listing objects that will result in the least amount of neck fatigue) will find you pointing to the south to Orion (M42, M43, M78), Taurus (home of the naked-eye Pleiades, M45, and the Crab Nebula, M1), Canis Major (home of Sirius, the brightest star in the night sky, and M41), Puppis (just to the left of Canis Major and home to M46, M47, M93), and Leo (far to your Southeast, home of M65, M66, and M96).

The North provides a plethora of objects as well, but the glow from Syracuse makes observing a bit more problematic. The Andromeda Galaxy and its Messier companions (M31, M32, M110) in Cassiopeia and the Dumbell Nebula (M76) and Triangulum Galaxy (M33) in Triangulum disappear quite quickly from view after 8:00 pm behind our high northwest tree line, so come early if you want to see them! Waiting out the tree line to our northeast (after about 9:30 pm), Ursa Major and Canes Venatici mark the locations of (from west to east) M82, M81, M108, M97, M109, M40, M106, M101, M51, M63, M94, and M3. As you can see, with limited fatigue on your neck in a pair of handheld binoculars, you can do a considerable amount of checking-off of the Messier objects in very short order and still go to sleep on schedule. I will have my trusty 6" Newtonian "Stu-Special" in tow, and I'm sure several others will have scopes to complement the Observatory Cave if the weather holds out. Online lists and sky charts abound, but I assume any astronomy book you have will contain sky charts and Messier locations. Don't forget a red flashlight.

For those who missed them the first time, you might have a chance to see the Andromeda galaxy and her companions again before 6:30 am. For the hardcore observers, you might even be able to cross them off your list twice, although the tree line to our northeast will likely make it quite difficult. We may have to move the party to higher ground!

For more info on the Marathon and Viewing Tips, see www.avastronomyclub.org/observing/messier/marathon_tips.htm and www.robhawley.net/mm/, or simply google "Messier Marathon."

Space is the place,
Damian Allis, Ph.D.
sas@somewhereville.com

Links Used Above (Subject To Web Changes)

en.wikipedia.org/wiki/New_Moon
www.daguelaw.com
en.wikipedia.org/wiki/Gemini_(constellation)
en.wikipedia.org/wiki/C/2007_N3
seds.org/~spider/ngc/ngc.cgi?2420
en.wikipedia.org/wiki/Tully_(town),_New_York
seds.lpl.arizona.edu/messier/Xtra/marathon/marathon.html
en.wikipedia.org/wiki/Messier_marathon
en.wikipedia.org/wiki/Charles_Messier
en.wikipedia.org/wiki/Pierre_Mechain
en.wikipedia.org/wiki/Messier_object
en.wikipedia.org/wiki/Binoculars
en.wikipedia.org/wiki/Telescopes
en.wikipedia.org/wiki/Milky_Way
en.wikipedia.org/wiki/Constellation
en.wikipedia.org/wiki/Messier_110
en.wikipedia.org/wiki/Northern_hemisphere
en.wikipedia.org/wiki/Southern_Hemisphere
en.wikipedia.org/wiki/Moon
en.wikipedia.org/wiki/Messier_marathon#Criticism_of_Messier_Marathons
en.wikipedia.org/wiki/Zenith
www.syracuse.ny.us
www.skymaps.com/downloads.html
www.avastronomyclub.org/observing/messier/marathon_tips.htm
www.robhawley.net/mm