Some Light Science Reading. The Constellations: Camelopardalis

As first appeared in the June 2012 edition of the Syracuse Astronomical Society newsletter The Astronomical Chronicle.


Image generated with Starry Night Pro 6.

We continue our presentation of CNY circumpolar constellations with a relative newcomer to the great list of 88 constellations (in Western Culture, anyway). Camelopardalis the Giraffe is lucky to be identified as a constellation at all, as neither the Greeks nor the Romans saw this part of the sky as interesting enough to, dare I say, stick their necks out and define the stars here as anything of importance. Its Western history dates to approximately 1612, when the famed Dutch astronomer and cartographer Petrus Plancius (who also provided us with Monoceros, another recent constellation in the Northern Hemisphere) grouped the stars with the name Camelopardalis which, loosely translated, breaks down into “camel” and “leopard,” the combinations of “long neck” and “spots” being a reasonable first approximation to the features of an animal most of Europe had likely never seen at the time. The Chinese and Indian astronomers, on the other hand, were far more meticulous in their use and definition of stars in the Night Sky and the brighter stars in Camelopardalis are all defined in one asterism or another. The positions are obviously the same, but the history and mythology of the stars in Camelopardalis are markedly different.

Referring back to the main image in my first article on circumpolar constellations (Ursa Minor, Jan/Feb/Mar 2012, above), that vast majority of Camelopardalis lies above the Northern Horizon, with its head region tightly packed between the boundaries of Draco and Ursa Minor. I’ve seen several stick figure representations of Camelopardalis that attempt to depict only the legs (from the brightest stars in the constellation), only the legs and torso (by cutting Camelopardalis off at the knees and connecting these two starts to make a body), only the legs and half the neck (using bright stars again), the legs and full neck (getting a head in there as well), and the full-on head-neck-torso-short-leg variation that looks most like a giraffe but, likely, deviates most from classical definitions. The correct line drawing for you is, of course, the one that helps you identify the constellation easiest.

During the June mid-evenings, Camelopardalis is oriented with its feet standing firmly on the Northern Horizon (perhaps with its legs obscured behind tall trees that serve as celestial underbrush during our observing sessions). With no star brighter than 4th magnitude and most in the 4th to 5th range, one does have to work a bit harder than usual to mark out the legs and torso of Camelopardalis from Darling Hill, as the electromagnetic diaspora emanating from Syracuse consumes an ever-increasing expanse of the Northern Sky (a solution, then, is to simply observe from somewhere comfortably North of Syracuse!). As you check for the neck, consider the head of Camelopardalis reaching for the bowl of the Big Dipper. The brightest star near where the head would be, the appropriately named “HIP47193,” will sit just to the left of Polaris for your early-night June observing.

Neither the Greeks, nor the Romans, nor most any Western Culture, nor Charles Messier or his assistant Pierre Méchain found anything of importance to amateur astronomers among the stars we know as Camelopardalis. It took until the 18th century for William Herschel to identify an object worthy of cataloguing in the forms of the sort-of elliptical/sort-of spiral galaxy NGC 2403 (shown above, from Hubble). We now know that this region of the sky contains many interesting, but faint, observables, some of which lie within the Milky Way (such as the planetary nebula NGC 1501 and the open cluster NGC 1502) and many which lie far, far beyond, all likely visible only because they lie away from the galactic plane of the Milky Way (and, therefore, are identifiable because they are in a relatively barren stellar savannah that doesn’t obscure our view). Among these are NGC 2655, IC 342 (shown below in infrared from NASA WISE), and NGC 1569 (all exceptionally tough targets due to Syracuse light pollution).

– Happy Hunting, Damian

Some Light Science Reading. The Constellations: Canes Venatici

As first appeared in the March 2010 edition of the Syracuse Astronomical Society newsletter The Astronomical Chronicle (PDF).

Constellation Map generated with Starry Night Pro 6.

It often seems to me that the night is much more alive and richly colored than the day.
Vincent van Gogh to his brother Theo, 1888

If the Hubble Ultra Deep Field image has taught us nothing else, it is that every piece of the sky, regardless of how diminutive it may be in the two-dimensional view of the universe through our eyes, holds a wealth of astronomical treasures.  We begin the 2010 Constellation presentations with one such small, but by no means insignificant, piece of the sky.  Canes Venatici (“Now that’s Italian(-sounding)!”) is a young constellation, one of the many additions formalized by Johannes Hevelius in the 17th century and the result of some rather troublesome bookkeeping over the course of written history.  As the story goes, several of the stars within the modern borders of Canes Venatici were originally part of Boötes‘ staff (or club.  Some herdsmen take the protection aspect of their job very seriously).  A poor translation of Ptolemy‘s Almagest from Greek to Arabic to Latin resulted in the “hook” of the staff being turned into “dogs” (accordingly to the translation history provided at wikipedia, the translation went from “the spearshaft having a hook” in Arabic to “spearshaft having dogs” in Latin.  Perhaps the Arabic-to-Latin translation occurred on a late Friday afternoon before a much-anticipated Public Viewing session?). Befitting a new constellation of hunting dogs now accompanying Boötes in his nighttime watch, Hevelius, er, ran with it and gave the mythological canines Chara and Asterion a small but astronomically busy place next to their master.

The two dogs Chara (represented by the star “Chara”) and Asterion (represented by “Cor Caroli”) are identified by only their two brightest stars, which are themselves joined by a short leash in the modern line representation.  The many dimmer stars in this constellation that jump out even with low-power binoculars add multiple “spots” to the imagined bodies of these two dogs.  As they rush ahead of their master Boötes, they point straight towards the hindmost of Ursa Major (or appear to be running past the Big Dipper).  If celestial real estate is any measure of actual size in the ancient illustrations, the giant Ursa Major is right in aligning his gaze away from the two diminutive playful pups.  I’m sure there’s some imagined connection between Canes Venatici and its final bordering constellation Coma Berenices, but I was once told that the explanation can get a little hairy (if you did not recognize that as a poor pun, do read the wikipedia entry for Coma Berenices, which may find its way to a feature in upcoming newsletters).

If we let lying dogs rest for a moment, we find Chara and Asterion in possession of five Messier Objects, including a phenomenal telescope sight that is otherwise most often found by chasing Ursa Major’s tail.  The distance between M3 and M106 marks the total width of this constellation.  M3 (below) is an 8 billion-year-old globular cluster composed of 500,000 stars that rests roughly 1/3 the width of our galaxy from us (33,900 light years).


M3, from Robert J. Vanderbei.

M106 (below, from NASA/CXC/University of Maryland) is one of those distant (well, 25 million light years) galaxies that NASA astronomers have a field day with as they overlay various wavelengths to make visually stunning images.  The strong X-ray lines in its spectrum indicate that a supermassive black hole resides in this galaxy that is in the process of devouring large swaths of stellar and gaseous matter.


M106, from NASA/CXC/University of Maryland.

M94 (below), also known as the Cat’s Eye Galaxy, is a remarkable structure, as it contains two distinct spiral regions in one galaxy (providing the bright central pupil and the darker edges of the eye).  Speaking of two significant features in one, its discovery is attributed to Pierre Mechain and its cataloging by Charles Messier, occurring just two days later (pairs come in three’s?).  M94 is itself the most prominent member of the so-called M94 Group of Galaxies, a closely associated group of (up-to 24) galaxies within the much larger Virgo Supercluster.  Fourteen of these galaxies lie between 9.0 (M94) and 14.2 magnitude, making the search possible with available gear but only under most ideal viewing conditions.


M94, from Spitzer, GALEX and R. Jay GaBany.

The Sunflower Galaxy (M63, below) was one of the first galaxies to have a distinctive spiral quality associated with it (this by Lord Rosse in the mid-19th century).  The short and tightly spiraled arms pack considerable spectral density into a seemingly small space, providing the stem-free sunflower view that, as it contains tens of thousands of suns, might better be called The Galaxyflower.  M63 is a member of the M51 Group, another cluster of galaxies within the Virgo Supercluster that feature, as their crown jewel…


M63, from NASA and WikiSky.

The Whirlpool Galaxy (M51, below) is, perhaps, the third best view of any galaxy to be found at Darling Hill (the second-best being the Andromeda Galaxy (M31) and the first being, you guessed it, our own Milky Way).  We view the Pinwheel Galaxy looking straight down the rotation axis of the pinwheel, providing us with what can be a very clear view of the spiral structure of the galaxy through our scopes (and providing those with big scopes a very clear view of this structure).  I suspect not a single member with a non-GOTO scope has ever said “It’s over in Canes Venatici.”  Instead, I suspect the standard manner of location involves some instruction stating “Look at the last star in the handle of the Big Dipper and go at a right angle about half the distance of the last two stars in the handle.”  If you can see the famous pair Alcor and Mizar in the Big Dipper, you’re almost at M51 in a pair of binoculars.  The bright bulge at the end of one spiral arm is a true companion galaxy.  Computer models indicate that the distortions of the M51 arm at this companion position are a result of the companion galaxy passing through the plane of the M51 some 550 million years ago, as if M51 were in the process of throwing its companion out into the void to be retrieved by our two dogs.


M51, from NASA and ESA.

Lord Rosse, who also identified the spiral structure in M63, observed and sketched the clear spiral structure of M51 in 1845 (shown below).  The sketch he made reminds me of the center swirl within Vincent Van Gogh’s “Starry Night” (shown below).  And speaking of fine art, the Hubble image of M51 (provided as a massive download here) is one of those views that might well make the final cut in the first intergalactic exhibition.

The proverbial “Cat’s Meow” of nighttime viewing from a small pair of stars that mark a small pair of dogs that were spared from the celestial kennel thanks to a mistranslated description of a cudgel.

Clear skies, Damian

www.syracuse-astro.org
www.starrynight.com
en.wikipedia.org/wiki/Vincent_van_Gogh
en.wikipedia.org/wiki/Hubble_Ultra_Deep_Field
en.wikipedia.org/wiki/Universe
en.wikipedia.org/wiki/Canes_Venatici
en.wikipedia.org/wiki/Johannes_Hevelius
en.wikipedia.org/wiki/Bo%C3%B6tes
en.wikipedia.org/wiki/Ptolemy
en.wikipedia.org/wiki/Almagest
en.wikipedia.org/wiki/Canes_Venatici#History
en.wikipedia.org/wiki/Ursa_Major
en.wikipedia.org/wiki/Coma_Berenices
en.wikipedia.org/wiki/Charles_Messier
en.wikipedia.org/wiki/Messier_3
www.princeton.edu/~rvdb/images/NJP/m3.html
en.wikipedia.org/wiki/Messier_106
en.wikipedia.org/wiki/X-ray
en.wikipedia.org/wiki/Supermassive_black_hole
en.wikipedia.org/wiki/Messier_106
gallery.spitzer.caltech.edu/Imagegallery/image.php?image_name=ssc2007-06a
en.wikipedia.org/wiki/M94
en.wikipedia.org/wiki/Pierre_Mechain
en.wikipedia.org/wiki/M94_Group
en.wikipedia.org/wiki/Virgo_Supercluster
ssc.spitzer.caltech.edu/legacy
galexgi.gsfc.nasa.gov/docs/galex/surveys/NGS.html
www.cosmotography.com/index.html
en.wikipedia.org/wiki/Messier_63
en.wikipedia.org/wiki/Lord_Rosse
en.wikipedia.org/wiki/M51_Group
en.wikipedia.org/wiki/Messier_63
en.wikipedia.org/wiki/NASA
en.wikipedia.org/wiki/WikiSky
en.wikipedia.org/wiki/Whirlpool_Galaxy
en.wikipedia.org/wiki/Andromeda_Galaxy
en.wikipedia.org/wiki/Milky_Way
en.wikipedia.org/wiki/Mizar_%28star%29
en.wikipedia.org/wiki/Whirlpool_Galaxy
en.wikipedia.org/wiki/European_Space_Agency
en.wikipedia.org/wiki/Starry_Night

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