Some Light Science Reading. The Constellations: Triangulum

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

Constellation Map generated with Starry Night Pro 6.

I remember my first foray into Constellation memorization, still the first thing I recommend for anyone beginning in amateur astronomy (primarily for using these imagined creations to memorize the locations of far dimmer objects when you graduate up to binoculars or small scopes, but also simply to develop a sense of, well, the space between these creations as you jump between objects).

Orion, yeah yeah… Scorpius, O.K. obvious… The body of Sagittarius looks like a teapot, that’s not bad… Cassiopeia is the great big “W” Jonathan Winters discovered in “It’s a Mad … Mad World“… The “Dippers” are dippers… Canis Minor is composed of two stars, and they happen to be in a straight line! At least it contains a bit of animal lore and the great Procyon. That should be easy to find.

Ah! Triangulum. A famed triangle of stars. Named after the famed shape called “The Triangle,” and believed to be the last Constellation drawn out by Ptolemy as one of the original 48 Constellations of Antiquity. It bet it was supposed to be “The Great Northern Spearhead,” but Ptolemy must have been a pacifist. It is believed he committed it to papyrus at 4:50 p.m. on a Friday before the scribes began copying the first edition Monday morning.

I have to admit, this Constellation seemed like an odd member of the original series, if for no other reason than the seemingly minimal amount of work (or so I thought) that must have gone into its creation. As I hope to convey to you in the next few paragraphs, this little Constellation has stood the test of time for a few good reasons.

To begin, the heart of Triangulum dates back all the way to the Babylonians (which means it likely also dates back further into pre-recorded history) who, with the inclusion of what we now know as γ-Andromeda, called this Constellation MUL.APIN, or “The Plough.” With this simple extension added in red in the image above, I hope the resemblance is now obvious. To my technologically-biased mind, the nondescript triangle of the modern sky instantaneously becomes the (seemingly) everlasting testament to the power of agriculture and the shining reminder to all of the simple tool responsible for the creation of a commodity we know today as “surplus.” I don’t think that’s going too overboard in the description.

You are here.

We have these “organic farming” discussions where people ask you “Where do you think your food comes from?” It has been quite a recent phenomenon in the long history of this little sphere Carl Sagan referred to as a “Pale Blue Dot” (that’s you at right) that the members of a society have been relieved of the strain of producing for themselves by technology that improves efficiency and, more importantly, vastly increases quantity. If I take the comparison to the extreme, the Constellations that represented tools or deities have been replaced in many societies by the gigantic billboards that celebrate the financial well-being of companies continuing their crusade to relieve you of your currency, an economic reality impossible in a society where everyone’s working entirely to maintain a base subsistence level. The world remains in transition towards a time when all are at the same technological level as the First World countries (and it is only a matter of time), meaning something as simple to many of you reading this as an animal-driven plough remains a vital key to survival in other parts of the world.

I vote we re-designate the “Summer Triangle” as the “Summer Plough!”

While it may have been a signal for a Late-Summer party at the very beginning of some harvest, the Babylonians used the presence of their Triangulum to mark the “Way of Enlil,” the apparent path of the Sun after the Summer Solstice. In a society that used the Heavens as their Calendar, this simple Constellation took on a wholly more significant meaning.

Thanks to wikipedia, I know that a more recent attribution (to only the Triangle, not the Plough) of this Constellation is to the goddess Ceres, who successfully convinced the god Jupiter to add the island of Sicily (at left, the football that the boot of Italy appears to be kicking towards the U.S.) to the Night Sky (perhaps a preferred way to leave your mark in history, esp. given the alternative taken by Atlantis).

Sicily, featuring an active Mount Etna (Image by Jacques Descloitres, NASA MODIS Land Rapid Response Team).

Given this most interesting history, is there anything to actually do with a pair of eyes or an eyepiece in this part of the sky? I’m pleased to report that this part of the sky is actually quite busy (the Star Map at this beginning of this article is about as busy as one can get without looking at Sagittarius), with Triangulum serving as a useful anchor for finding a number of objects in our Eastern sky this month.

M33, the Triangulum Galaxy. Photo by Hunter Wilson.

As it happens, one of the precious few naked eye galaxies (provided ideal viewing conditions) in the Northern Sky lies just to the South (to the right as you’re looking at it) of α-Tri. M33 (at right), appropriately named the “Triangulum Galaxy,” is a member of the Local Group of galaxies (the most famous member being our Milky Way, the second most famous being the Andromeda Galaxy) and, at 2.9 million light years away, lies (by some estimates) 700,000 light years farther from us than the Andromeda Galaxy (M31) AND, according to measurements using the Very Long Baseline Array, is moving at 190 km/second relative to us and towards M31 (the demolition derby will not be pleasant for M33, given it contains only 4% of the stars of M31 (how many mopeds are there in a semi-rig?). It is still under debate as to whether or not M33 is a companion galaxy to the more massive M31 (they do share proximity), but it certainly stands on its own as a spectacle in a good telescope on a dark night. This first recorded observation (it all comes down to paper) is attributed to Giovanni Battista Hodierna around 1650 (above at left), the most famous recorded observation (it all comes down to publication) can be given to Charles Messier (above at right) on August 25-26, 1764 (now that’s bookkeeping!).

Giovanni Battista Hodierna (left) and Charles Messier (right).

All of the other objects in the boundaries of Triangulum are dim (10>th order or dimmer), making your time spent with moderate optics in this area short compared to the time you’d likely spend just on M31 alone. As a good practice for the next Messier Marathon, you can use M33 (*1) and M31 (*2) to mark the Southern side of a rectangle composed of M33, M31, M34 (*3) and M76 (*4, these last two are right on the Perseus-Andromeda border). As M33 will give you M32 and M101, that’s a quick-six to check off as you plough your way through the list of 110.

Comet Hartley 2 and NGC 457 (the E.T. Cluster). Photo by SAS member Stu Forster.

AND, as long as were in this neck of the woods (and the tree line in this part of the sky at Darling Hill is now just becoming more bearable to the impatient observer with the falling of leaves), we can use the Babylonian form of Triangulum to quickly point our way to M76, then slowly walk the Telrad to the North (left) until we reach the Southern Double of the famed Double-Double, which then puts into view both members of the Perseus Double-Double Cluster (NGC 884 and NGC 869) and Comet Hartley 2, which is working its way through our neighborhood. Our own Stu Forster managed to capture Hartley (green glow at left) as it passed through the local neighborhood of NGC 457, more commonly known as the Owl or E.T. Cluster (yes. tha E.T., the two bright eyes work for both).

Clear skies, Damian

Some Light Science Reading. The Constellations: Coma Berenices

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

Constellation Map generated with Starry Night Pro 6.

I continue to groom the Eastern sky in this month’s Constellation presentation by spending some time conditioning you to appreciate the subtle shapeliness and glowing highlights just a short clip from last month’s subject, Canes Venatici (I will endeavor to refrain from additional dry hair humor in the rest of the article). Coma Berenices, or “Berenice’s Hair,” is an unusual constellation in many respects. It is one of the few constellations that owes its name (and history) to an actual person, is one of the constellations that was promoted from a lowly asterism, it marks the location of the North Galactic Pole, and, as one of the edge-sharing constellations with Virgo, Coma Berenices contains a plethora of Messier Objects (and is an excellent constellation to have memorized if binocular viewing is in your future and you just don’t wanna wait to find something). As has been a general theme with many of these past articles, even the most simple constellations have weaved into them a wealth of astronomical treasures.

“The lives of the priests were almost cut as short as Queen Berenice’s hair.” I have to assume this line has been told in one form or another over the course of the last few millennia as part of the discussion of this simple right angle. Queen Berenice II was the wife of King Ptolemy III Euergetes of Egypt, perhaps best known as the monarch under whom the great port city of Alexandria, home to such notable Greek mathematicians as Euclid and Pappus (you did know what I meant by a “right angle,” didn’t you?) rose to prominence. As history tells us, Ptolemy rode off to seek revenge for the death of his sister, Berenice promised the goddess Aphrodite her hair upon Ptolemy’s safe return, Aphrodite saw fit to collect on said offering, and Berenice offered her golden locks to Afro, er, pardon, Aphrodite’s temple. As if her bad hair day were not enough, the next morning found her offering gone from the temple. The court astronomer Conon of Samos offered the most logical explanation (much to the relief of the temple priests, who were close to getting a far-too-close shave of their own), one which was so convincing that it remains with us today. Aphrodite, well, washed that hair right away from those men, and sent it on its way… skyward. What we now know as Coma Berenices had, at one time (and likely for some amount of time after), been the furry end of the tail of Leo the Lion, Berenice’s close and equally blonde companion. It is believed that Come Berenices graduated from asterism (simply any collection of stars that are NOT official constellations) to constellation with the help of Tycho Brahe in his 1602 star catalogue (reinforced by Johann Bayer in his 1603 work, Uranometria).

The dwarf planet Makemake.

It is a testament to the changing times that I can mention the presence of a planetary neighbor tangled in Coma Berenices that I would not have known to mention when the new SAS newsletter began its membership cycle only two years ago. The dwarf planet Makemake (shown above from a Hubble image and provided to wikipedia by Mike Brown, its discoverer) is currently veryvery close to the south-most bright star, gamma-Com. While helping to provide a marker for one of the smallest catalogued objects in the Night Sky, Coma Berenices also marks an important location for our most important source of observables in the same Sky. The North Galactic Pole (position shown below), is the point 90 degrees above us with respect to the galactic plane (the discussion of the Galactic Coordinate System is far too, well, large to include here, so I refer you to its wikipedia entry HERE).

The North Galactic Pole

Coma Berenices hosts a single Messier Object that is not a galaxy, although, like hair, detail is based on proximity. M53 is a bino-visible (7.7 magnitude) globular cluster approximately 65,000 light years away. As is often the case, our terran view (especially in CNY) does not do this object the justice provided by our tax dollars in the form of Hubble images (shown below). Looking at the constellation image at the top of this article, you may notice a bit of a knot just to the right of Makemake. As it happens, the density of stars in this region of Coma Berenices is high enough that is does have a designation as the very open cluster Melotte 111 in the less well known “other-M” Melotte catalogue. We are far too close to it for the cluster to appear to us as something like the densely-packed Pleiades, but there may be a close-by planet to the Pleiades saying the same thing about the region around our gamma-Com!

M53

The rest of the Messier Objects in Coma Berenices are galaxies, with all but one of them bright (close-by) members of the Virgo Cluster, the gigantic collection of up-to 2000 galaxies discussed briefly in last month’s newsletter. Coma Berenices and its border with Virgo are regions that all Messier Marathoners cannot wait to have appear prominently in their early-morning March skies, as finding and checking-off these objects in your race-to-the-finish search as fast as two-in-one shampooing. The six Virgo members are (listed top-down) M85, M100, M98, M99, M88, and M91. You will note that M86, M84, M90, M89, M87, M58, M59, and M60 (phew!) are also in very close proximity in Virgo. Your problem is not finding smudge patches in your binoculars. You’re problem is finding out which one you’re looking at!

The lenticular (a morphological hybrid between elliptical and spiral galaxy shapes) galaxy M85 (NGC 4382) marks the northernmost edge of the Virgo cluster. Admittedly, the detail in the Hubble image is a bit lacking (shown below), one of the signs of an old elliptical galaxy where star formation is no longer ongoing in any significant amount). This galaxy lies 60 million light years away and is the 94th MOST distant Messier Object. With M85 centered in your Telrad, you’ll find M100 just at the edge of your outer ring.

M85

M100 (NGC 4321, shown at below-left from ESO) has a shape to it that all likely think of when they picture a galaxy in their mind’s eye. One of the most prominent members of the Virgo cluster, this “grand design spiral” galaxy is 55 million light years away and has been observed intensely enough for us to know that it hosts the satellite galaxy NGC 4323. As galaxies go, M100 is jumpin’ with supernovae, with five catalogued since 1901. Centering your Telrad on M100, M99 approaches your outer ring by about the amount that M98 and M88 sits beyond it.

M100

We see the spiral galaxy M98 (NGC 4192, shown below, from Astrofotografia) almost edge-on, making for a view similar to, but less interesting that, the Andromeda Galaxy (M31). If you’re keeping excellent track of your Doppler shifting, you’ll note that M98 is racing towards us at 125 km/sec which, at 60 million light years away, gives us plenty of time to hit the salon before its arrival.

The image of the pinwheel-looking (a name that already has the galaxy M33 associated with it) M99 (below), was taken by amateur astronomer Hunter Wilson and is currently the choice image at wikipedia for this galaxy (no small feat considering the telescope competition both on the ground AND in orbit). The slight unwinding (well, slight to our eyes, but tens of thousands of light years fit into that gap) of the right-most arm is attributed to VIRGOHI21, a region of hydrogen gas and a massive amount of presumed dark matter.

M99

The spiral galaxy M88 (NGC 4501, shown below and also by Hunter Wilson) is racing towards the center of the Virgo cluster (in the direction of M87). This galaxy is noteworthy for its very tight and very regular spiraling that falls smoothly all the way to the galaxy core, home of a supermassive black hole 80 million times the mass of the Sun.

M88

The last Messier member of the Virgo cluster in Coma Berenices is M91 (NGC 4548, shown below). Messier (in 1781) and Herschel (in 1784) both lay claim to its discovery despite the gap in timing. The linked picture for this image is as noteworthy for the soft blending of nebulosity and starry regions as for the multitude of small galaxies also contained in the field of view. Well worth a look.

M91

Finally, the outlier Messier galaxy in this region is M64 (NGC 4826, shown below), known to amateur astronomers as the Black Eye Galaxy. This view is obvious even in our telescopes! Not only is the galaxy interesting for the dark band pointed towards us, but it has become doubly-interesting recently with the discovery that the black band is spinning in the opposite direction of the rest of the galaxy, with the current hypothesis being that the black band is the remains of a companion galaxy that may have collided with the central galaxy one billion years ago. when you next see it, think of the astronomer Conon and the priests he saved from a similar fate.

M64

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 Bootes‘ 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 Bootes 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 Bootes, 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