David_leeD.061001
Member
Joined: 02 Oct 2006
Posts: 1907
Location: At Astronomy.fm
|
 Posted: 23 Oct 06 07:27 Post subject: Attention: Artist at Work!! |
 |
|
Last week we followed the flight of the Phoenix...learning about it's 500 year life-span...from tiny worm, to majestic bird, then finally to it's fate of giving his life in order that a younger fire-bird may follow it's path of destiny. This week, we are continuing to chart the waters of the "Autumn Ocean". This barren swath of sky, at least as far as bright stars are concerned, rightly contains many of the aquatic themed constellations. These include the celestial river of Eridanus, a couple of fish, Pisces & Pisces Austrinus, the sea-monster of Cetus, and several birds amongst others.
It's not a HUGE stretch of imagination to be able to picture the birds as swooping down & grabbing a bite to eat off of the surface of the water, but stuck right there between the river, fish, sea-monster, & birds is an out-of-place constellation called Sculptor, or occasionally El Escultor, which is the Spanish version. Sculptor was first introduced in 1756 by Nicolas Louis de Lacaille, as "L'Atelier du Sculpteur"---the Sculptor's Studio. Thankfully, shortly before his death, he changed the name to a more appealing "Apparatus Sculptoris"---the Latinized & simplified version.
It is not entirely known if Lacaille had any SPECIFIC studio in mind for his original name to represent, or if he was just trying to fill in a vacant area of the sky with some object. Many suspect the former, since Lacaille also performed an ego-trip by inventing a constellation to represent his own observatory---Mensa, the Table Mountain---named after the plateau in South Africa where he performed many of his observations. But the man was not an artist, although an excellent astronomer, so it almost surely wasn't named after something of HIS...perhaps an artistic friend. But this was all made moot by the renaming, which changed it's meaning to "the Sculptor's Apparatus", roughly Latin for "tool".
The original drawing in Lacaille's 1756 planisphere showed a carved head on a tripod table, with the artist’s mallet and two chisels on a block of marble next to it. When the name was changed, his next planisphere pictured the constellation without the block of marble and moved the sculptor’s tools to the top of the table along with the carved bust.
Apparatus Sculptoris went main-stream when Johann Bode published it in his Uranographia of 1801. (Not Uranometria by Johann Bayer. This chart also popularized several new constellations, but 200 years earlier.) Oddly, all new constellations in Bode's publication were later removed or replaced, with the sole exception of Apparatus Sculptoris, while ALL of Bayer's additions remain in use up till today. (Mensa had already been accepted, thus, wasn't a "new" one.) The only other hint at Bode's contributions is the Quadrantid meteor shower, which peak on January 3rd, in our constellation of Bootes. Bode named this area "Quadrans Muralis"---the Mural Quadrant. With names such as "Officina Typographica", "Apparatus Chemica", "Globus Aerostaticus", "Honores Frederici", "Felis", & "Custos Messium", its a wonder that ANY of them survived. Although "Felis" would have been neat. The sky needs a cat in it to chase away the lizards & give the dogs something to play with. 
It is unknown when the name was officially changed to the modern day "Sculptor", but it was probaly in the 19th century. The constellation is commonly referred to as "the Sculptor", but this is somewaht inaccurate. It more correctly represents "the Sculptor's Tool". Remember, even through the renamings, it has never represented a person, which is a sculptor, but one of the instruments he uses to do his job.
As is typical with almost all of these obscure Fall constellations, Sculptor can not claim a large amount of interesting objects like most of it's brighter counterparts can. But there are a few points of interest within that deserve investigation. There are a handful of mostly dim galaxies here, many belonging to the same group as the ones in Phoenix. A couple of these are rather good also. There's one lonely globular cluster, plus a few interesting binaries. There is also one other very interesting, although "unseeable" location within Sculptor.
NGC55 is a fine example of an edge-on galaxy. It is also one of the closest outside our Local Group, although astronomers have had trouble exacting it's distance. A value of 7-10 million light years is the most common estimate, which would give it a diameter of about 70,000 light years, which sounds reasonable. One odd thing about this galaxy is the lack of a noticeable core. It greatly resembles M82, but does not hint at the turmoil that gave the latter galaxy it's odd shape.
NGC 253 is most likely the finest galaxy in the sky, with the exception of the Andromeda. However, due to it's southern location, it wasn't as well known until telescopes started migrating south around 25 years ago. It's distance is comparable to NGC55, but this one has a more classic spiral structure. Although it lies at about the same angle as the Andromeda, it's structure is not quite as apparent owing to the vast amount of scattered dust clouds, but this only enhances the galaxy's photogenics.
The last galaxy that we are going to study is one that we MIGHT see, but probaly won't RECOGNIZE. The Sculptor System, or Sculptor Dwarf Galaxy, was found by Harvard Observatory in 1938, along with a similar one called the Fornax System. The dwarf is a member of the Local Group, & possibly a satellite of our own galaxy. It is about 35% more distant than the Magellanic Clouds, but only 1/10th the size. This fact, added to the facts that it is extremely low density & it's brightest stars are only slightly above the 18th magnitude, make it an extremely difficult object to see...or even to photograph.
Another oddity within Sculptor is the open cluster, Blanco 1...occasionally known as the Zeta Sculptoris Cluster. This a target for low-powered observation & includes about a dozen stars scattered in a loose "V" around Zeta. Blanco is one of the few open clusters situated far from the Galactic Plane, thus, the exact nature of it's developement is a mystery. However it formed, it is known to be a relatively young cluster.
There are a couple of variables in Sculptor worth keeping track of, most notably S & RT, and the best multiple systems are probaly Kappa-1, Tau, & H1991. There are no stars in the constellation that have any names in current useage.
Finally, we can see one lone globular within Sculptor, which is NGC288. It is somewhat loose & unorganized, but just SW of it is a much more interesting locale...although you just have to pretend that you are actually seeing it. It's the South Galactic Pole. The North Galactic Pole is on the other side of the sky, in Coma Berenices. When you have your scope pointed to either of these locations, you are looking outwards at a 90 degree angle, from the core of our own galaxy...deep into the reaches of space, unpopulated by anything within our spiral-armed home.
Now you know why this region of the "Autumn Ocean" is so much more sparse than other areas of the sky.
Next week, we will continue our great voyage north into the very heart of our deep celestial sea, where we will come face-to-face with a great monster, which almost spelled doom for the chained maiden thousands of years ago...& investigate this monsters "heart"...a star called, "The Wonderful". (Is it just me, or does "monster" & "wonderful" just not work well together??)
Sculptor--Scl--Sculptoris--The Sculptor's Tool
475 Square Degrees--Rank 36th in area
Number of stars above Mag.3--None
Best visible between latitudes +50/-90.
Brightest Stars:
-Alpha-----------4.3---005836/-292127
-Beta------------4.4---233258/-374906
-Gamma--------4.4---231849/-323155
-Delta-----------4.6---234856/-280748
-Eta-------------4.9---002756/-330026
Multiple Stars:
-Kappa-1-------6.1/6.2/1.4"----000921/-275916
-Tau-------------6.0/7.4/0.8"----013608/-295426
-Lambda-1-----6.6/7.0/0.7"----004243/-382748
-H1991---------6.6/9.7/47.1"---003849/-250628
-LAL192--------6.8/7.4/6.4"----235421/-270234
Variable Stars:
-S----------------001522/-320243
-RT---------------003628/-254025
Deep Sky:
-NGC288--------005248/-263500---(Globular)
-NGC55---------001454/-391100---(Galaxy)
-NGC253--------004736/-251800---(Galaxy)
-Scl Dwarf------005954/-334200---(Sculptor System Dwarf Galaxy)
-Blanco1--------000418/-295600---(Open Cluster)
-S.G.P.----------005124/-270700---(South Galactic Pole)
-IC5332--------233430/-360559---(Galaxy)
-NGC134--------003024/-331500---(Galaxy)
-NGC300--------005454/-374100---(Galaxy)
-NGC7793-------235748/-323550---(Galaxy)
Auxilio ab alto, Prorsum ad astra---By help from on high, onward to the stars!!
_________________
Last edited by David_leeD.061001 on 25 Oct 06 02:17; edited 2 times in total |
|
FAQ 
Search 
Memberlist 
Usergroups
Register
Profile 
Log in to check your private messages 
Log in 
