Starship Asterisk*

Posted: **Tue May 26, 2009 1:07 pm**

Asterion & Chara (2009 May 26)

http://apod.nasa.gov/apod/ap090526.html
http://antwrp.gsfc.nasa.gov/apod/ap050719.html
http://antwrp.gsfc.nasa.gov/apod/ap021121.html
http://antwrp.gsfc.nasa.gov/apod/ap010613.html
http://antwrp.gsfc.nasa.gov/apod/ap000215.html
http://antwrp.gsfc.nasa.gov/apod/ap070411.html
http://antwrp.gsfc.nasa.gov/apod/ap080417.html
http://antwrp.gsfc.nasa.gov/apod/ap071012.html
http://antwrp.gsfc.nasa.gov/apod/ap000107.html
http://antwrp.gsfc.nasa.gov/apod/ap070609.html
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Canes Venatici (from Wikipedia)

<<Canes Venatici is a small northern constellation that was created by Johannes Hevelius in the 17th century. Its name is Latin for hunting dogs and it represents the mythological dogs Chara and Asterion being held on a leash by Boötes the herdsman, a neighboring constellation.

Canes Venatici depicted in an old star atlas.

Canes Venatici contains some bright stars, but before the seventeenth century it was treated as part of the constellation of Bootes the herdsman. Its identification with Bootes's dogs arose through a mistranslation. Some of its component stars were traditionally described as representing Bootes's cudgel (Greek, Κολλοροβος). When the Greek astronomer Ptolemy's Almagest was translated from Greek to Arabic, the translator did not know the Greek word and rendered it as the nearest-looking Arabic word, and wrote العصى ذات الكلاب in ordinary unvowelled Arabic text "al-`aşā dhāt al-kullāb", which means "the spearshaft having a hook", probably thinking of a shepherd's crook. When the Arabic text was translated into Latin, the translator (probably in Spain) mistook the Arabic word كلاب for kilāb, meaning "dogs", writing hastile habens canes ("spearshaft having dogs").

These spurious dogs floated about the astronomical literature until Hevelius decided to specify their presence in the sky. Hevelius named α CVn Asterion (now known as 'Cor Caroli') and another Chara; these names are Greek for "Little star" and "Bright female one". These were sometimes regarded as an independent constellation or at least an asterism. Canes Venatici is now one of the 88 official modern constellations.

The constellation's brightest star is Cor Caroli (α² CVn), named by Sir Charles Scarborough in memory of King Charles I, the deposed king of Britain. It is of magnitude 2.90.

La Superba (Y CVn) is a semiregular variable star that varies between magnitudes 4.7 and 6.2 over a period of around 158 days. It is a carbon star and is famous for being deep red. AM CVn, a very blue star of magnitude 14, is the prototype of a special class of cataclysmic variable stars, in which the companion star is a white dwarf, rather than a main sequence star. RS CVn is the prototype of a special class of binary stars of chromospherically active and optically variable components.

Canes Venatici contains five Messier objects, including four galaxies. One of the more significant galaxies in Canes Venatici is the Whirlpool Galaxy (M51, NGC 5194) and NGC 5195, a small barred spiral galaxy that is seen face on. This was the first galaxy recognised as having a spiral structure, this structure being first observed by Lord Rosse in 1845.

Other notable spiral galaxies in Canes Venatici are the Sunflower Galaxy (M63, NGC 5055), Messier 94 (NGC 4736), and Messier 106 (NGC 4258).

Messier 3 (NGC 5272) is a globular cluster. It is 18' in diameter, and at magnitude 6.3 is bright enough to be seen with binoculars.>>
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Posted: **Tue May 26, 2009 1:17 pm**

http://apod.nasa.gov/apod/ap090526.html

Kind of looks like the beautiful spiral galaxy is being gradually destroyed by the smaller galaxy. Notice how the star field seems to be dissolving as it enters the smaller entity. Does the bright core of the smaller galaxy suggest a super massive black hole?

Orin

Posted: **Tue May 26, 2009 1:41 pm**

orin stepanek wrote:Kind of looks like the beautiful spiral galaxy is being gradually destroyed by the smaller galaxy. Notice how the star field seems to be dissolving as it enters the smaller entity. Does the bright core of the smaller galaxy suggest a super massive black hole?

M51 almost certainly has a supermassive black hole at its core. But the interacting dwarf galaxy NGC 5195 most likely does not. And while the future result of this interaction is uncertain, it is likely that recent interactions (NGC 5195 has passed through the disc of M51 at least twice in the last few hundred million years) have enhanced the spiral structure of M51, and are also responsible for much of the new star formation that can be seen in that galaxy.

Posted: **Tue May 26, 2009 1:47 pm**

The large galaxy is a truly clear example of how time is created by the enormous energies involved in the whirl of the galaxy. Seen edge-on the galaxy will appear flat, with the central buldge, but face on the centre is clearly far, far ahead in time, the arms trailing progressively further behind as they progress towards their Outer Limits. A beautiful photo besides.

Posted: **Tue May 26, 2009 4:14 pm**

First, I am not an astronomer but just an old guy that has enjoyed this site for as long as it has been posted.

Looking at the site today, both galaxies appear awash in light. Would anyone hazard a guess as to what the sky would look like on a planet in one of the 2 galaxies?
It appears to me that there is so much direct as well as ambient light in the two galaxies that there would be no darkness at all on any planet in either galaxy.

Would anyone agree or disagree?

Thank you,

john chalmers

Posted: **Tue May 26, 2009 4:44 pm**

Our galaxy, the Milky Way, is also "awash in light". I've read here in the APOD fora that our galaxy looks a lot like Andromeda does to us. So why don't we see a wildly different night sky than we do? A lot of the star light is blocked from our view by gas and dust in the Milky Way; a lot more is attenuated by passage through our atmosphere; and a lot of it is just plain too far away and amounts, from our point of view, to nothing more than a tiny speck of light surrounded by vast amounts of more or less empty space. Yes, even within the Milky Way (or M51) space is mostly empty.

Now if our eyes could see more wave lengths of energy, then we might see a more interesting night sky and perhaps even have a fancy day sky to look at too.

Having said all that, the Andromeda galaxy, to take a large local example, is about 2.5 million LY away, so it's a small object in our sky to the naked eye, at least. A star gazer in M51 could well have a much better view of its nearby galactic neighbours, if they had a clear field of view, unblocked by all the possible dust and gas.

There have been many APOD images which prompt me to ask essentially the same question: I wonder what their night sky looks like? I volunteer to go and find out.

Rob (who is also an old non-astronomer)

Posted: **Tue May 26, 2009 5:21 pm**

Rob, Thank you for the explanation. It was presented just right for my understanding. I have occasionally asked a question on the site, and sometimes the "pros" come off with a slight tinge of . . .exasperation in their answer. I appreciate very much your time.

Have a good day!
john

Posted: **Tue May 26, 2009 5:31 pm**

rstevenson wrote:Our galaxy, the Milky Way, is also "awash in light". I've read here in the APOD fora that our galaxy looks a lot like Andromeda does to us.

There's more than one forum here?
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Forum, n.; pl. E. Forums (#), L. Fora (#). [L.; akin to foris, foras, out of doors.]

1. A market place or public place in Rome, where causes were judicially tried, and orations delivered to the people.

2. A tribunal; a court; an assembly empowered to hear and decide causes.
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rstevenson wrote:So why don't we see a wildly different night sky than we do? A lot of the star light is blocked from our view by gas and dust in the Milky Way; a lot more is attenuated by passage through our atmosphere; and a lot of it is just plain too far away and amounts, from our point of view, to nothing more than a tiny speck of light surrounded by vast amounts of more or less empty space. Yes, even within the Milky Way (or M51) space is mostly empty.

M51 has only a fourth the mass of the Milky Way and a lot of that appears to be dust.

http://en.wikipedia.org/wiki/Whirlpool_Galaxy wrote:
With the recent SN 2008cs derived estimate of 23 Mly distance, it can be inferred that M51's bright circular disk has a radius of about ~38,000 light-years. Its mass is estimated to be 160 billion solar masses. The cross within the nucleus of M51 indicating two dust rings around the black hole at the center of the nebula. A black hole, surrounded by a ring of dust, is thought to exist at the heart of the spiral. The dust ring stands almost perpendicular to the relatively flat spiral nebula. A secondary ring crosses the primary ring on a different axis, a phenomenon that is contrary to expectations.

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rstevenson wrote:Now if our eyes could see more wave lengths of energy, then we might see a more interesting night sky and perhaps even have a fancy day sky to look at too.

Many of those wave lengths are so absorbing (or highly scattered) in our atmosphere that we would have trouble driving our cars.

rstevenson wrote:Having said all that, the Andromeda galaxy, to take a large local example, is about 2.5 million LY away, so it's a small object in our sky to the naked eye, at least. A star gazer in M51 could well have a much better view of its nearby galactic neighbours, if they had a clear field of view, unblocked by all the possible dust and gas. There have been many APOD images which prompt me to ask essentially the same question: I wonder what their night sky looks like? I volunteer to go and find out.

Would you be willing to fly coach?

Art Neuendorffer (I am not an astronomer but I play one on various fora)

Posted: **Tue May 26, 2009 5:55 pm**

john chalmers wrote:Looking at the site today, both galaxies appear awash in light. Would anyone hazard a guess as to what the sky would look like on a planet in one of the 2 galaxies?
It appears to me that there is so much direct as well as ambient light in the two galaxies that there would be no darkness at all on any planet in either galaxy.

It's worth keeping in mind that this is an image that was made by collecting light for hours. You can see M51 with binoculars, and to the eye it appears as a fuzzy gray spot. The thing about extended sources (like galaxies and nebulas) is that they don't get any brighter as you get closer. If you cut the distance in half, the total intensity is four times brighter (because of 1/r^2), but the object covers four times the area. So the surface brightness is the same. If you were very close to M51, what looks like a small, fuzzy gray spot from here would look like a big fuzzy gray spot. In fact, we see exactly the same thing when we view our own galaxy: the river of faint light running across the sky that we call the Milky Way.

If you've been following APOD for a while, you've probably seen some long exposure photos of the Milky Way. They typically show a sky "awash in light", with lots of color and structure. The overall appearance, in fact, is quite similar to what long exposure images of other galaxies show. Yet our eyes see no more than a faint band of gray light.

Posted: **Tue May 26, 2009 7:18 pm**

neufer wrote:
rstevenson wrote:Our galaxy, the Milky Way, is also "awash in light". I've read here in the APOD fora that our galaxy looks a lot like Andromeda does to us.
There's more than one forum here?

In the eye of the beholder, yes. Here on The Asterisk*, the "board index" lists three "discussions". I think of each discussion area as a forum in which more or less on topic discussions can take place. Hence each topic area becomes, in my perhaps overly categorized mind, a separate forum. YMMV.

Rob

Posted: **Tue May 26, 2009 7:21 pm**

Chris Peterson wrote: "...Yet our eyes see no more than a faint band of gray light.

I've never looked through a telescope but I've seen the Milky Way looking a LOT brighter than a faint band of gray light.

Posted: **Tue May 26, 2009 7:34 pm**

aristarchusinexile wrote:I've never looked through a telescope but I've seen the Milky Way looking a LOT brighter than a faint band of gray light.

Obviously, this is subjective. My point was that it looks nothing like what a photograph shows, and nothing like images of other galaxies. It doesn't show color, the visible structure is limited, it doesn't cast a shadow (reports of such are anecdotal and probably false).

Posted: **Wed May 27, 2009 1:36 am**

Chris Peterson wrote:M51 almost certainly has a supermassive black hole at its core. But the interacting dwarf galaxy NGC 5195 most likely does not. And while the future result of this interaction is uncertain, it is likely that recent interactions (NGC 5195 has passed through the disc of M51 at least twice in the last few hundred million years) have enhanced the spiral structure of M51, and are also responsible for much of the new star formation that can be seen in that galaxy.

For something without a super massive black hole NGC 5195 sure puts out a lot of x-rays:

http://antwrp.gsfc.nasa.gov/apod/ap020711.html wrote:
Explanation: The number of luminous x-ray sources, likely neutron star and black hole binary systems within the confines of M51, is unusually high for normal spiral or elliptical galaxies and suggests this cosmic whirlpool has experienced intense bursts of massive star formation. The bright cores of both galaxies, NGC 5194 and NGC 5195 (right and left respectively), also exhibit high-energy activity in this false-color x-ray picture showing a diffuse glow from multi-million degree gas.

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Is NGC 5195 some kind of yoke or something?

http://en.wikipedia.org/wiki/NGC_5195 wrote:
<<NGC 5195 (also known as Messier 51b or M51b) is a dwarf galaxy that is interacting with the Whirlpool Galaxy (also known as M51a or NGC 5194). Both galaxies are located approximately 25 million light-years away in the constellation Canes Venatici. The two galaxies are connected by a dust-rich tidal bridge, and the dust in this tidal bridge can be seen silhouetted against the center of NGC 5195. This demonstrates that NGC 5195 appears to lie behind the Whirlpool Galaxy. As a consequence of the gravitational interaction with the Whirlpool Galaxy, NGC 5195 is highly distorted. Classification of its morphology is difficult, as it is sometimes identified as a lenticular galaxy or as amorphous (i.e. irregular). It has been described as falling outside the standard morphological classification system.

Supernova 1945A is the only supernova that has been detected within NGC 5195. The supernova was found 10″ northwest of the nucleus on April 6, 1945 by Milton L. Humason using the 100-inch (2.5 m) telescope at Mount Wilson Observatory. The supernova, classified as a Type I supernova, reached a peak apparent magnitude of 14.0.>>

Posted: **Wed May 27, 2009 2:06 am**

neufer wrote:Is NGC 5195 some kind of yoke or something?

Is that some kind of yolk yoke?

Posted: **Wed May 27, 2009 10:19 am**

apodman wrote:
neufer wrote:Is NGC 5195 some kind of yoke or something?
Is that some kind of yolk yoke?

-----------------------------------
Yolk, n. [OE. yolke, AS. geoloca, geoleca, fr. geolu yellow. See Yellow.]

1. The yellow part of an egg; the vitellus.
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Yoke, n. [OE. yok, oc, AS. geoc; akin to D. juk, OHG. joh, G. joch, Icel. & Sw. ok, Dan. aag, Goth. juk, Lith. jungas, Russ. igo, L. jugum, Gr. , Skr. yuga, and to L. jungere to join. Cf. Join, Joust, Jugular, Syzygy]

1. A bar or frame of wood by which two oxen are joined at the heads or necks for working together.

2. That which connects or binds; a chain; a link; a bond connection.
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Syzygy, n. [Gr. to join.] The conjunction or opposition of a planet with the sun, or of any two of the heavenly bodies.
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Joke, n. [L. jocus. Cf Jeopardy, Jocular, Juggler.]

1. Something said for the sake of exciting a laugh; something witty or sportive (commonly indicating more of hilarity or humor than jest); a jest; a witticism.

2. Something not said seriously, or not actually meant; something done in sport.
-----------------------------------

Art Neuendorffer
(it's NOT ok to contact this poster with services or other commercial interests)

Posted: **Wed May 27, 2009 1:09 pm**

neufer wrote: (it's NOT ok to contact this poster with services or other commercial interests)

Dear Friend of Apod,

The Rooster Roster Hen Happiness Service would like to offer you a discounted trial offer which we guarantee you will increase the happiness of your hens and increase they laying output.

This is no yoke.

Sincerely,

Cocky Dewdle Dew,

Senior Morningstar Gazer

Posted: **Wed May 27, 2009 1:33 pm**

aristarchusinexile wrote:
neufer wrote: (it's NOT ok to contact this poster with services or other commercial interests)
Dear Friend of Apod, The Rooster Roster Hen Happiness Service...

---------------------------------------------------------
"aristarchusinexile" : Let me understand, you got the hen, the chicken and the rooster.
The rooster goes with the chicken. So, who's having sex with the hen?

GEORGE COSTANZA: Why don't we talk about it another time.

"aristarchusinexile" : But you see my point here?
You only hear of a hen, a rooster and a chicken. Something's missing!

MRS. ROSS: Something's missing all right.
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Posted: **Wed May 27, 2009 2:12 pm**

neufer wrote: "aristarchusinexile" : Let me understand, you got the hen, the chicken and the rooster.
The rooster goes with the chicken. So, who's having sex with the hen?

GEORGE COSTANZA: Why don't we talk about it another time.

"aristarchusinexile" : But you see my point here?
You only hear of a hen, a rooster and a chicken. Something's missing!

MRS. ROSS: Something's missing all right.
---------------------------------------------------------[/list]

Well done, Neuf, my only response can be:

http://www.buildingachickencoop.com/?hop=disciples

Disclaimer: This is not a religious reference unless you worship Henhouses/Chicken Coops/Ammonia

Posted: **Wed May 27, 2009 2:31 pm**

aristarchusinexile wrote:
neufer wrote: "aristarchusinexile" : Let me understand, you got the hen, the chicken and the rooster.
The rooster goes with the chicken. So, who's having sex with the hen?

GEORGE COSTANZA: Why don't we talk about it another time.

"aristarchusinexile" : But you see my point here?
You only hear of a hen, a rooster and a chicken. Something's missing!

MRS. ROSS: Something's missing all right.
Well done, Neuf, my only response can be:
http://www.buildingachickencoop.com/?hop=disciples

"As far as I can tell, aristarchusinexile, your entire enterprise is more than
a solitary man with a messy apartment which may or may not contain a chicken."

Posted: **Wed May 27, 2009 3:23 pm**

neufer wrote: "As far as I can tell, aristarchusinexile, your entire enterprise is more than
a solitary man with a messy apartment which may or may not contain a chicken."

The chicken was supposed to clean up the mess, but she flew the coop even before arriving. Some birds are smarter than others, those others having stuck around a while, intoxicated by the scent of ammonia. I need to get into that canoe.

"Hen (変?) is a seinen manga which was the first work created by manga artist Hiroya Oku, who is best known for Gantz. There are two separate series of Hen, but they share the same setting, and characters from the first series appear in the second." From Wiki.

Starship Asterisk*

APOD: Whirlpool Galaxy Deep Field (2009 May 26)

APOD: Whirlpool Galaxy Deep Field (2009 May 26)

Whirlpool Galaxy Deep Field (2009 May 26)

Re: Whirlpool Galaxy Deep Field (2009 May 26)

Re: Whirlpool Galaxy Deep Field (2009 May 26)

Re: TOday's picture of colliding galaixies.

Re: TOday's picture of colliding galaixies.

Re: Whirlpool Galaxy Deep Field (2009 May 26)

Re: TOday's picture of colliding galaixies.

Re: TOday's picture of colliding galaixies.

Re: TOday's picture of colliding galaixies.

Re: TOday's picture of colliding galaixies.

Re: TOday's picture of colliding galaixies.

Re: Whirlpool Galaxy Deep Field (2009 May 26)

Re: Whirlpool Galaxy Deep Field (2009 May 26)

Re: Whirlpool Galaxy Deep Field (2009 May 26)

Re: Whirlpool Galaxy Deep Field (2009 May 26)

Re: Whirlpool Galaxy Deep Field (2009 May 26)

Re: Whirlpool Galaxy Deep Field (2009 May 26)

Re: Whirlpool Galaxy Deep Field (2009 May 26)

Re: Whirlpool Galaxy Deep Field (2009 May 26)