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APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Fri Sep 10, 2010 4:01 am
by APOD Robot
Vela Supernova Remnant
Explanation: The plane of our Milky Way Galaxy runs through this
complex and beautiful skyscape. At the northwestern edge of the constellation
Vela (the Sails) the four frame mosaic is over 10 degrees wide, centered on the glowing filaments of the
Vela Supernova Remnant, the expanding debris cloud from the death explosion of a massive star. Light from the supernova explosion
that created the Vela remnant reached Earth about 11,000 years ago. In addition to the shocked filaments of glowing gas, the cosmic catastrophe also left behind an incredibly dense, rotating stellar core, the
Vela Pulsar. Some 800 light-years distant, the Vela remnant is likely
embedded in a larger and older supernova remnant, the
Gum Nebula.
[/b]
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Fri Sep 10, 2010 4:25 am
by neufer
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Fri Sep 10, 2010 1:07 pm
by owlice
This image appeared in August on the Observation Deck
here.
Congratulations to Marco Lorenzi on his image's selection as today's APOD!
NOVELA
Posted: Fri Sep 10, 2010 1:10 pm
by neufer
http://en.wikipedia.org/wiki/Novella wrote:
<<A novella is a written, fictional, prose narrative longer than a novelette but shorter than a novel. The Science Fiction and Fantasy Writers of America Nebula Awards for science fiction define the novella as having a word count between 17,500 and 40,000.
The novella is a common literary genre in several European languages. English language novellas include Anthony Burgess's A Clockwork Orange, John Steinbeck's Of Mice and Men, Herman Melville's Billy Budd, George Orwell's Animal Farm, Truman Capote's Breakfast at Tiffany's, Ernest Hemingway's The Old Man and the Sea, Robert Louis Stevenson's Dr Jekyll and Mr Hyde, Charles Dickens' A Christmas Carol, Philip Roth's Goodbye, Columbus, Joseph Conrad's Heart of Darkness, and Jack Kerouac's The Subterraneans.
The English word "novella" is derived from the Italian word "novella", feminine of "novello" which means new.
A novella has generally fewer conflicts than novels, yet more complicated ones than short stories. The conflicts also have more time to develop than in short stories. They have endings that are located at the brink of change. Unlike novels, they are not divided into chapters, and are often intended to be read at a single sitting, as the short story, although white space is often used to divide the sections. They maintain, therefore, a single effect. Warren Cariou wrote:
The novella is generally not as formally experimental as the long story and the novel can be, and it usually lacks the subplots, the multiple points of view, and the generic adaptability that are common in the novel. It is most often concerned with personal and emotional development rather than with the larger social sphere. The novella generally retains something of the unity of impression that is a hallmark of the short story, but it also contains more highly developed characterization and more luxuriant description.
The idea of serialized novellas dates back to the One Thousand and One Nights, also known as the Arabian Nights, from around the 10th century. The novella as a literary genre later began developing in the early Renaissance literary work of the Italians and the French. Principally, by Giovanni Boccaccio (1313–1375), author of The Decameron (1353)—one hundred novelle told by ten people, seven women and three men, fleeing the Black Death by escaping from Florence to the Fiesole hills, in 1348; and by the French Queen, Marguerite de Navarre (1492–1549) author of Heptaméron (1559)—seventy-two original French tales (structured like The Decameron).
Not until the late eighteenth- and early nineteenth centuries did writers fashion the novella into a literary genre structured by precepts and rules. Contemporaneously, the Germans were the most active writers of the "Novelle." For the German writer, a novella is a fictional narrative of indeterminate length—a few pages to hundreds—restricted to a single, suspenseful event, situation, or conflict leading to an unexpected turning point (Wendepunkt), provoking a logical, but surprising end; "Novellen" tend to contain a concrete symbol, which is the narration's steady point.>>
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Fri Sep 10, 2010 1:15 pm
by emc
“Everything about him was old except his eyes and they were the same color as the sea and were cheerful and undefeated.”
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Fri Sep 10, 2010 1:18 pm
by León
The star that gave rise to the nebula is now the Vela Pulsar
![Image](http://1.bp.blogspot.com/_IFLtLt_K5Ds/TIokoelDmeI/AAAAAAAADp0/EeyhRxD0zvk/s400/velapulsar_cxo.jpg)
The name corresponds to the ship of the Argonauts
![Image](http://4.bp.blogspot.com/_IFLtLt_K5Ds/TIooCCPDx_I/AAAAAAAADqM/OAemu_0yR6A/s400/argonautas.jpg)
So what I have to know the gases are H-alpha, Oxygen and Nitrogen III, I would like to know the existence of other elements.
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Fri Sep 10, 2010 2:53 pm
by orin stepanek
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Fri Sep 10, 2010 3:32 pm
by Ann
This is a very interesting picture, strongly red and blue-green in color balance. I guess that filters aimed at bringing out H-alpha and OIII emission have been used.
The picture really succeeds in bringing out exquisite detail in the supernova remnant. I can't remember that I have ever seen an image of this object that so clearly brings out the circular shell at the center of the nebula.
It would have been fun if there had been an arrow pointing out the general location of the Vela pulsar.
Please note the bright blue star on the lower right, the remarkable binary star Gamma Velorum. One component of this star is an O-type supergiant and the other is a Wolf-Rayet star, a blue supergiant star which has become unstable so that it sheds much of its atmosphere in an incredibly fierce stellar wind. Gamma Velorum is the closest of all Wolf-Rayet stars.
Ann
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Fri Sep 10, 2010 3:47 pm
by Chris Peterson
Ann wrote:This is a very interesting picture, strongly red and blue-green in color balance. I guess that filters aimed at bringing out H-alpha and OIII emission have been used.
Yes, I'd define this as a fairly conventional RGB image, mainly to yield accurate star colors, with an overlay of monochromatic Ha and OIII layers. The image is clearly designed to emphasize structure in the region, and not the actual colors of the nebular areas.
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Fri Sep 10, 2010 5:21 pm
by Boomer12k
Looks like a large balloon kitty!
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Fri Sep 10, 2010 5:52 pm
by biddie67
The APOD paragraph mentions that the Vela Supernova remnant is approximently 800 LY away and that the light from the original supernova explosion reached Earth 11,000 years ago. I'm trying to get my head around something here.
The supernova actually occured around 11,800 years ago and the current blue light in the photograph has arrived here already being 800 Years old. What I find interesting is that the charge to the shocked filaments of glowing gas was so intense that it is still visible after 11,000 years.
Hey, little Vela!
Posted: Fri Sep 10, 2010 6:32 pm
by neufer
http://en.wikipedia.org/wiki/RX_J0852.0-4622 wrote:
<<RX J0852.0-4622 (also known as G266.2−1.2) is a recently discovered supernova remnant. The distance to this object is controversial, but some scientists argue that the supernova remnant is only 650-700 light years away, and
exploded comparatively recently, perhaps within the last 800 years. The remnant is located in the southern sky in the constellation Vela ("sail"), and sits (in projection) inside the much larger and older Vela Supernova Remnant. For this reason, RX J0852.0-4622 is often referred to as Vela Junior. It was found in 1998 when gamma ray emissions from the decay of 44Ti nuclei were discovered using The Imaging Compton Telescope, (COMPTEL).
If the remnant is indeed young and nearby, its corresponding supernova should have been visible from the Earth in about the year 1250. One difficulty with this interpretation is that there are no contemporary written reports of any supernova at that time or in that part of the sky.>>
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Fri Sep 10, 2010 6:44 pm
by mexhunter
Ann wrote:This is a very interesting picture, strongly red and blue-green in color balance. I guess that filters aimed at bringing out H-alpha and OIII emission have been used.
According to the author's own filters and time involved are:
Ha (920m) OIII (890) R (160m) G (160m) B (160m)
Regards
César
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Fri Sep 10, 2010 6:48 pm
by Beyond
ann wrote: I guess that filters bringing out H-Alpa and OIII emission have been used
Ann, i take it that the OIII is not the same OIII we have on earth after a thunder shower?? If it was, i should think that space would smell really good, almost Heavenly
![Exclamation :!:](./images/smilies/icon_exclaim.gif)
With all the dust in space and the explosions and things that go on out there, i should think it would smell more like the inside of a vacuum claener
![Exclamation :!:](./images/smilies/icon_exclaim.gif)
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Fri Sep 10, 2010 7:04 pm
by bystander
OIII narrow bandwidth filters are used to capture light emission from triply ionized oxygen, O
-3.
The O
3, ozone, after a thunder storm is not the same thing.
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Fri Sep 10, 2010 7:17 pm
by Chris Peterson
mexhunter wrote:According to the author's own filters and time involved are:
Ha (920m) OIII (890) R (160m) G (160m) B (160m)
To be clear, those are the exposure times in minutes through each filter. Ha is 656.3nm, OIII is a doublet at 496/501nm. Both filters will be narrow, on the order of 5-10nm pass band. The R, G, and B filters are broad, with overlap between each.
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Fri Sep 10, 2010 8:40 pm
by neufer
emc wrote:
- “Everything about him was old except his eyes and they were
the same color as the sea and were cheerful and undefeated.”
"No good book has ever been written that has in it symbols arrived at beforehand and stuck in.
...I tried to make a real old man, a real boy, a real sea and a real fish and real sharks.
But if I made them good and true enough they would mean many things". - Earnest Hemingway
Villanova motto:
Veritas, Unitas, Caritas (Truth, Unity, Love)
http://en.wikipedia.org/wiki/The_Old_Man_and_the_Sea wrote:
<<The Old Man and the Sea recounts an epic battle of wills between an old, experienced fisherman and a giant marlin said to be the largest catch of his life. It opens by explaining that the fisherman, who is named Santiago, has gone 84 days without catching any fish at all. He is apparently so unlucky that his young apprentice, Manolin, has been forbidden by his parents to sail with the old man and been ordered to fish with more successful fishermen. Still dedicated to the old man, however, the boy visits Santiago's shack each night, hauling back his fishing gear, feeding him and discussing American baseball—most notably Santiago's idol,
Joe DiMaggio....
A group of fishermen gather the next day around the boat where the fish's skeleton is still attached.
One of the fishermen measures it to be
18 feet from nose to tail. Tourists at the nearby café mistakenly take it for a shark.
-----------------------------------------------------------------
The Note: Episode no.
18
Broadcast date: September
18, 1991
Kramer: I just saw
Joe DiMaggio in Dinky Donuts.
You know, I looked in there and there he was having coffee and a donut.
Jerry:
Joe DiMaggio? In Dinky Donuts?
Kramer: Yeah.
Joe DiMaggio.
Jerry: I'm sorry, if
Joe DiMaggio wants a donut he goes to
a fancy restaurant or a hotel. He's not sitting in Dinky Donuts.
Kramer: Well maybe he likes Dinky Donuts.
George: I don't even like to sit next to a man on an airplane 'cause our knees might touch.
Jerry: I can't see
Joe DiMaggio sitting at the counter
in little tiny filthy smelly Dinky Donuts.
Kramer: Why can't
Joe DiMaggio have a donut like everyone else?
Jerry: He can have a donut, but not at Dinky.
George: I don't even like to use urinals, I've always been a stall man.
Kramer: Look I'm telling-- (he does a double take and looks at George)
I'm telling you, that was
Joe DiMaggio.
George: The guy slept with Marilyn Monroe, he's in Dinky Donuts.
......................................................
Kramer: Hey, I saw DiMaggio in the donut shop again.
Jerry: Uh huh.
Elaine:
Joe DiMaggio?
Kramer:
Joe DiMaggio, you know this time I went in and sat down
across from him and I really watched him. I studied his every move. For example, he dunks.
Elaine:
Joe DiMaggio dunks his donut?
Kramer: That's right.
Jerry: See, now I know it's not him.
Joe DiMaggio could not be a dunker.
Kramer: Oh, he's a dunker.
Elaine: Why couldn't he be a dunker?
---------------------------------------
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Fri Sep 10, 2010 9:31 pm
by Case
Ann wrote:It would have been fun if there had been an arrow pointing out the general location of the Vela pulsar.
No obvious visual counterpart in the image, but the pulsar's coordinates say it should be at the crosshairs.
"This all-sky view from GLAST reveals bright
gamma-ray emission in the plane of the Milky Way (center), bright pulsars and super-massive black holes." The Vela pulsar seems VERY bright in gamma-ray.
![Image](http://img839.imageshack.us/img839/1812/gammarayvelapulsar.png)
Gumbo's magic feather
Posted: Fri Sep 10, 2010 9:54 pm
by neufer
Case wrote:Ann wrote:It would have been fun if there had been an arrow pointing out the general location of the Vela pulsar.
No obvious visual counterpart in the image, but the pulsar's coordinates say it should be at the crosshairs:
![Image](http://www.cel-ebration.com/WDCC_DUMBO_+_TIMOTHY_I.jpg)
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Fri Sep 10, 2010 10:12 pm
by emc
Today’s APOD reminded me of an old man looking out to sea… perhaps a likeness of an upside down Abraham Simpson… what’s in a name though. You know, life is in the details… details make it interesting and challenging and… fun! And life’s rewards are best served by the rich… rich in heart, rich in spirit. Neufer, you are both.
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Fri Sep 10, 2010 10:31 pm
by neufer
emc wrote:Today’s APOD reminded me of an old man looking out to sea… perhaps a likeness of an upside down Abraham Simpson… what’s in a name though. You know, life is in the details… details make it interesting and challenging and… fun! And life’s rewards are best served by the rich… rich in heart, rich in spirit. Neufer, you are both.
Dope Art that makes you feel good?
Thanks, Ed.
![Wink :wink:](./images/smilies/icon_wink.gif)
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Sat Sep 11, 2010 3:44 am
by rita cummins
I use APOD as my desktop and this photo is somewhat stretched out on it. when I saw that face looking out at me I thought it was someone's Halloween joke.
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Sat Sep 11, 2010 5:22 am
by Ann
Thank you, Case, for pointing out the Vela pulsar in the image. And you are so right, this pulsar is really extraordinarily bright in gamma rays.
Thank you, too, neufer, for posting Robert Gendler's beautiful true-color but enhanced-color annotated image of the Vela supernova remnant for comparison. And your "The Old Man and the Sea" comment was a whimsically fun and enjoyable diversion here.
Ann
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Sat Sep 11, 2010 5:44 am
by Ann
biddie67 wrote:The APOD paragraph mentions that the Vela Supernova remnant is approximently 800 LY away and that the light from the original supernova explosion reached Earth 11,000 years ago. I'm trying to get my head around something here.
The supernova actually occured around 11,800 years ago and the current blue light in the photograph has arrived here already being 800 Years old. What I find interesting is that the charge to the shocked filaments of glowing gas was so intense that it is still visible after 11,000 years.
Biddie, I'm not too sure that I understand these things too well myself. But think of it like this. The supernova explosion happened 11,000 years ago, and if the star that exploded was 800 light-years away from us 11,000 years ago, which isn't certain since that star has a proper motion in space which is not the same as the Sun's, then the light from that supernova would have reached us about 10,200 years ago.
The supernova would have faded within a year or so. So the supernova which must have lit up the night skies of the Earth about 10,200 years ago can only have been visible for about a year or so.
But the explosion made huge amounts of gas shoot out from the dying star and collide with the "surrounding medium", the gas clouds that were already present in the vicinity of the exploding star. While the light of the actual supernova faded, the collision between the gas blobs flung out by the supernova and the gaseous medium in the vicinity has been going on ever since the supernova explosion occurred. What has happened is that the gas that was flung outwards 11,000 years ago keeps moving outwards at a high speed (but nowhere near the speed of light) and it keeps colliding with gas surrounding it, and the ongoing collision keeps generating nebular glow. That is, the hydrogen in the gas that was flung out and in the gas surrounding the supernova keeps getting ionized by the force of the ongoing collision and keeps glowing red. Photographing this area with a filter sensitive to red H-alpha light will bring out this red glow. But at the very shock front, where the collision is most violent, oxygen atoms will be ionized and glow blue-green, and this light can be detected if you photograph the area with a filter sensitive to blue-green OIII light.
But if you were to look at this area with the naked eye, there is no way you could see either red or blue-green light here, because this light is too faint for our eyes.
Ann
Re: APOD: Vela Supernova Remnant (2010 Sep 10)
Posted: Sat Sep 11, 2010 11:24 am
by neufer
Ann wrote:biddie67 wrote:
The APOD paragraph mentions that the Vela Supernova remnant is approximately 800 LY away and that the light from the original supernova explosion reached Earth 11,000 years ago. I'm trying to get my head around something here. The supernova actually occured around 11,800 years ago and the current blue light in the photograph has arrived here already being 800 Years old.
Biddie, I'm not too sure that I understand these things too well myself. But think of it like this. The supernova explosion happened 11,000 years ago, and if the star that exploded was 800 light-years away from us 11,000 years ago, which isn't certain since that star has a proper motion in space which is not the same as the Sun's, then the light from that supernova would have reached us about 10,200 years ago.
![Image](http://upload.wikimedia.org/wikipedia/commons/7/73/Cycle_of_pulsed_gamma_rays_from_the_Vela_pulsar.gif)
Vela pulsar 89 ms cycle of gamma rays
biddie67 is right on this.
Supernovas are even designated by when their light reaches Earth
[e.g., SN 1987A, Tycho (SN 1572), Kepler (SN 1604), etc.]
Note that Wikipedia has the Vela Supernova (nebula) remnant lying at approximately 1000 LY away.
It is rather the Vela pulsar which is estimated to be approximately 800 LY away. This discrepancy may be due to different calculation approximations and/or to different average (not necessarily constant) redshift velocities of the pulsar and remnant nebula.