APOD: Art And Science NGC 918 (2009 Nov 12)

[orin stepanek]

http://apod.nasa.gov/apod/ap091112.html

It is a Beautiful work of art; and I"LL save it in my Wallpaper collection! It must be exciting to find a new supernova. Must be pretty hard too; considering all the galaxies out there and the rarity of supernova activity. 8)

Orin

[kovil]

Hey Oren !

I'm not positive, but if supernovae are named like hurricanes, then SN2009js would mean: as j is #10 in the alphabet, and s is #19; then SN2009js is the 9x26+19 th supernova this year ? the 253rd.

[neufer]

I'm not positive, but if supernovae are named like hurricanes, then SN2009js would mean: as j is #10 in the alphabet, and s is #19; then SN2009js is the 9x26+19 th supernova this year ? the 253rd.

Supernova discoveries are reported to the International Astronomical Union's Central Bureau for Astronomical Telegrams, which sends out a circular with the name it assigns to it. The name is formed by the year of discovery, immediately followed by a one or two-letter designation. The first 26 supernovae of the year get designated with an upper case letter from A to Z. Afterward, pairs of lower-case letters are used, starting with aa, ab, and so on. Professional and amateur astronomers find several hundreds of supernovae each year (367 in 2005, 551 in 2006 and 572 in 2007). For example, the last supernova of 2005 was SN 2005nc, indicating that it was the 367th supernova found in 2005.

Historical supernovae are known simply by the year they occurred: SN 185, SN 1006, SN 1054, SN 1572 (Tycho's Nova) and SN 1604 (Kepler's Star). Since 1885, the letter notation was used, even if there was only one supernova discovered that year (e.g. SN 1885A, 1907A, etc.)—this last happened with SN 1947A. The standard abbreviation "SN" is an optional prefix.

[bystander]

I'm not positive, but if supernovae are named like hurricanes, then SN2009js would mean: as j is #10 in the alphabet, and s is #19; then SN2009js is the 9x26+19 th supernova this year ? the 253rd.

j=10: 26*10 + 19 = 279

[orin stepanek]

Professional and amateur astronomers find several hundreds of supernovae each year (367 in 2005, 551 in 2006 and 572 in 2007). For example, the last supernova of 2005 was SN 2005nc, indicating that it was the 367th supernova found in 2005.

That's pretty good considering there are so many galaxies and stars out there to look for them. 8) That's 1 to 2 per year.

Orin

[neufer]

Professional and amateur astronomers find several hundreds of supernovae each year (367 in 2005, 551 in 2006 and 572 in 2007). For example, the last supernova of 2005 was SN 2005nc, indicating that it was the 367th supernova found in 2005.

That's pretty good considering there are so many galaxies and stars out there to look for them. 8)
That's 1 to 2 per year.

1 to 2 per day

[Axel]

The image is indeed beautiful with its wispy clouds and the elegant NGC 981. But gawd! I'm tired of that downer metaphor "death explosion" or "death star". Those explosions are spilling out the stuff of life - oxygen, carbon, iron - which gave birth to us and who knows what other life-forms. A supernova is like a milkweed pod bursting in the meadow: sure, the pod is now dry and dead but the event is that of giving life, or at least the chance of life.

[apodman]

Okay, cheerful outlook person, you make me quote a verse of my own old lyrics (again) ...

No second rate destiny authored by prophets of doom
Infinity furnishes nature the ultimate womb
And starlight stream on as I watch possibilities bloom

No milkweed in the meadow, I admit, but (dammit Jim) I'm an astronomer blues man, not a botanist.

For anyone left unfulfilled, it's ...

F#m - Bm - F#m - F#m
Bm - Bm - F#m - F#m
Bm - C#m - F#m - F#m

... (written one chord per bar) and the last word of each line is on the first beat of the third bar.

[Indigo_Sunrise]

I'm not positive, but if supernovae are named like hurricanes, then SN2009js would mean: as j is #10 in the alphabet, and s is #19; then SN2009js is the 9x26+19 th supernova this year ? the 253rd.

j=10: 26*10 + 19 = 279

Apologies for being late to the discussion, but where does the number '26' come from??? I understand the 10, with 'J' being the tenth letter, and 'S' is the nineteenth, of course, but I cannot figure out where the 26 is coming from..?

TIA for any lay-person/dumbed-down answers, so that I may understand.....

8)

[neufer]

The image is indeed beautiful with its wispy clouds and the elegant NGC 981. But gawd! I'm tired of that downer metaphor "death explosion" or "death star". Those explosions are spilling out the stuff of life - oxygen, carbon, iron - which gave birth to us and who knows what other life-forms. A supernova is like a milkweed pod bursting in the meadow:

http://antwrp.gsfc.nasa.gov/apod/ap090910.html

<<The Monarch (Danaus plexippus) is a milkweed butterfly (subfamily Danainae), in the family Nymphalidae. Monarch butterflies are one of the few insects capable of making transatlantic crossings. They are becoming more common in Bermuda due to increased usage of milkweed as an ornamental plant in flower gardens.>>

[bystander]

Apologies for being late to the discussion, but where does the number '26' come from??? I understand the 10, with 'J' being the tenth letter, and 'S' is the nineteenth, of course, but I cannot figure out where the 26 is coming from..?

26 letters in the alphabet

Supernova discoveries are reported to the International Astronomical Union's Central Bureau for Astronomical Telegrams, which sends out a circular with the name it assigns to it. The name is formed by the year of discovery, immediately followed by a one or two-letter designation. The first 26 supernovae of the year get designated with an upper case letter from A to Z. Afterward, pairs of lower-case letters are used, starting with aa, ab, and so on. Professional and amateur astronomers find several hundreds of supernovae each year (367 in 2005, 551 in 2006 and 572 in 2007). For example, the last supernova of 2005 was SN 2005nc, indicating that it was the 367th supernova found in 2005.

[Storm_norm]

the image is beautiful.
the question I have isn't so beautiful.

Why choose two lines at 90 degrees to point out the region where the event was happening and not an arrow? or perhaps a circle?

did the originator of the image eliminate the two opposite lines from the cross hairs?

[BMAONE23]

I would imagine that two lines are used so as to cover as little background as possible (a cross hair would obscure some of the galaxy) And a Circle could be misunderstood as a halo around the object. An Arrow would also obscure more of the background and not accurately depict the exact area without touching the object in question, then again causing potential modification to the entire SN image. 2 perpendicular lines both point to an exact object without touching it and cover less of the image without potentially altering the subject SN in the image.

[Storm_norm]

I was thinking the same thing. but that seems kind of trivial after the caption explains that there are stars in the forefront which obviously block our view to what is behind them.

[Freefall74]

Is this NGC 981 or 918???

[apodman]

Why choose two lines at 90 degrees to point out the region where the event was happening and not an arrow?

The stylish semi-crosshairs catch the eye whether it scans horizontally or vertically, and they will not be mistaken for the mouse cursor. Artist's choice.

[Axel]

Is this NGC 981 or 918???

Ha! I was just going to ask the same question. I think it's 918.

[bystander]

Is this NGC 981 or 918???

Good question! NGC 981 is in Cetus not Aries, which is where NGC 918 is.

Supernova 2009js… Another One Bites The Dust!
Universe Today - October 28th, 2009

Far away in the constellation of Aries, in a 14th magnitude barred spiral galaxy designated as NGC 918… a star exploded with enough candlepower to briefly outshine its home. Discovered independently by Lick Observatory Supernova Search (LOSS) and Koichi Itagaki (Japan) on October 11, 2009, this Type II supernova might be hiding in the intergalactic dust, but it isn't hiding from Joe Brimacombe.

[apodman]

NGC 981 is in Cetus not Aires, where NGC 918 is.

I'm from Buenos Aires, and I say kill 'em all!

[bystander]

NGC 981 is in Cetus not Aires, where NGC 918 is.

I'm from Buenos Aires, and I say kill 'em all!

Finger error! I fixed it.

[apodman]

Never happens to me. Notice how my fingers never leave my hands. Figured you'd fix it so I jumped on you while I had the chance. Just slinging without malice again. And I find Johnny Rico humorous in a starched Heinlein sort of way.

[TheBigHenry]

Is it NGC 981 or NGC 918 (as the linked-to sites refer to it)?

[bystander]

Is it NGC 981 or NGC 918 (as the linked-to sites refer to it)?

I'm fairly certain it is NGC 918, even the APOD link galaxy NGC 981 links to the NED entry for NGC 918. And the Sky Factory Deep Sky Catalogue picture for NGC 918 (rotated cw 90) certainly looks more like the APOD than NGC 981.

[TheBigHenry]

Is it NGC 981 or NGC 918 (as the linked-to sites refer to it)?

I'm fairly certain it is NGC 918, even the APOD link galaxy NGC 981 links to the NED entry for NGC 918. And the Sky Factory Deep Sky Catalogue picture for NGC 918 (rotated cw 90) certainly looks more like the APOD than NGC 981.

Thanx, bystander.

[Indigo_Sunrise]

Apologies for being late to the discussion, but where does the number '26' come from??? I understand the 10, with 'J' being the tenth letter, and 'S' is the nineteenth, of course, but I cannot figure out where the 26 is coming from..?

26 letters in the alphabet

Supernova discoveries are reported to the International Astronomical Union's Central Bureau for Astronomical Telegrams, which sends out a circular with the name it assigns to it. The name is formed by the year of discovery, immediately followed by a one or two-letter designation. The first 26 supernovae of the year get designated with an upper case letter from A to Z. Afterward, pairs of lower-case letters are used, starting with aa, ab, and so on. Professional and amateur astronomers find several hundreds of supernovae each year (367 in 2005, 551 in 2006 and 572 in 2007). For example, the last supernova of 2005 was SN 2005nc, indicating that it was the 367th supernova found in 2005.

Okay, so every SN discovered after one designated with a capital letter 'Z' would automatically get multiplied by 26?????
I know I'm not as smart as many of the posters here, but no where in that wiki link does it spell out or clarify the 'equation' for naming SN's. (either that, or I'm even more dense than I thought! )
Try as I might, I don't see how 367 was arrived at, in the final example. Would someone mind spelling it out for me? (In small words - ) And for the record, I understand that 'n' is the 14th letter of the alphabet, and 'c' is the 3rd.

Thank you, once again, in advance.....