Starship Asterisk*

[quote="ssgeo"]After seeing the APOD of the newest supernova a few days ago, I wondered why we only see them on rare occasions. Surely, with the billions upon billions of stars out there in the visible universe, one would think we would see more occurring regularly, like flashbulbs at a rock concert. Why do they seem such rare events?[/quote]
We see a few hundred a year- as events in the Universe they aren't that rare. In a large galaxy with active star formation, like the Milky Way, you might have a supernova every few decades. What attracts attention in a case like this is that the supernova is nearby.

After seeing the APOD of the newest supernova a few days ago, I wondered why we only see them on rare occasions. Surely, with the billions upon billions of stars out there in the visible universe, one would think we would see more occurring regularly, like flashbulbs at a rock concert. Why do they seem such rare events?

[quote="wolf kotenberg"]

When a bomb goes off here on the ground, an explosion is defined by a pressure wave traveling at a specific speed or above. What does an explosion in space " feel like " ?[/quote]
Heat....and radiation (like the victims of Hiroshima felt).

I have a question. When a bomb goes off here on the ground, an explosion is defined by a pressure wave traveling at a specific speed or above. What does an explosion in space " feel like " ?

[quote="Chris Peterson"][quote="biddie67"]Is the designation of "PTF 11kly" a permanent label? How did the "kly" part get added to the label - does it have any particular meaning other than possibly the order in which the SN was discovered?[/quote]
The formal IAU designation (using the normal nomenclature) is [b]SN 2011fe[/b]. The early name of PTF 11kly was simply a temporary designation, presumably using an internal system of the Palomar Transient Factory.[/quote]

Thanks, Chris. Doing a google search on the IAU that you mentioned above (i.e., iau naming conventions), I found a couple of websites that explained the naming pattern.

In the credit to this APOD it names 'B J Fulton' and that he/she is apparently connected with the LCOGT but there is no direct link to any further information on him/her. I think it is interesting to know a bit more about the people named in APODs so I checked the LCOGT website where I found that there was no B J Fulton listed under the LCOGT staff. However, in a report about the supernova in the website I came across this "We were very lucky that BJ Fulton, another member of the LCOGT astronomy team was able to stay up into the small hours of the Californian night to snap some vital and early observations of PTF 11kly". Seeing that B J Fulton was considered valued enough to be named in the credit to the APOD I find it odd that he/she is not listed under the LCOGT staff. Perhaps there is a privacy reason.

The detection of the supernova so early on is fascinating.

[quote="Ayiomamitis"]
Using differential photometry, I have a mean estimate for the magnitude of [b]13.290 (+/- 0.003)[/b] using GSC 3852:1108 (mag 11.7) and GSC 3852:1069 (mag 11.9) as comparison and check stars, respectively. [/quote]

According to [b]AAVSO Alert Notice 446[/b], we have:

Aug 26.1965 - mag 13.4
Aug 26.8747 - mag 13.118

[b]Aug 26.7708 - mag 13.290[/b] (my estimate from above) and perfectly in line with the reported magnitudes from the AAVSO bulletin.

Credit: Anthony Ayiomamitis
Source: http://www.perseus.gr/Astro-DSO-Supernovae-SN2011fe-20110826.htm

[img2]http://www.perseus.gr/Images/dso-supernovae-sn2011fe-20110826.jpg[/img2]

Using differential photometry, I have a mean estimate for the magnitude of [b]13.290 (+/- 0.003)[/b] using GSC 3852:1108 (mag 11.7) and GSC 3852:1069 (mag 11.9) as comparison and check stars, respectively.

Please note that the magnitude estimates for these two stars are accurate to a single decimal digit and which makes my estimate (13.290) slightly questionable.

Ursa Major is rather low in the sky and I went after M101 about 15 minutes before official darkness (for whatever its worth).

Anthony.

[quote="biddie67"]Is the designation of "PTF 11kly" a permanent label? How did the "kly" part get added to the label - does it have any particular meaning other than possibly the order in which the SN was discovered?[/quote]
The formal IAU designation (using the normal nomenclature) is [b]SN 2011fe[/b]. The early name of PTF 11kly was simply a temporary designation, presumably using an internal system of the Palomar Transient Factory.

[quote="biddie67"]Is the designation of "PTF 11kly" a permanent label? How did the "kly" part get added to the label - does it have any particular meaning other than possibly the order in which the SN was discovered?[/quote]

I keep reading it as "likely".

Wow! you can't even see the star before the Nova! 8-) [img2]http://newscenter.lbl.gov/wp-content/uploads/ptf11kly_arrow-1023x578.jpg[/img2]I loved the video! :D 8-)
[youtube]http://www.youtube.com/watch?v=5YZkAoR3WLE[/youtube]

This is a really interesting APOD with great links! Congratulations to the PTF network!

Is the designation of "PTF 11kly" a permanent label? How did the "kly" part get added to the label - does it have any particular meaning other than possibly the order in which the SN was discovered?

I should have added that this is a brilliant APOD. Talk about being up to date and aware of the latest developments! Where is the clap,clap, clap smilie?

Ann

[b][i] http://asterisk.apod.com/viewtopic.php?f=31&t=25050 [/i][/b]

It's the Palomar Transient (not Transit) Factory.

Please note the blue color of the supernova, typical of supernovae of type Ia. Bear in mind, too, that the galaxy, M101, is itself very blue as galaxies go.

Ann

An APOD from a two day old event. It can't hardly get any more up-to-date, or fresher than that!

[url=http://apod.nasa.gov/apod/ap110826.html][img]http://apod.nasa.gov/apod/calendar/S_110826.jpg[/img] [size=150]A Young Supernova in the Nearby Pinwheel Galaxy[/size][/url]

[b] Explanation: [/b] A nearby star has exploded and telescopes all over the world are turning to monitor it. The supernova, dubbed PTF 11kly, was discovered by computer only two days ago as part of the [url=http://www.astro.caltech.edu/ptf/]Palomar Transient Factory[/url] (PTF) sky survey utilizing the wide angle 1.2-meter [url=http://www.astro.caltech.edu/palomar/oschin_telescope.htm]Samuel Oschwin Telescope[/url] in California. Its [url=http://www.astronomerstelegram.org/?read=3581]rapid recovery[/url] makes it one of the supernovas caught most soon after ignition. [url=http://newscenter.lbl.gov/feature-stories/2011/08/25/supernova/]PTF 11kly[/url] occurred in the [url=http://apod.nasa.gov/apod/ap110415.html]photogenic[/url] [url=http://apod.nasa.gov/apod/ap091230.html]Pinwheel[/url] [url=http://apod.nasa.gov/apod/ap090414.html]galaxy[/url] ([url=http://apod.nasa.gov/apod/ap060302.html]M101[/url]), which, being only about 21 million [url=http://chandra.harvard.edu/photo/cosmic_distance.html]light years[/url] away, makes it one of the closest supernovas seen in decades. Rapid follow up observations have already given a clear indication that PTF 11kly is a [url=http://en.wikipedia.org/wiki/Type_1a_supernova]Type Ia supernova[/url], a type of [url=http://en.wikipedia.org/wiki/White_dwarf]white dwarf[/url] detonation that usually progresses in such a standard manner than it has helped to calibrate the [url=http://apod.nasa.gov/apod/ap061224.html]expansion history[/url] of the entire universe. Studying such a close and young [url=http://www.youtube.com/watch?v=5YZkAoR3WLE]Type Ia[/url] event, however, may yield new and unique clues. If early indications are correct, [url=http://blogs.discovermagazine.com/badastronomy/2011/08/25/astroalert-type-ia-supernova-in-m101/]PTF 11kly[/url] should brighten to about visual magnitude 10 in the coming weeks, making it possible to monitor with even moderately sized telescopes.

[b][table][tr][td=left][url=http://asterisk.apod.com/discuss_apod.php?date=110825]<< Previous APOD[/url][/td][td=center][url=http://asterisk.apod.com/viewforum.php?f=9]Discuss Any APOD[/url][/td] [td=right][url=http://asterisk.apod.com/discuss_apod.php?date=110827]Next APOD >>[/url][/td][/tr][/table][/b]