Talk:GRB 090423

Supernova

Its still debated whether grbs all come from supernova. Thus the statement that this confirms the births and deaths of stars at that epoch is debatable. —Preceding unsigned comment added by Esheldon (talk • contribs) 20:42, 25 April 2009 (UTC)

"a few degrees west of eta leonis"

Re: the citation needed tag here, could this statement on where it is (or was) located be referenced by the coordinates given in this article? They do seem to suggest it's not far from Eta Leonis. - filelakeshoe 21:06, 30 April 2009 (UTC)

It's not the oldest known anymore (aka new material)

Could someone work out something from this? Thanks. —Matěj Grabovský (talk) 20:51, 12 June 2009 (UTC)

Erm... GRB 090423 is indeed the oldest known object. It says so in the article you've linked to: "Known as GRB 090423, the object is at least 200 million years older than the previous record-holder." --Cryptic C62 · Talk 20:59, 12 June 2009 (UTC)

Citation overkill

Too many citations, especially when you cite sources claiming that it is the oldest. A few is enough, 9 is too many. Brambleclawx 01:24, 4 March 2010 (UTC)

Some of the citations used actually contains data to back up the observations done. It was copy-edited to this state, I'm sure it was for the best intention of all the editors involved with the article. --TitanOne (talk) 12:20, 4 March 2010 (UTC)

Still, 9 citations just to prove that it is the furthest object ever seen? Brambleclawx 00:10, 5 March 2010 (UTC)

That this is the most distant object ever observed is an extraordinary claim, so it definitely needs multiple citations from distinct sources. As I see it, there is nothing to be gained from reducing the number of citations so long as each one is from a different research team / organization. --Cryptic C62 · Talk 18:27, 10 March 2010 (UTC)

Alright then. I will leave this as is, since I would have no idea which references to keep and which to discard anyways. Brambleclawx 22:42, 10 March 2010 (UTC)

GA Review

This review is transcluded from Talk:GRB 090423/GA1. The edit link for this section can be used to add comments to the review.

Reviewer: Cryptic C62 · Talk 23:16, 12 March 2010 (UTC)

Hi there! Just so you know where I'm coming from, here's a disclaimer on my connection with GRBs: I am not an astronomer or a scientist of any sort. I collaborated with Jehochman and Daniel Perley on Gamma-ray burst (FA), wrote History of gamma-ray burst research, started List of gamma-ray bursts, and wrote GRB 970508 (FA), GRB 050709, and GRB 970228. I also did some work on this article when it was first created. I have long dreamed of Wikipedia becoming an excellent resource on GRBs with multiple FAs and GAs, and as such I would definitely enjoy promoting this to GA. However, I also have very high standards for how the information should be presented, so don't think you're getting off easy here! If you think any of this presents a conflict of interest that would prevent me from taking an impartial stance on this nomination, let me know and I will kindly let someone else review it.

Alrighty, let's start by working on the obvious issues, then we'll take a look at the GA checklist. My initial concerns with the article:

• Although it is sometimes lumped in with "astronomical objects", it is more correct to describe a gamma-ray burst as an "event", not an "object." When the term "object" is used in the realm of gamma-ray bursts, it usually refers to the host object as detected by its afterglow. Also, GRB 090423 should usually be described in the past tense: "GRB 090423 was a gamma-ray burst..." except when discussing its current significance "GRB 090423 is the current record holder.
• Simply saying "the afterglow" is insufficient in most cases (except when referring collectively to multiple afterglows in different wavelengths, such as GRB 970228). The article should specify which wavelength it is referring to, even when a specific frequency is given: "The observation of GRB 090423 by CARMA was taken at a frequency of 92.5 GHz. While the afterglow was not detected...". Radio? Infrared? Optical? Ultraviolet? X-ray? This is also true for image captions. Does the infobox image show the optical afterglow or something else? Is the second image an artist's conception, the initial detection in gamma rays, or an afterglow?
• The article should contain a Characteristics section. I also suggest splitting off a Discovery section if you can get enough information, but I wouldn't consider it mandatory. When writing GRB 970508, I had trouble deciding how to divvy up the massive amount of information for the burst. What Wronkiew and I eventually worked out was this: The Discovery section explains what a GRB is and gives the initial information for the burst (time, location, which instruments detected it). The Observations section discusses any observations and early reports that made significant changes in our understanding of the burst (observations in different wavelengths). The Characteristics section discusses statistics and conclusions drawn from those observations (light curve, peak magnitude, energy output, and beaming).
• The Significance section should be renamed so as to indicate what the significance. In this case, I would suggest something like Distance or Distance and age or something. Up to you.
• I would also like to see a section for the host galaxy. I realize that the burst was probably too far away for astronomers to be able to detect any host galaxy, but you can be damn sure that they tried! I would be very surprised if you were unable to find any articles discussing the host galaxy.
• The Observation history table seems unnecessary to me. Easy rule of thumb: If an observation is notable enough to be mentioned in the article, it should be discussed in the prose. If it is not notable enough to be discussed in the prose, there is no point in mentioning it in a list. Also, the current table seems to be little more than a hodge-podge of information without really giving a clear picture of the timeline of the observations. My !vote is to get rid of it.
• The lead needs some help. First, it should explain what gamma-ray bursts are before trying to explain why this one in particular was significant. Second, all information present in the lead should also be present elsewhere in the article. The second paragraph and the phrase "That the speed of light is finite also means that GRB 090423 is also the earliest object ever detected." are not present in the body of the article. Third, "GRB 090423 provides a unique tool for studying the early universe, as few other objects are bright enough to be seen with today's telescopes." is not accurately written. I can think of plenty of objects that are bright enough to be seen with today's telescopes: the sun, for instance.
• The direct quote in Significance should be followed by a citation.

I'll get nit-picky once these issues are addressed. --Cryptic C62 · Talk 23:16, 12 March 2010 (UTC)

Distance: 13 GLy?

This seems to be inconsistent with: http://upload.wikimedia.org/wikipedia/commons/thumb/b/bd/Velocity-redshift.JPG/250px-Velocity-redshift.JPG (from the Wikipedia page on Hubble's Law). Using this graph and Hubble's law (with H = 67.9), I get a distance of 9.3 Gpc / 30 GLy approx. This is still confortably within the confines of the observable universe, see http://en.wikipedia.org/wiki/Observable_universe — Preceding unsigned comment added by 217.169.229.156 (talk) 09:00, 29 July 2013 (UTC)

You are correct, I've made the edit. It seems light travel distance and proper distance were mixed up before. See also http://en.wikipedia.org/wiki/Observable_universe#Most_distant_objects 82.139.86.180 (talk) 01:46, 8 November 2014 (UTC)

For additional reading, see http://en.wikipedia.org/wiki/Comoving_distance 82.139.86.180 (talk) 02:05, 8 November 2014 (UTC)

Come to think of it some more, maybe we shouldn't mention distance at all in terms other than redshift. It makes very little sense to talk about the distance between the planet earth and the originator of this GRB, when the two never co-existed in the same time. 82.139.86.180 (talk) 02:14, 8 November 2014 (UTC)