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Name and coordinates
editIt would be useful if someone could find the star's coordinates in the sky, as well as the meaning of the name iPTF14hls. I figured that iPTF=Intermediate Palomar Transient Factory, followed by the year of discovery=2014. It remains to decifer the "hls". -BatteryIncluded (talk) 19:43, 9 November 2017 (UTC)
- The letters follow the traditional supernova naming convention, starting at a, going through the alphabet, then doing the same with two and eventually three letters. They find a lot of supernovae! Lithopsian (talk) 20:05, 9 November 2017 (UTC)
- αJ2000 = 09h 20m 34.30s, δJ2000 = +50° 41′ 46.8″ Lithopsian (talk) 20:07, 9 November 2017 (UTC)
- FWIW - yes - agreed - casual view of relevant reference[1] gives the following => "right ascension, αJ2000 = 09h 20min 34.30s and declination, δJ2000 = +50◦41’46.8”, at an RPTF-band magnitude of 17.716 ± 0.033 ... redshift of z = 0.0344 ... luminosity distance of 156.2 Mpc" [or 509456261.96 light years[2]] - hope this helps - in any case - Enjoy! :) Drbogdan (talk) 20:17, 9 November 2017 (UTC)
- Although the linked pdf does show that information, it appears to be simply an early (or late) draft of the published paper on an internal Caltech wiki. Certainly it is just a re-hashing of the same information in the Nature paper. Possibly it shouldn't itself be considered a reliable reference, as well as being an obvious candidate for linkrot. Lithopsian (talk) 14:54, 10 November 2017 (UTC)
- FWIW - yes - agreed - casual view of relevant reference[1] gives the following => "right ascension, αJ2000 = 09h 20min 34.30s and declination, δJ2000 = +50◦41’46.8”, at an RPTF-band magnitude of 17.716 ± 0.033 ... redshift of z = 0.0344 ... luminosity distance of 156.2 Mpc" [or 509456261.96 light years[2]] - hope this helps - in any case - Enjoy! :) Drbogdan (talk) 20:17, 9 November 2017 (UTC)
I am not familiar with the star's database, but these other names (synonyms) may give us data on the calculated mass and radius: "iPTF14hls was later independently discovered by the Catalina Real-Time Transient Survey as CSS141118:092034+504148 (more recently the event was reported to the Transient Name Server as AT 2016bse).". -BatteryIncluded (talk) 21:53, 9 November 2017 (UTC)
- FWIW - May (or may not) be relevant => "current radius would be >/~ 1017 cm (using the Fe II 5169A velocity of ˚ ≈ 4000 km s−1 111 ), 112 requiring a mass of >/~ 200 M�"[1] - but maybe a worthy reference[1] for a closer view? - Enjoy! :)
- Although there are different names, you won't find many different sources for this object. It was just one of thousands of supernovae until its unusual behaviour was spotted. Lithopsian (talk) 14:54, 10 November 2017 (UTC)
- In page 5 & 6, he goes on to explain 2 methods to calculate the likely radius, and both give quite different results, so he says it is part of the mystery. BatteryIncluded (talk) 22:38, 9 November 2017 (UTC)
- The "radius" of a supernova is quite a tenuous (sic) concept (of a star also, but usually much less so), and probably not one that we ought to be reporting as a single bald number. The radius of a supernova changes dramatically with time, but also at any time has radically different values for different definitions of radius (eg. optical depth, location of particular spectral lines, effective temperature radius, etc.) Ultimately a supernova is an expanding nebula, probably not a remotely spherical one, and not a star any more. The paper discusses it in some detail, including the contradictory results between different methods. Lithopsian (talk) 14:54, 10 November 2017 (UTC)
References
- ^ a b c Arcavil, I; et al. (2017). "iPTF14hls: A unique long-lived supernova from a rare explosion channel" (PDF). Caltech. Retrieved 9 November 2017.
{{cite web}}: Explicit use of et al. in:|author=(help) - ^ Convert megaparsec to light years
Inappropriate photo?
editThe photo currently in the Infobox, captioned "Example of a supernova", actually shows a supernova remnant (SNR 0519-69.0) – rather like a planetary nebula, but bigger. While I grant that this is not wholly incorrect in a technical sense, it seems to me that this is somewhat misleading, as most people's interest is on the Supernova (or not) explosion itself rather than what the remnants may look like some indeterminate time later.
An actual photo of IPTF14hls would of course not be very spectacular, as it would comprise a tiny white dot within a small fuzzy blob, but could we not instead use a photo of SN 1987A soon-ish after detection? {The poster formerly known as 87.81.230.195} 90.200.138.27 (talk) 23:15, 9 November 2017 (UTC)
Done - added "File:Composite image of Supernova 1987A.jpg" - to replace "File:NASA-SNR0519690-ChandraXRayObservatory-20150122-crop.jpg" - as suggested - seems ok - hope this helps - in any case - Enjoy! :) Drbogdan (talk) 03:11, 10 November 2017 (UTC)
(supernova remnant)
- Still a supernova remnant of course, just a much younger one ;) That image is from about 25 years after the explosion, showing mainly ejecta shocked against circumstellar material. Here is an actual image of SN 1987A in the Large Magellanic Cloud, although there are much more photogenic images of supernovae available. SN 1987A is a good one though, because the LMC is thought to be comparable to the host galaxy of iPTF14hls. There are much earlier images of SN 1987A showing mainly light echoes from the explosion which might be considered more representative of a supernova itself, as well as pre-2000 images which show a largely-undifferentiated blob of light. Lithopsian (talk) 15:03, 10 November 2017 (UTC)
- I'm not aware of any public-domain images (or any image!) of iPTF14hls at the moment. It is just a boring blob, after all. However, the original iPTF images are available and I could put together a before/after composite or even something more complex. I don't think there are any licensing or copyright issues, but it would be good to have that confirmed. Lithopsian (talk) 15:24, 10 November 2017 (UTC)
- So I still think this is OK for Commons. Here's the image I created from the raw iPTF frames. Lithopsian (talk) 17:29, 10 November 2017 (UTC)
Possible explanation
editDo supernovas always have to follow a set time? also i see scientists suggesting something https://phys.org/news/2019-11-iptf14hls-variable-hyper-wind-massive-star.html plus i think it might also be that the star did not expend all of it's energy, so could it be just pure chance? — Preceding unsigned comment added by Kiritami (621) (talk • contribs) 18:22, 24 February 2021 (UTC)
- A supernova is a very brief explosion, so the subsequent visible brightness is constrained to drop in a known way. Some variation has been shown for things like interactions with circumstellar material, but nothing that accounts for this object. The paper you linked discusses several of the theories already described in this article, but proposes a new one, so it should probably be added. Lithopsian (talk) 19:52, 24 February 2021 (UTC)