AAVSO Alert Notice 392:
Supernova 2008hy in IC 334
December 8, 2008
Further to CBETs #1608 (Puckett and Langoussis; Daniel W.E. Green, editor) and #1610 (Dennefeld et al., and Yamanaka et al.) the supernova SN 2008hy has been identified as a Type Ia supernova, and is believed to be near maximum light (V=14.3 on 2008 Dec 07.13, JD 2454807.63; T. Orff, reported by Puckett and Langoussis). The object is located approximately 100 arcseconds NNE of the center of IC 334.
Independently obtained spectroscopy of the supernova by Dennefeld et al. (2008 December 07.95, obtained at Haute Provence Obs.) and Yamanaka et al. (2008 December 07.8, obtained at Higashi-Hiroshima Astron. Obs.) both indicate the supernova is of Type Ia, no more than a week after maximum light.
A comparison star sequence is not yet available, but there are several Tycho stars within 10 arcminutes of the supernova. Please clearly identify all comparison stars used. Observers are asked to obtain filtered data if possible, with B, V, and Ic filters preferred.
Supernova 2008hy is located at the following coordinates:
RA: 03 45 08.45 , Dec: +76 39 55.5 (J2000)
Finder charts for this supernova may be plotted by entering the coordinates above into VSP:
http://www.aavso.org/observing/charts/vsp/
It is advisable to check the “Use DSS Image” option so that IC 334 is included on the chart.
Please
SUBMIT OBSERVATIONS TO THE AAVSO with the name “SN 2008hy” (AUID 000-BJJ-253).
Information on submitting observations to the AAVSO may be found at: http://www.aavso.org/observing/submit/
Filed under: AAVSO Alerts
S And was used to prove that M31 was NOT a large external galaxy. Those who favored the hypothesis that “spiral nebula” were not similar systems to the Milky Way cited the conclusion that S And would have to be vastly more luminous than any other stellar variable known at the time if M31 were at a large distance. What was not known to them was that S And was a Type Ia Supernova, thus it WAS much more intrinsically luminous than anything that had been seen before. There was no context in the 1920s that would have allowed SN to be understood. M31 was shown to be external when Edwin Hubble was able to identify Cepheid variables in its disk.
Are there any test cases with objects where we know what they should look like (i.e., some verification 🙂 )?
I imagine you could so this with a distant type Ia supernova if you had a model of the supernova and before and after pictures taken with the same camera…?
“The two most dramatic supernova explosions occurred in the 11th century. A supernova in 1006 – you can see its modern remnant above – is the brightest star ever recorded, appearing in the records of China, Egypt, Iraq, Italy, Japan, and Switzerland. There’s even some thought that a rock painting by the Hohokam, a Native American tribe in what is now Arizona, represents the first recorded sighting of a supernova in the Americas. The various observations even allow us to pinpoint what specific type of supernova it was. In all likelihood, it was a Type Ia supernova, which for a few weeks burn as brightly as five billion suns. Astronomer Frank Winkler explains that we can work out from that supposition: “By knowing this distance and the standard luminosity of Ia supernovae, we can calculate, in retrospect, just how bright the star must have appeared to 11th century observers.
Remember that in our universe relative motion is an actual, literal phenomenon. If something is moving relative to you, you will observe that time passes more slowly in the reference frame of the moving object than it does in your own reference frame. That’s special relativity. There are certain astronomical phenomena that have very well defined evolutions over time. Type Ia supernovae are the best example. If we look at a distant galaxy where a type Ia supernova as occurred, and measure the characteristics of that type Ia supernova, we can come up with a graph that tells us how time is passing in that distant galaxy relative to us. When we do just that, we find that time is *not* passing in distant galaxies at a rate that’s consistent with special relativity. In other words, those galaxies are not actually moving relative to us. Instead, we find that the rate at which time passes there is virtually perfectly consistent with the predictions that emerge from the equations of metric expansion. On the large scale, basically everything in the universe is at rest relative to everything else — where cosmologists define anything moving more slowly than about a million meters a second to be “at rest,” because they’re concerned with larger things.
When the right type of supernova (type Ia supernova) explodes, the actual collapse releases 1–2 × 10^44 joules which can temporarily cause the supernova to become brighter than the galaxy that it is in. We can certainly see these sort of things go off in distant galaxies. A supernova going off within our own galaxy could do damage to us if it was 100-3000 light years away depending on what type of star causes it.