Sunday, January 26, 2014

Supernova in Cigar Galaxy

With a clear night finally at hand, I took the opportunity to image the new Supernova, SN 2014J, in the galaxy M82 ... along with every other amateur astrophotographer!

This supernova was discovered a week ago during a practical class session on CCD camera usage by astronomy teacher Steve Fossey and his students at the University of London Observatory. After noticing an unexpected star in the images, they hurriedly took a series of images with different filters and an alternate telescope to double check the result before reporting their finding. Wow, in this era of automated surveys by robotic telescopes, it is very motivating to read about a supernova discovery made in this manner.

The supernova has been confirmed as a Type Ia based on spectroscopic analysis by Yi Cao at Caltech. This type of supernova results from material from a companion star accumulating on a white dwarf until the mass of the latter reaches a critical limit. Due to the consistency of this mechanism, such supernovae go off with a predictable absolute magnitude and can therefore be used as a so called "standard candle" used to estimate distances. In this case, the host galaxy, M82, is known to be about 11.4 million light years distant.

Since I had my narrowband filter-wheel loaded, I imaged in luminance and H-alpha (M82 has pretty dramatic structure in H-alpha light)  I composed a false color image using the H-alpha (4x20min) for the red channel and luminance (7x10min) for the blue-green channels. This gave some color contrast between the disk of the galaxy and the tendrils of excited gas glowing in H-alpha that are being blown out from the galactic core. A excellent image by Adam Block, was posted by Phil Plait on his Bad Astronomy blog and shows this emission in much greater detail along with the supernova.

Using the magnitude tool in MaxImDL, I estimate the supernova to be at about magnitude 10.5 in the image taken at 2014-01-27 05:30 UTC. It is predicted to increase in intensity over the next week ... unfortunately for me, so is the cloud cover!

M82/SN2014J - 2014-01-27 05:00 UTC - TMB130SS, QSI-540ws, 12nm HA (4x20min) and Lum (7x10min).

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