I viewed the nova again today (23 Aug 2013), this time through a 120mm ED refractor at 26x and 64x power, as well as with 15x50 binos.
The nova has continued to dim. I spent about a half hour from around 9.00pm to 9.30pm (1300 - 1330UTC) trying to ascertain its brightness by comparing it with nearby stars (around 1-3 degrees away) in the eyepiece of the refractor.
The nova was off-white with a slight creamy-yellow tinge.
The following are my findings:
- It was considerably dimmer than SAO 88664 (mag 5.69)
- It was brighter than SAO 88693 (mag 6.43)
- It was slightly brighter than SAO 88783 (mag 6.21)
I reckon that it was then at around mag 6.0 or mag 6.1
This roughly corresponds with the current reported brightness by other observers as reported on the AAVSO website:
http://www.aavso.org/lcg/plot?auid=000- ... an=&vmean=
Reports on the spectroscopic and other analysis of the nova may be found here:
http://www.astronomerstelegram.org/
Some interesting findings on this classical nova:
- A pre-discovery image of the star taken on Aug 13.998 UT shows that the progenitor star was then at 17.1 mag. When the nova was discovered by K. Itakagi on Aug. 14.584 UT, it was already at mag 6.8 mag, a rise of 10.3 mag in 14 hours . The nova reached a maximum brightness of 4.3 around Aug 16.25 UT.
(
http://www.astronomerstelegram.org/?read=5304)
- Between mag 17.1 and mag 4.3 is a magnitude difference of 12.8, which means the nova became brighter by 1.31826e+5 times (which I think means
131,826 times) between pre-nova to its brightness peak, using the calculator at:
http://www.1728.org/magntudj.htm
- Gamma rays have been detected from the nova. I wonder what it means?
(
http://www.astronomerstelegram.org/?read=5302)
- It seems that the nova has been estimated to be at a distance of 5.5 kpc (i.e.
17,950 light years, since 1 parsec = 3.26 light years):
http://www.astronomerstelegram.org/?read=5297
If this is correct, then at its brightest at mag +4.3, the nova had an absolute magnitude of -9.4032 (using the calculator at
http://www.1728.org/magntudj.htm). Since our Sun has an absolute magnitude of +4.83, it means that the nova at its brightest was brighter than our Sun by a factor of 14.233 magnitudes or 4.934919e+5 times (i.e. I think it means 493,491.9x). So this nova was visually around
half a million times brighter than our Sun! (This assumes there no was brightness extinction by interstellar dust, etc.) If so, I think this nova is quite super.
Any comments as to the correctness or otherwise of the above conclusions?