New ?nova in Carina at mag ~7.9

[Terry B]

A new "star" has been reported in Carina. I have copied the report email below by Sebastian Otero. Maybe someone with clearer skies than be would like to try to get an image and measure it's brightness.

A possible nova in Carina has been reported by the Pi of the Sky team at the approximate position 11 13 54 -61 14 00 (J2000.0).
This is near the AG Carinae field, so I have updated the AG Car chart on my website so it can be used as a finder chart or binocular chart since this nova seems to be bright:
http://ar.geocities.com/varsao/Carta_HD_95687.htm

While preparing the comparison sequence I found that three of the "natural" comparison stars at mag. 10 are actually variable (GCAS stars) so they had to be omitted from the sequence.
All variables (according to analysis of ASAS-3 data) are included in the telescopic chart at:
http://ar.geocities.com/varsao/Carta_Nova_Car_2008.htm

[Ian Robinson]

Nothing but clouds here ....

[AlexN]

damn clouds...

[bmitchell82]

If only i had the astro gear to take the photo! over here in perth its been quite nice in the evening/early morning

[bojan]

Photo is here...
http://www.iceinspace.com.au/forum/showthread.php?t=38618

[bojan]

This was supposed to be a curve.. However Melbourne's weather interfered and I have only points so far :sadeyes:.
Still better this than nothing.
Magnitude estimates are visual, measured on 10x stacks with IRIS on G-channel only.
I hope for couple of consecutive clear nights in the near future.

[Ian Robinson]

Typical exponential decline.

[bojan]

Yes.. I will be able to monitor it with current setup all the way through January next year.. until it fades to mag 15. After that I will need LP filters or darker site...

[Ian Robinson]

May not go that faint , any info yet on the prenova progenator star's brightness yet ?

My 10" is still in pieces waiting on my flocpaper to arrive. Hopefully I'll have the stuff before Xmas , then I make some minor mods to the Orion cell and reassemble , collimate see how it performs.

What other variables and novae and supernovae are you monitoring at present ?

[bojan]

Actually, this is my first nova that I am monitoring properly :-) Before this my equipment was not quite up to the task (EQ6 with GoTo)
As far as progenitor is concerned, I saw Avandonk's shots taken before outburst.
He caught stars much fainter that mag 15 and there was no trace of anything on them at nova's position.

[Terry B]

I've been able to take some images and measure this nova. It pokes it's head above my trees at about 2300hrs now.
The image is through a "V" filter on 18/12/08. It's been cloudy over the last few nights so no more measurements have been possible.
The little open cluster in the image is NGC 3603.
North is up and west to the right. Taken with an ST9E with 30 sec exposure. The field is 19arcmin square.

Date B V
14/12/2008 10.752 10.234
15/12/2008 10.601 10.015
16/12/2008 10.726 10.168
17/12/2008 10.715 10.133
18/12/2008 10.906 10.293

[Rob_K]

Last night was the first real chance I've had to image this one. The nova appears to be very reddened and I wouldn't want to try to estimate magnitude.

Shot at 200mm tracking with RA drive on EQ1, but focus was out & I reduced size a bit before I cropped to make the shot a bit more presentable! :P

Cheers -

[Terry B]

Interesting image Rob.
I haven't tried to image it through red or IR filters so don't know how red it is. It is pretty bright in blue on my images with a B-V of about 0.7.
I compared your image to mine. The image scale is amazingly different. Your image is west up and north to the left compared to my north up. The bright blurry star next to the "x" on your magnified image is the NGC 3603 that is on the edge of my field. My image is slightly smaller than your magnified part.:D

[Rob_K]

Hmmm yes Terry, my shots are pretty wide - just shooting through a camera lens. The 'magnified' inset is about actual pixel size shooting at 200mm in Small image size.

Colours is a can of worms, LOL! My shots are unfiltered and no doubt if our eyes were good enough to see dimmer objects & pick up colour, then we would see this nova as a pretty reddish-pink, much as in my shot! That's all I need to know - such a simple soul!! :P :rolleyes: I imagine that the colours in my shot are enhanced by the 'defocusing' (er, out of focus!) and the relatively short exposures.

Cheers -

[bojan]

Terry, I hope you do not mind, I used your numerical data and updated the graph.. We are quite close in our estimates :-)

[bojan]

More details on Nova Carinae here:
https://lists.ipac.caltech.edu/pipermail/ned-helpdesk/Week-of-Mon-20081124/002781.html

[avandonk]

Found an image on APOD pre nova here
http://apod.nasa.gov/apod/ap080326.html

Below are two images aligned with RegiStar. One from my image and the Apod image. The faint smudge looks like the progenitor star.

Bert

[bojan]

Bert, yes, it is barely visible... just a bit above the noise level... It is not easy to be sure, if only we have a better resolution APOD image..

[Terry B]

I don't think it is the progenitor star. I've attached a DSS red image with the position of the nova marked. There is no star visible and this image shows stars down to at least mag 19.

[Terry B]

Your doing well. Apart from Xmas night when I was preoccupied I've had cloud since the 18th.:mad2:

[Rob_K]

Impressive work Bojan! :thumbsup: I notice that AAVSO have a light-curve analysing tool available for download on their website:
http://www.aavso.org/data/software/magplot.shtml

Cheers -

[bojan]

Hi Rob, thank you for your kind words :-)
However, it is just everyday activity, nothing much more :-)

Below is updated curve with tonight's measurement...

[bojan]

After a short break...
Light curve update, again.
It is still quite bright (mag 12)

http://grb.fuw.edu.pl/pi/var/catac/nova081125.htm
http://www.aavso.org/cgi-bin/lcg.pl?...&bband=on&v=on

[Terry B]

I've also been following this. My data is on the AAVSO but here is the summary. It's cloudy tonight so no update today.
Add it in if you like. :)
Date B V
14/12/2008 10.752 10.234
15/12/2008 10.601 10.015
16/12/2008 10.726 10.168
17/12/2008 10.715 10.133
18/12/2008 10.906 10.293
28/12/2008 11.741 11.222
13/01/2009 12.218 11.710
14/01/2009 12.238 11.791
15/01/2009 12.309 11.841
18/01/2009 12.418 11.964
23/01/2009 12.588 12.071
24/01/2009 12.512 12.086
25/01/2009 12.659 12.211
26/01/2009 12.604 12.199

[bojan]

Updated with Terry's results.
There is a constant difference between two of us (systematic error), which means we are both very consistent in methodology.
Once corrected for this, our results will be spot on :-)