Bright new nova in Sagittarius

Affiliation
American Association of Variable Star Observers (AAVSO)
Mon, 03/16/2015 - 15:31

Note: this post was originally called "Requesting monitoring of bright new nova in Sagittarius"

Hello! A few weeks ago I put up a post requesting the continued monitoring of two novae (Sco and Sgr 2015), and your observations have been (and will continue to be) invaluable to us. So I first wanted to say thank you! 

As you may or may not have heard a new nova has been reported in Sagittarius (http://www.astronomerstelegram.org/?read=7230); the most recent observations indicate that it is very bright (magnitude ~5.8) and it is still unknown whether it will continue to become even brighter! We are currently scrambling on our end to try to organize observations in the radio and X-ray and it would help us tremendously if you guys could provide optical coverage. We can use what we learn about the optical evolution of the nova to inform other types of observations, as well as generating a beautiful light curve.

 

Thank you for everything!

Tom Finzell

 

Affiliation
Variable Stars South (VSS)
First spectrum

Hi all,

I have taken a low-resolution (R=260, 150 l/mm) spectrum of this new nova.  The spectrum appears to be that of a Fe II nova shortly after maximum.  Prominent lines of Fe II are already showing at 4924-5018-5169 and 4491-4629.  Strong P-Cygni profiles evident; at this low resolution the ejecta velocity appears in the region of 1400 km/s (+/- 250 km/s).

I'm currently collecting higher-resolution (1800 l/mm, R=c.8000) data of the H Beta region and redwards, including the iron forest around 4924-5018-5169, so should get a much better velocity calculation from that.

Cheers

Jonathan

 

Affiliation
American Association of Variable Star Observers (AAVSO)
Sequence for Nova Sgr 2015 No. 2

I issued Alert Notice 512 before the comparison star sequence for Nova Sgr 2015 No. 2 was ready and available. I apologize sincerely to the AAVSO Sequence Team and to our observers for this error! A sequence will be made available via VSP as soon as possible, and a message will be posted here.

Apologies,

Elizabeth Waagen, AAVSO HQ

Affiliation
American Association of Variable Star Observers (AAVSO)
Comp stars for Nova Sgr 2015 No. 2

Regarding a sequence for Nova Sgr 2015 No. 2, a binocular sequence is being worked on. However, you can find comparison stars now using VSP and requesting an 'a' or 'b' scale chart.

Good observing!

Elizabeth

Affiliation
American Association of Variable Star Observers (AAVSO)
Need help on Spectra 200 spectrum

I need assistance on calibrating the Spectra 200.  The spectrum below is of PNV J183657-285542.

I'm using linear calibration, but I can't identify the peak at 7433. I assume my calibration is off.   I did a linear calibration on  del car, and the resulting 23.8 A/pixel is what was expected given my configuration.  Do I need to do a 2nd or 3rd order calibration? Or other suggestions?

Affiliation
Variable Stars South (VSS)
Hi Gordon,
Yes, your

Hi Gordon,

Yes, your calibration is off a bit.  The peak to the right is H alpha at 6563; the peak to the left (in the middle of the little forest of iron lines) is H beta at 4861.  These should be enough for you to do a linear calibration, which is all you really need.

BTW, I think you are using a Staranalyser 200 not a Spectra 200.

Cheers

Jonathan