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urgent request for spectroscopic observation

Dauban Survey's picture
Dauban Survey
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Joined: 2011-07-07

Good evening,

With a friend we are conducting a photometric survey in the Milky Way. This week we discovered what looks like an unknown eruptive or cataclysmic star in outburst. Its position:

18 40 29.13 -27 09 59.3 (J2000.0)

A field image can be seen here: http://www.aspylib.com/alerts/2013-09-23/follow-up_25Sep2013/imageRTarot_25Sep2013.PNG

Measurements in BVRI filters show it is clearly blue. We measure its V magnitude around 13.4 whereas all catalogs indicate much weaker V values (V=15.9 derived from UCAC-3, V=16.4 in YB6 and V=17.3 derived from CMC14).

We are monitoring the star photometry with telescopes in different locations to cope with bad weather. So far, so good..

Unfortunately, we are not equipped to measure its spectrum! We fear we will not manage to find out the variability type without one. So we're desperately looking for some help..

Thanks a lot

Jerome Caron

mail: jerome_caron_astro at ymail.com

web: http://www.aspylib.com/newsurvey/survey.html

another field image
Dauban Survey's picture
Dauban Survey
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Joined: 2011-07-07
Spectra of ?Dwarf Nova
TCB168's picture
TCB168
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Joined: 2010-07-26

Dear Jerome

I took a spectra of your star last night 29/9/13. I didn't waste too much time on it so the S/N isn't great~ about 15.

It just shows a blue continuum with a slight Hb absorption. This would be consistent with a dwarf nova in outburst.

Terry

Great!
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Dauban Survey
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Joined: 2011-07-07

Dear Terry

Great! Thanks so much! You're the first one to take a spectrum :-)

I made a couple of pages showing the results obtained with your data:

http://www.aspylib.com/newsurvey/alert_23Sep2013_eng.html

http://www.aspylib.com/newsurvey/survey.html

I also posted the link on the spectro-l yahoo mailing list, for some people to comment.

Clear skies

Jerome

contacting T.Bohlsen ?
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Dauban Survey
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Joined: 2011-07-07

Dear Terry, or dear aavso forum-users

I would like to contact Terry Bohlsen to have more information about the spectrum that was taken. Does anyone know how to contact him ?

We have found that the outburst position differs from the known star by about 2 arcsec. Now that it's faiding, we have managed to get images of both stars: the known star, and the "outburst".

At its exact position, we don't see anything on the DSS images. This means that it's actually a large amplitude transient. It could be a nova, but the spectrum does not indicate a nova. Therefore it could be another effect.

Thanks for contacting me (I will post more information on the forum to share the end of the story..)

Here is my email: jerome_caron_astro at ymail.com.

Kind regards

Jerome Caron

RE Contacting Terry B
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TCB168
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Joined: 2010-07-26

Dauban Survey wrote:

Dear Terry, or dear aavso forum-users

I would like to contact Terry Bohlsen to have more information about the spectrum that was taken. Does anyone know how to contact him ?

We have found that the outburst position differs from the known star by about 2 arcsec. Now that it's faiding, we have managed to get images of both stars: the known star, and the "outburst".

At its exact position, we don't see anything on the DSS images. This means that it's actually a large amplitude transient. It could be a nova, but the spectrum does not indicate a nova. Therefore it could be another effect.

Thanks for contacting me (I will post more information on the forum to share the end of the story..)

Here is my email: jerome_caron_astro at ymail.com.

Kind regards

Jerome Caron

Jerome

I will email you

 

Terry

AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484