Page 1 of 3
B[e] star IRAS 17449+2320: call for observations
Posted: Fri Jun 02, 2017 5:46 am
by Francois Teyssier
Steve Shore and his team request spectra of the B[e] star IRAS 17449+2320
AD = 17 47 03.27
RA = +23 19 45.3
Mag V ~ 10
Spectra at all resolutions (R > 500) are welcome
According to Steve, something strange may be going on
Send spectra to francoismathieu.teyssier at bbox.fr for inclusion in the base
Photometry (V Band) should be appreciated
See Steve’s notes in
http://www.astrosurf.com/aras/novae/Inf ... 017-02.pdf
François
Re: B[e] star IRAS 17449+2320: call for observations
Posted: Sat Jun 03, 2017 9:50 am
by Paolo Berardi
Hi François and all,
yesterday I observed the star, starting with 150 l/mm grating (already intalled), then with 1200 l/mm one.
The low-res profile (R ~600):
Mid-res profile (R ~5000):
H-alpha line detail:
Photometry V (it's difficult for me to estimate possible systematic errors, so I did't add the error bars). Left group is related to the low-res spectroscopic observation period, right group to the mid-res one.
Sending all data to your e-mail.
Old observations are stored on BeSS database (with the star name BD+23 3183)
Paolo
Re: B[e] star IRAS 17449+2320: call for observations
Posted: Sat Jun 03, 2017 2:21 pm
by Olivier GARDE
Hi Paolo,
Great spectrum....
I'm not at home for the moment, but when I come back I will try this target with eshel spectrograph.
Re: B[e] star IRAS 17449+2320: call for observations
Posted: Sat Jun 03, 2017 2:56 pm
by Peter Somogyi
Hello,
I've been proactive here a bit, did observe this star since April but seen no emission in the 6700-7000A range (have quite a few non-detections, not including here).
Comparing to Paolo's profile, the Ha-absorption must have changed a bit (R~2600):
- iras17449_2320_20170513_g600.png (12.26 KiB) Viewed 9743 times
And made a hires (R~17000) attempt earlier:
- iras_17449_2320_hires.png (17.95 KiB) Viewed 9743 times
The H-alpha peaks have varied somewhat (~15%) during these 3 x 1800 sec attempts.
Sent the fits to database.
However, for high resolution I'd guess the OH telluric regions and the LI 6707 was mentioned, and that highest resolution required to detect emission. Again, do have a few negative observations, question if needed in the database at all. If not, first I'd do noisy probes (3-4 minutes) and give high exposures when seeing anything.
- Peter
EDIT: the R~2600 was shot on MAY-13, mistake in the image title. Fits sent are correct.
Re: B[e] star IRAS 17449+2320: call for observations
Posted: Sat Jun 03, 2017 3:04 pm
by Peter Somogyi
By the way Paolo, congratulations for the Vmag serie!
I'd like to implement something similar, if possible on a 9x50 finder...
- Peter
Re: B[e] star IRAS 17449+2320: call for observations
Posted: Sat Jun 03, 2017 5:41 pm
by Francois Teyssier
Congratulations for your reactivity and thanks from Steve for the spectra
The spectra can be download from ARAS database :
http://www.astrosurf.com/aras/Aras_Data ... 9+2320.htm
François
Re: B[e] star IRAS 17449+2320: call for observations
Posted: Sat Jun 03, 2017 9:42 pm
by Paolo Berardi
Thank you, I'm glad if our observations were useful in some way.
The plot of single subexposure profiles shows a slight variation of the h-alpha emission R-peak during the observing session (while V-peak was rather stable). I wonder if it's real (so fast changes?).
Peter, I need to improve my photometry practice. Anyway useful, I think, but I have only the V band filter. So, I have to be careful what reference stars colours and sometime is not possible for me in short time. Here I used the Mak 90 scope, SHV-H9 ccd camera and Baader V filter (I extracted the transmission curve, useful to calibrate the low-res profiles flux). Measures on 30 sec exposure time frames.
Paolo
Re: B[e] star IRAS 17449+2320: call for observations
Posted: Sun Jun 04, 2017 8:59 am
by Peter Somogyi
Thank you Paolo for the explanation! That setup with the H9 must be quite powerful!
I will open a thread for this topic on the mailing list soon.
- Peter
Re: B[e] star IRAS 17449+2320: call for observations
Posted: Sun Jun 04, 2017 11:00 am
by Joan Guarro Flo
Buongiorno Paolo, hi Peter,
The graphical comparison of Halpha is very interesting, I think your arguments are very reasonable. What is the integration time of each?
Your work, confirms that a star is very interesting. Congratulations ! It is a real stimulus to observe it.
Saluti tanti, Cheers, Joan.
Re: B[e] star IRAS 17449+2320: call for observations
Posted: Sun Jun 04, 2017 7:59 pm
by Tim Lester
Spectrum for 2017-06-04 at R = 9000.
- iras17449+2320_20170604_163_tlester.png (16.27 KiB) Viewed 9665 times
Tim