B[e] star IRAS 17449+2320: call for observations

[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

[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

[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.

[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 2032 times

And made a hires (R~17000) attempt earlier:

iras_17449_2320_hires.png (17.95 KiB) Viewed 2032 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.

[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

[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_DataBase/B_e/IRAS17449+2320.htm

François

[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

[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

[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.

[Tim Lester]

Spectrum for 2017-06-04 at R = 9000.

iras17449+2320_20170604_163_tlester.png (16.27 KiB) Viewed 1954 times

Tim