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Call for monitoring Be stars in the TESS sectors

PostPosted: Wed Aug 21, 2019 9:38 am
by Robin Leadbeater
A thread to discuss the proposed TESS/BeSS campaign announced by Coralie Neiner on spectro-l.

See also

and Jon's introduction message here

Dear all,

The NASA space photometric mission TESS is observing all types of stars
in the sky, including Be stars. This is a good opportunity to perform
combined spectroscopic and photometric studies, which would help to
understand Be outbursts. TESS changes field of view (called sectors)
every 27 days, therefore we need to concentrate on Be stars that have
rapid outbursts.

Jonathan Labadie-Bartz has put a list of interesting TESS Be targets
together, which is available here: ... edit#gid=0
The following link tells you which sector TESS is observing at what time
(currently sector 15):

It would be great if we could obtain 1 spectrum per night of each Be
target being observed by TESS (during the TESS observations). This means
we would observe the Be targets of one sector for 27 days, then move on
to the targets of the next sector for 27 days, and so on. Ideally what
we need is high-resolution spectra, at least Halpha and if possible full
echelle spectra, but lower resolution spectra are welcome too.

If you wish to participate to this project and you obtain data of the
TESS Be stars, please upload them in BeSS as usual.

Coralie Neiner

Re: Call for monitoring Be stars in the TESS sectors

PostPosted: Wed Aug 21, 2019 9:48 am
by Robin Leadbeater
Paolo Berardi wrote:Thanks Robin!

A lot of target in the TESS Be list...

I think I should have observed HD345122 between July 18 and Aug 15, when TESS was observing the sector 14. Now it is on sector 15. If I understand correctly, we should observe (up to Sept 11) all targets containing the number 15 in the sector field of Be_Star_table.


Yes I agree. From the table there are about 80 in the table for the current field 15. (I am assuming 15/16 for example means the fields overlap and it is in both.) It is not realistic to monitor all of them on a daily basis. Perhaps a a small list of priority targets or an alert system for outbursts detected by TESS so we can concentrate on those stars ?

(Note that not all the stars on the list are in BeSS. For example I measured BD+27 3970 last night. It is listed as Be in SIMBAD but not in BeSS)


Re: Call for monitoring Be stars in the TESS sectors

PostPosted: Wed Aug 21, 2019 5:39 pm
by Robin Leadbeater
Further information from Coralie and Jon posted on spectro-l


Date: Tue, 20 Aug 2019 07:09:43 -0300
From: Jonathan Labadie-Bartz

Thanks Coralie!

If I may chime in, I'd like to point out three stars in particular that lie in overlapping fields in TESS and will be observed for many months up to a year. The BeSS observers have already taken many excellent datasets for these three stars. More spectra taken over the next year of these systems will be very interesting to compare with the relatively long TESS light curve. These stars are lines 73, 74, 75 in the spreadsheet Coralie linked to. I will continue to work on this spreadsheet to make it more user friendly and informative.

It would be a good idea to monitor these at a low cadence over the next year. In particular I like these first two in the list below, which are interesting for different reasons. I'm not sure what to make of the last star in this list, but more data certainly doesn't hurt.

TIC 236785664 = HD_175511
RA = 283.00928 DEC = 59.66706
V = 6.97
Sectors: 14,15,16,17,18,19,20,22,23,24,25,26

Note - Many BeSS spectra from 2001 - March 2019 show normal-looking double-peaked emission at 1.5xContinuum with only slight V/R variations and not much change in intensity. Presumably this disk is being fed at a nearly constant rate. What implications does this have for interpreting the year of TESS data that we'll have? H-alpha measurements at least over this time period will be valuable. Nice and bright.

TIC 233613741 = HD_175863
RA = 283.43629 DEC = 60.01791
V = 7.11
Sectors: 14,15,16,17,18,19,20,21,22,23,24,25,26
Note- Interesting! A BeSS spectrum taken July 23 2019 (near beginning of TESS sec. 14) shows no emission. Spectra between 2001 - 2006 show a strong 3xContinuum disk. All spectra since then (from 2009 to present) show no disk... B4Ve. This will have virtually uninterrupted TESS coverage (save for a ~3 day gap each month or so). From the BeSS spectra this seems like a Be star with a clear on/off valve for its mass loss. Will it turn on and build a disk over the next year? Only one way to find out... This, IMO, is an excellent star to get at least an H-alpha spectrum every week or two if possible. If we notice any signs of emission then we can ramp up the monitoring. Bright enough to work with.

TIC 284563819 = HD_183339
RA = 291.44493 DEC = 58.02729
V = 6.13
B8IVwe or B7IV
Sectors: 14,15,16,17,20,23,26
Note- 17 BeSS spectra from 2008 - 2019 all show H-alpha purely in absorption, and with a rather narrow core, and some narrow lines in the posted echelle spectra. By eye the SED doesn't look like it has any sign of a disk. No obvious signs of variability. This is in some catalogs of chemically peculiar stars. I don't think this looks promising to monitor as a classical Be star.

Best regards,

From: Coralie Neiner
Sent: Wednesday, August 21, 2019 2:36 PM

Hi Robin,

I would think that the best is:

- to follow every night a few very interesting targets (pointed out by Jonathan or outbursting)

- monitor the other targets whenever possible to try to detect an outburst event (and then move that target up in the priority list for more frequent observations)

But note that here we are not necessarily looking for the big outbursts (although that would be great!). Any detected small emission event is interesting to put the photometric variations observed by TESS into context.


Re: Call for monitoring Be stars in the TESS sectors

PostPosted: Wed Aug 21, 2019 10:36 pm
by Robin Leadbeater
Two TESS sector 15 spectra from last night (R~5500)

BD+27 3970 is listed as Be in SIMBAD but is not in BeSS. (BeSS webmaster informed).
H alpha is in emission (FWHM 6.7A) and there is a hint of a W shape profile

bd+273970_20190820_872_Leadbeater.png (17.02 KiB) Viewed 10154 times

EM* MWC 1030/TYC 3178-815-1 shows a very strong single component H alpha emission line (EW -110A, FWHM 3.3A) There is also an unidentified emission line at ~6515A
This is the first high resolution spectrum in BeSS. There is a low resolution spectrum from 20180716 which also shows H alpha in emission at similar EW

tyc3178-815-1_20190820_20180716.png (17.29 KiB) Viewed 10154 times

Both have been uploaded the BAA spectroscopic database and TYC 3178-815-1 has also been submitted to BeSS


Re: Call for monitoring Be stars in the TESS sectors

PostPosted: Thu Aug 22, 2019 3:16 am
by Terry Bohlsen
All are very northern targets so I'm afraid I won't be able to contribute.

Re: Call for monitoring Be stars in the TESS sectors

PostPosted: Thu Aug 22, 2019 9:53 am
by Robin Leadbeater
Hi Terry,

Very true. TESS has been observing the southern hemisphere for the past year and will observe the northern hemisphere for the next year
Not sure what plans there are for TESS beyond 2 years


Re: Call for monitoring Be stars in the TESS sectors

PostPosted: Thu Aug 22, 2019 9:59 am
by Robin Leadbeater
I guess more northerly (or last year southerly) targets may also have the advantage of being observed by TESS for longer due to the increased overlap of segments near the poles.


Re: Call for monitoring Be stars in the TESS sectors

PostPosted: Thu Aug 22, 2019 4:22 pm
by Joan Guarro Flo
Hi Robin,

I've finished the test time to NOU_T and I can try enter in this observations program. I going to start to can try to observe HD193009, field 15 and I try go on observe the list stars, and repite HD175511, HD175863 and HD183339 once a week.., is that correct ?

A question, will BeSS Data Base accept observations of stars nowadays don't are registered in it ? for example HD175511.

Regards, Joan.

Re: Call for monitoring Be stars in the TESS sectors

PostPosted: Thu Aug 22, 2019 4:54 pm
by Robin Leadbeater
Hello Joan,

That seems sensible to me. Keep looking at Jon's spreadsheet. He is updating priorities there. For example based on my spectrum and other information he has dropped EM*_MWC_1030 from the list.

If any targets are rejected by BeSS, email and Coralie will review and add it. (and you can still upload it to BAASDB as well of course)


Re: Call for monitoring Be stars in the TESS sectors

PostPosted: Sun Aug 25, 2019 1:58 pm
by Valerie Desnoux
Hi There

Exciting project to support TESS photometry observations !
I am relaying the infos posted by Oliiver Thizy on the Be star Spectra group on facebook.

If you are already a BeSS observer registered, Olivier can grant you the access. Just go there and request to join.
We use to put there the stars we are observing during an observing session to limit the duplication.