Call for monitoring Be stars in the TESS sectors

Re: Call for monitoring Be stars in the TESS sectors

Postby etienne bertrand » Wed Sep 04, 2019 4:37 pm

V1362 Cyg hier
Image
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Re: Call for monitoring Be stars in the TESS sectors

Postby Paolo Berardi » Thu Sep 05, 2019 4:20 pm

Hi all,

very bad weather until now. Yesterday the first opportunity to observe from my site.

BD+47 3302 (BK-924)
Shared spreadsheet note: Fairly active. Some long-term variations and flickers. Strong 5 day period. Possible 14 d period.

Image



HD 201522 (BK-669)
Shared spreadsheet note: Usually very weak double-peaked Halpha (emission below continuum). One spectrum shows strong Halpha though.

Very different from all the other the 2010 spectrum in BeSS database mentioned in the notes.

Image

An attempt to telluric removal.

Spectra are submitted to BeSS.

Paolo
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Re: Call for monitoring Be stars in the TESS sectors

Postby Paolo Berardi » Fri Sep 06, 2019 5:56 pm

Hi all,

yesterday I observed HD 194779 (BK-128). The spectrum R=6000 is centered on h-alpha line.

Image

I don't see noticeable changes during the integration (7 x 960s):

Image

but compared with the last spectra currently in BeSS, it seems that left peak has decreased again.

Paolo
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Re: Call for monitoring Be stars in the TESS sectors

Postby J Labadie Bartz » Fri Sep 06, 2019 6:57 pm

Hi all,

Thanks for the updates! It will be especially interesting to look at all the spectra for HD 194779 together once the TESS data is available since the spectra clearly show disk build up. This star will continue to be an excellent target to observe at least until Sept. 11, which is the date TESS stops observing it and moves on to sector 16.

In the spreadsheet, there is a second tab on the bottom called 'readme' which has some useful information, including the dates that correspond to each TESS sector. Also, I have added notes and priorities for most of the stars that are in TESS sector 16, which TESS beings observing on Sept. 11.

Please let me know if there is anything I can do to improve the spreadsheet to make it easier to use.
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Re: Call for monitoring Be stars in the TESS sectors

Postby Robin Leadbeater » Fri Sep 06, 2019 10:41 pm

Hi Jon,

I have heard via another source that the planned coordinates for sector 16 have been changed because of a problem with scattered light. Does this affect any of the targets from 11th Sept onward ?

Cheers
Robin
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Re: Call for monitoring Be stars in the TESS sectors

Postby Paolo Berardi » Sat Sep 07, 2019 10:41 pm

Hi all,

two observations between clouds...

Again HD 194779. The h-alpha profile shows some changes in one day

Image

V1362 Cyg has reversed V/R peaks compared to Etienne spectrum of sept 3 (also many previous observations in BeSS have V/R < 1). The two broad absorption lines on the right of h-alpha (perhaps CII 6578/6583?) seem to have different radial velocities.

Image

Paolo
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Re: Call for monitoring Be stars in the TESS sectors

Postby J Labadie Bartz » Wed Sep 11, 2019 12:11 am

Hi all,

Robin,

Robin Leadbeater wrote:Hi Jon,

I have heard via another source that the planned coordinates for sector 16 have been changed because of a problem with scattered light. Does this affect any of the targets from 11th Sept onward ?

Cheers
Robin


Yes, this will affect the targets from 11 Sept. onward. I made this list after the announcement of the shifting of sectors 14 + 15, but before the announcement of sector 16. I haven't had time to address this yet, but will work on this soon. Based on the sky maps of the shifted sector position, I believe that this will actually include more Be stars in sector 16 that are currently not marked as such on the spreadsheet. Probably some that are marked on the spreadsheet as sector 16 will no longer be included though (but I expect this will be relatively small, and expect a net increase in sector 16 Be stars). Put another way, sector 16 now covers more of the galactic plan then it did before without much loss of near-galactic-plane sky.

The rapid V/R variability in Halpha for V1362 Cyg and the apparent shift in some absorption lines is still a mystery to me. The RV shift in the absorption lines almost necessarily indicates there is a binary in this system. The rapid Halpha variation and strange Hbeta profile kind of look like some examples of Herbig Ae/Be star line profiles (see the kind of crappy plots here: https://drive.google.com/open?id=1ostVM ... QdweWY6_q2). I have only a passing knowledge of Herbig Ae/Be stars, so I can't say anything qualitative at the moment. However, as far as I know Herbig Ae/Be stars show strong IR/radio excess in the SED and this can be used to separate them from classical Be stars- the SED of V1362 Cyg does not show such excess though (as viewed through Simbad).
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Re: Call for monitoring Be stars in the TESS sectors

Postby etienne bertrand » Wed Sep 11, 2019 11:31 am

V1362 Cyg

Image

Impressive the ray of CII (?) like pablo Berardi say, the radial velocity :
Image
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Re: Call for monitoring Be stars in the TESS sectors

Postby J Labadie Bartz » Thu Sep 12, 2019 8:41 pm

Hi again,

I am working on checking how the sector 16 shift changes the target list. I can not easily do this in an automatic way because the software I used to make the target list does not know about the sector 16 shift and there is no easy way to incorporate that.

So, I am starting with the highest priority candidates that were in sector 16 before the shift, and making sure they are still in sector 16 after the shift.

If you plan to observe a star and are not sure if it is still being observed in sector 16 or not, you can check here by copying the TESS TIC number from the spreadsheet and pasting it in the top input line on this page: https://heasarc.gsfc.nasa.gov/cgi-bin/t ... ess/wtv.py

Sector 16 has started being observed as of yesterday and will be observed until 7th October. Lots of targets that are in overlap regions and are observed in sectors 15+16 and 16+17. The TESS data from sector 14 is not yet available, but hopefully will be soon. As soon as it is available I will let you all know.


Also, another star that on closer inspection seems to show some peculiarities. V2162_Cyg. The Halpha profiles look somewhat strange, and sometimes the Hbeta emission looks shifted relative to the Hbeta line absorption center. I'm not sure what to make of this. Any ideas??
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Re: Call for monitoring Be stars in the TESS sectors

Postby J Labadie Bartz » Sat Sep 14, 2019 4:22 pm

Hi everyone,

So far I've been a bit vague about the goals of this project. My main scientific goal is to select just a few classical Be stars (~4) and monitor them very intensively simultaneous with the TESS observations. The selection process takes a lot of work because it is necessary to go though each Be star and look at KELT light curves, all BeSS data, literature, SEDs, sky images... basically everything, and then choose the ideal few Be stars to monitor. Of course, also having sparse coverage simultaneous with TESS for lots of Be stars is also quite valuable in its own right.

Anyway, for the next two months, V357_Lac = HD 212044 is that ideal star. It is bright (V = 6.6), very active in its photometry (and so is likely to eject mass during our monitoring campaign), variable in all archival spectroscopy, has a firmly established spectral type, and is in two consecutive TESS sectors.

This google drive folder has plots that speak to the beauty of this star for monitoring its variability: https://drive.google.com/open?id=1o0FXb ... eU_nhZ0hg0

This is in TESS sectors 16 + 17, being observed right now from Sept. 11 - Nov. 02.

I plan to use ~80 hours of telescope time to get high SNR echelle spectra for this star with 3-6 observations per night for about 25 consecutive days. The main goal is to closely observe the photospheric lines (mostly He) to measure their variations due to pulsation (and so to understand the geometry of pulsation on the stellar surface), and also variations that happen before/during/after mass ejection (which we can infer from Hydrogen and other metal lines). The hope is that this will help in understanding how Be stars eject mass and what happens at the star-disk interface.

It will be valuable to have as much spectroscopic coverage of this star before, during, and after the 25 days where I will be intensively monitoring V357_Lac. I will probably being the 25 days on Oct. 1. I have made this star the highest priority on the target list spreadsheet, and I encourage anyone who is interested to pay special attention to this star. The higher SNR the better. If you can achieve a SNR of 100 or greater, that would be excellent.

If you are interested in and able to work on this star, please let me know, especially if you have any questions about an observing strategy. What I will request from individuals will depend on how many observers are involved and their setups and locations.

I've been really impressed with the observations lately! Thanks for all the awesome work! I'm looking forward to see how they compare with the TESS data, some of which should be available soon. Also, the TESS mission will be extended past its original 2 year primary mission. It is not yet announced what the observing strategy will be, but I will definitely continue to submit proposals for Be stars with TESS.
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