T Tauri stars campaign
2013 : RY Tau V410 Tau
2012 : RY Tau DN Tau DR Tau
|
|
T Tauri stars campaign 2013 : RY Tau V410 Tau 2012 : RY Tau DN Tau DR Tau |
|
|---|---|---|
|
||
| Last update : 01 - 05 - 2013 |
|
Introduction to 2013 Campaign
In 2012, Darryl Sergisson ( University of Exeter) has requested assistance (photometry and spectroscopy) with a campaign of observations of T Tauri stars. Aras observers gathered spectra of RY Tau, DN and DR Tau (see : 2012 campaign).
After reviewing the collected spectra Darryl proposes concentrating efforts on
RY Tau at high resolution ( R > 10000)
V410 Tau at lower resolution (R ~ 2000)RY Tau
"I think that it would be best to concentrate on RY Tau as it is the brightest and allows for high quality spectra from your telescopes. In particular, the data collected so far indicate that a 22 day periodicity may be present, which agrees with other authors. I would like to investigate whether this period is related to a binary period by studying whether there is any periodic variability in photospheric absorption line widths (v sin i). To do this, we would need repeated spectra of RY Tau at a resolution of R = 10,000 or greater, which I note many ARAS observers are able to do. We need to concentrate on a region with reliable photospheric lines, so I think 6400-6600A is good, as before. This also includes Ha which is useful for correlation with accretion. This project does not require standard stars or telluric correction, thus allowing maximum time on target and the highest S/N. The higher the S/N the better for this work, but a minimum of ~30 per 0.5A wavelength step would be sufficient."
V410 Tau
"It would be great if observers with lower resolution spectrographs would monitor another star, V410 Tau which is bright (R = 8.5) and thought to have significant coverage of star spots. We are interested in establishing the surface area coverage, longitudinal symmetry and temperature of star spots on T-Tau stars as they are responsible for variability and are useful diagnostics of magnetic fields. We would like to observe V410 Tau over many rotations (an entire season would be fantastic) at a resolution of R~2000 or greater in the region between 7000-7600A. This includes the TiO band-heads at 7050A which we use as a diagnostic of spot coverage and temperature. (See Webb, Naylor and Jeffries 2002). V410 Tau may be found at 04 18 31.11, +28 27 16.1. These observations will need correcting for system response and telluric absorption. S/N should be as high as possible, ideally >100 per 2A wavelength step."
Targets and procedure
Target for high resolution spectrographs (LHIRES 2400 l/mm, eShel, ...)
Target RY Tau AD (2000) 04 21 57.41 DE (2000) +28 26 35.6 Mag (R) in 2012 9.3 to 10.3 AAVSO Light Curve Resolution 10 000 Range of interest 6400 - 6600 angströms SNR at least 30 per 0.5A wavelength step Purpose of investigation Search for periodic variability in photospheric absorption line widths (v sin i) Flux calibration no Telluric correction no Frequency one every 3 or 4 days Duration Target for medium resolution spectrographs such LHIRES600 l/mm but also eShel if possible
The resolution required by Darryl is higher than the resolution of LISA or Alpy600. The first results will determine whether it is possible to detect changes and meet goals at such a resolution (respectively 1000 and 650)
Target V410 Tau AD (2000) 04 18 31.11 DE (2000) +28 27 16.1 Mag (R) in 2012 8 Resolution ~ 2000 Range of interest 7000 - 7600 angströms SNR > 100 Purpose of investigation Surface area coverage, longitudinal symmetry and temperature of star spots on T-Tau stars as they are responsible for variability and are useful diagnostics of magnetic fields Flux calibration Reference star :
Frequency one per day Duration The entire season from august 2013 to march 2014
Recommandations :
In order to be able to maintain consistency and benefit the most from the data it would be beneficial if the following could be provided for each observation:
Observation details:
• Date/time in UT
• Location
• System details (aperture, instrument used)
• Target and standards observed (Name, HD number or RA/Dec)
How to submit your spectra
Mail your FIT file(s) to François Teyssier francois.teyssier [at] dbmail.com to be added to this data repository.
Reduce your spectra with all your instrumental defect but do not correct from heliocentric velocity and do not remove telluric lines.
Use as much as possible BeSS FITS file format. Specially:
* BSS_SITE = your location
* BSS_INST = your instrument
* BSS_TELL = did you remove telluric lines
* BSS_VHEL = helioventric velocity correction on your spectrum.
* BSS_NORM = is your spectrum normalized (continuum corrected)?
* BSS_ITRP = your spectrograph typical resolving power
If possible, put exposure time in [s] seconds.
Fill-in SITELAT (Latitude) and SITELONG (Longitude) in your FITS header if possible.
Respect DATE-OBS format: yyyy-mm-dd hh:mm:ss...
For echelle or eShel spectra, please provide a merged spectrum in a single file (xxx.FIT) and all your individual orders in a compressed archive (xxx.ZIP).
Use if possible .FIT as FITS file extension.
Aras Forum dedicated to T tauri campaign
for exchanges between observers, questions, and so on
http://www.spectro-aras.com/forum/viewforum.php?f=28
RY Tau Light Curve (R and V bands) from AAVSO data base
Darryl Sergison (University of Exeter) has requested AAVSO assistance with a campaign he is organizing on six T Tauri stars
"In Autumn 2013 I [and my PhD supervisor Tim Naylor of Exeter University are] undertaking a new study into the nature of pre-main-sequence low mass stars, using time series optical spectroscopy and UV-Visual-IR photometry...to build a clearer picture of the environment around young solar-type stars and characterise their various disc, accretion, and outflow structures"
"This study offers a great opportunity for professional-amateur collaboration as the objects (with V magnitudes of 10 - 13) are well within the reach of photometry by small telescopes. Amateur observations are uniquely useful to us in the study of chaotically variable young stars as they offer crucial datapoints in the lightcurve between observations made by professional telescopes.
"We would be very keen to recruit(!) AAVSO observers who are interested in being part of this study and able to contribute visual or (V and Rc band) filtered CCD photometry. All contributing observers will be acknowledged in the published papers, significant contributors may also be co-authors. I do have one spare 1.25" V band filter that I could lend to any interested observer who may wish to borrow it for the duration of this programme. [If you are interested in borrowing it please email eowaagen@aavso.org]."In preparation for the main data collection next autumn, we would like to start monitoring targets immediately. The first 3 targets that we will be studying are RY Tau, DN Tau, and DR Tau [the other 3 targets will be announced later]...
As far as observations go, almost anything is useful. We are hoping to investigate periodicity for a range of phenomena on timescales of months to hours"Spectroscopy would be very welcome,
- particularly around H-alpha (6563Å) if the resolution is greater than a few thousand.
- Alternatively, low resolution right across the optical would be great , particularly if a nearby main sequence star of similar spectral type can be captured at a similar time and air-mass so that we can characterise the system and atmosphere response at the time of the observation."
Targets list :
RA [2000] Dec [2000] Magnitude
rangeCurrent Mag B - V RY Tau DN Tau DR Tau Reference stars list (for computation of atmospheric and instrumental response)
Target RY Tau DN Tau DR Tau
Links to pages / Log of observations and download files :
Links to pages Log of observations
and dowload spectra
Applications of different spectroscopic techniques for the YSO programme
Notice from Darryl Sergison :
List of ARAS Observers :
Christian Buil
Stéphane Charbonnel
Thierry Garrel
François Teyssier
Thierry Lemoult
Robin Leadbeater
Stéphane Charbonnel
Andrew Smith
Targets at medium resolution (R = 2400)
__________________________________________________________________________________________________________________________________________________________
References
AAVSO Alert notice # 473 : http://www.aavso.org/aavso-alert-notice-473
AAVSO Special notice # 306 : http://www.aavso.org/aavso-special-notice-306
Related sites
- Christian Buil's T Tauri Campaign Web Page : http://www.astrosurf.com/buil/campaign/ttauri/obs.htm
