Request to monitor BP Tau in support of Chandra X-ray observations
Abstract:
Dr. Hans Moritz Guenther (Harvard-Smithsonian Center for Astrophysics) has requested nightly observations of the classical T Tauri star BP Tau in support of upcoming Chandra X-ray observations in his study of the accretion processes underway in this star.
Justification:
BP Tau is a classical T Tauri star in the Taurus-Aurigae star forming region. It is surrounded by a thick accretion disk. Material is falling from the accretion disk onto that star and we want to study this accretion shock and its interaction with the other layers of the star. The accretion shock is very hot (2-4 Mio Kelvin) and can be best seen in X-rays, but support from optical observers is needed. Specifically, we want to find out (1) if the X-ray spot is seen at the same time as bright or dark spots on the stellar surface, and (2) if the optical brightness changes, when the X-ray flux suddenly goes up or down due to changes of the rate of accretion or stellar flares. To do all this we need optical light curves over several weeks, so that we can see the rotational modulation and the average fluctuation in the light curve. For this we ask for the help of the AAVSO. "BP Tau was observed with the XMM-Newton satellite a few years ago and it is (after TW Hya) the second X-ray brightest classical T Tauri star in the sky. Now, we will observe BP Tau with Chandra for 9 days. This will be the longest X-ray exposure ever obtained for a young star. Unfortunately, the Chandra satellite is ageing and very restricted on where it can point on the sky, so the observation has to be split over several months.
Requested Data Types:
Photometry
Targets
| Name | Magnitude | Variability Type | Photometry Notes | Spectroscopy Notes |
|---|---|---|---|---|
| BP Tau | 11.50 | CTTS/ROT |
Cadence: Not Specified Precision: 100 |
Not Requested |
Spectroscopy Lines:
No spectroscopy lines provided
Photometry Filters:
No photometry filters provided
Comparison Stars:
No comparison stars provided
Co-Authorship
Observers are not eligible for co-authorship.
Additional Observer Input:
Not provided
Additional Submission Location:
Not provided
Forum URL
N/A
Notes:
Principal Investigator: Dr. Hans Moritz Guenther; Imported Campaign (Alert Notice #493)