71 Tau is an enigmatic object for two reasons: (i) it is the second brightestX-ray source in the Hyades, yet early-F stars as a rule are not strong coronalemitters; (ii) it lies 1 mag above the cluster main sequence, implying it is 150Myr older than other cluster members. Recent HST observations have discovered afaint stellar companion directly south of the primary that is seen only in itsUV emission lines. The high emission levels of this object are most readilyexplained if it is a tight binary of coronally active dG stars. We propose toobserve the O VII and O VIII lines near 20 A using the XMM RGS. The ratio ofthese line strengths will be used to determine whether the UV secondary canaccount for the striking X-ray properties of 71 Tau.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2010-08-17T01:16:50Z/2010-08-17T12:56:56Z
Version
17.56_20190403_1200
Mission Description
The European Space Agencys (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESAs second cornerstone of the Horizon 2000 Science Programme. It carries 3 high throughput X-ray telescopes with an unprecedented effective area, and an optical monitor, the first flown on a X-ray observatory. The large collecting area and ability to make long uninterrupted exposures provide highly sensitive observations. Since Earths atmosphere blocks out all X-rays, only a telescope in space can detect and study celestial X-ray sources. The XMM-Newton mission is helping scientists to solve a number of cosmic mysteries, ranging from the enigmatic black holes to the origins of the Universe itself. Observing time on XMM-Newton is being made available to the scientific community, applying for observational periods on a competitive basis.
European Space Agency, Dr Theodore Simon, 2011, 'X-Ray Spectroscopy of the Hyades Binary 71 Tau', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-0bno89k
