|Title||tau Boo.s magnetic polarity switch in X-rays - continued monitoring|
|Author||Mrs Katja Poppenhaeger|
|Description||tau Boo is the first star other than the Sun which has been observed to have a global magnetic field with switching polarity. In contrast to the Sun, tau Boo.s magnetic cycle has a duration of only two years. In the previous AO, we were awarded four EPIC pointings of 8 ks each to monitor tau Boo.s activity in X-rays, backing up our observations with optical measurements of the chromospheric activity as well as Zeeman Doppler Imaging. We propose to continue monitoring the star during this AO with XMM-Newton for a total of 32 ks as well as with Chandra for a total of 10 ks to gain more insight into the stellar activity cycle by comparing X-ray luminosities and coronal temperatures derived from the CCD spectra to the chromospheric activity profile and the magnetic field configuration of tau Boo.|
|Publication||A magnetic cycle of tau Bootis? The coronal and chromospheric view . Poppenhaeger, K., Gunther, H. M., . AN . 333-26 . 2012 . 2012AN....333...26P ,
XMM-Newton publication statistics . Ness, J.-U., Parmar, A. N., et all. . AN . 335-210 . 2014 . 2014AN....335..210N ,
Ensemble X-ray variability of active galactic nuclei. II. Excess variance and updated structure function . Vagnetti, F., Middei, R., et all. . A&A . 593-55 . 2016 . 2016A&A...593A..55V ,
The Million Optical - Radio-X-ray Associations (MORX) Catalogue . Flesch, Eric W., . PASA . 33-52 . 2016 . 2016PASA...33...52F ,
Four-month chromospheric and coronal activity cycle in tau Bootis . Mittag, M., Robrade, J., et all. . A&A . 600-119 . 2017 . 2017A&A...600A.119M ,
Discovery of a 23.8 h QPO in the Swift light curve of XMMU J134736.6+173403 . Carpano, S., Jin, C., . MNRAS . 477-3178 . 2018 . 2018MNRAS.477.3178C ,
|Instrument||EMOS1, EMOS2, EPN, OM, RGS1, RGS2|
|Mission Description||The European Space Agency's (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESA's 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 Earth's 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.
|Publisher And Registrant||European Space Agency|
|Credit Guidelines||European Space Agency, 2013-02-15T00:00:00Z, 067115, 17.56_20190403_1200. https://doi.org/10.5270/esa-3vn34kl|