Activity cycles are commonly found among late type stars through thechromospheric Ca II emission. Their coronal counterpart, remains elusive in mostcases, despite of the clear cycle observed in the solar corona, spanning as muchas 1.7 dex in Lx. The recent discovery of a Ca II cycle in HR 810 of just 1.6yr, the shortest to date, offers a unique opportunity to test the existence ofan X-ray counterpart of the cycle within two XMM-Newton observing periods. Thestar offers two more interesting properties: it represents a young (500 Myr)solar analog, and a 1.9 Mj planet orbits the star at 0.9 a.u. We started oursearch for the cycle of HR 810 in AO 10 and we intend to make 5 new snapshotsduring XMM-Newton AO 11, for a total of 25 ks, to complete the coverage of the cycle.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2012-05-19T12:14:26Z/2012-12-20T18:16:20Z
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 Jorge Sanz-Forcada, 2014, 'X-ray counterpart of the shortest activity cycle found to date', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-qnjuugq
