Within the past two years, the number of M stars known to have stellar cycleshas grown from a handful to a few dozen, including several fully convectivestars which, it was generally believed, are not capable of supporting magneticcycles. And of the hundreds of stars with cycles, only seven have been monitoredin X rays (one of them a late M stars), but their results tentatively pointtoward a surprisingly simple relationship between X-ray cycle amplitude andRossby number (Ro). These observational discoveries have occurred at the sametime as significant advances in theoretical models, some of which predict thatfully convective stars CAN sustain cycles. We request observations of four starsthat span a wide range of Ro and spectral type and will expand the X-ray perspective.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2018-07-30T16:44:42Z/2019-04-18T21:56:28Z
Version
19.17_20220121_1250
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 Bradford Wargelin, 2020, 'Stellar Cycle Sampling\: the X-Ray Expansion', 19.17_20220121_1250, European Space Agency, https://doi.org/10.5270/esa-jcpt375
