Measuring stellar rotation periods (Prot) and coronal and chromospheric emissionin older open clusters is challenging, but essential to calibrate theage-activity-rotation relation that governs the evolution of low-mass andsolar-mass stars. We propose 60 ksec observations of three fields in the old(virgul600 Myr) Praesepe open cluster. These observations will double the overallnumber of X-ray-detected cluster members and of detected members with measuredProt. These detections will a) calibrate LX as an age estimator for field stars;b) establish the dependence of (unsaturated) LX on Rossby number for old, slowlyrotating stars; and c) combined with optical spectra, determine if chromosphericand coronal emission transition into the saturated regime at the same threshold.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2013-10-30T10:52:35Z/2013-10-31T06:49:15Z
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, Prof Marcel Agueros, 2014, 'What Can Old Stars Tell Us About The Lives They LedquestionMark A Survey of Praesepe', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-02l86n2
