|Title||A First Look at a Short Period, Extremely Deep-Eclipsing Polar|
|Author||Prof Paolo Coppi|
|Description||We request exploratory follow-up of a new short period (95 min.), white dwarf binary, likely a polar with no accretion disk, that shows one of the deepest optical eclipses known (>5.7 mag). Such binaries are rare but valuable as the system.s inclination is strongly constrained; high time-resolution spectrophotometry, especially in and out of eclipse, allows "tomography" of the accretion flow and direct measurement of the radii of the white dwarf and its companion. This system shows no J band eclipse, i.e., it must have an unusually cool, low mass secondary, an M8+ dwarf. This combined with the short period suggests we may have a magnetic "period bouncer," a late binary evolutionary stage theoretically predicted to be common but difficult to detect in practice.|
|Publication||Serendipitous UV source catalogues for 10 years of XMM and 5 years of Swift . Yershov, V. N., . Ap&SS . 354-97 . 2014 . 2014Ap&SS.354...97Y ,
The Million Optical - Radio-X-ray Associations (MORX) Catalogue . Flesch, Eric W., . PASA . 33-52 . 2016 . 2016PASA...33...52F ,
The EXOD search for faint transients in XMM-Newton observations: Method and discovery of four extragalactic Type I X-ray bursters . Pastor-Marazuela, I., Webb, N. A., et all. . A&A . 640-124 . 2020 . 2020A&A...640A.124P ,
|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, 2012-09-29T00:00:00Z, 067342, 17.56_20190403_1200. https://doi.org/10.5270/esa-0fybdc6|