| Proposal ID | 030101 |
| Title | X-ray spectroscopy of H1504+65, an extremely hot bare stellar core |
| Download Data Associated to the proposal | https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0301010101 |
| DOI | https://doi.org/10.5270/esa-1l21nv0 |
| Principal Investigator, PI | Prof Klaus Werner |
| Abstract | H1504+65 is the hottest known white dwarf (Teff=200,000 K). Its photosphere ismainly composed of carbon and oxygen, hence this unique white dwarf resemblesthe bare stellar core of a former red giant. Because of its high effectivetemperature H1504+65 is the only star at all which shows a photosphericabsorption line spectrum in the soft X-ray region. We have analysed a Chandraspectrum and identified a wealth of spectral lines from highly ionized O, Ne,and Mg. We also detect nickel lines but, surprisingly, fail to detect iron. Thereduced iron opacity allows thermal radiation to escape from deep hot layers.Our models predict that XMM-Newton could for the first time acquire a stellarphotospheric spectrum in the 10-30 Angstroem (1.2-0.4 KeV) region. This enables a precise temperature determination. |
| Publications |
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| Instrument | EMOS1, EMOS2, EPN, OM, RGS1, RGS2 |
| Temporal Coverage | 2005-09-25T07:32:05Z/2005-09-25T15:52:19Z |
| Version | 21.51_20241115_1113 |
| 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. |
| Creator Contact | https://www.cosmos.esa.int/web/xmm-newton/xmm-newton-helpdesk |
| Date Published | 2006-10-18T00:00:00Z |
| Last Update | 2026-07-09 |
| Keywords | "XMM-Newton", "white dwarf teff", "XMM", "effective temperature h1504", "nickel lines", "chandra spectrum", "bare stellar core", "mainly composed", "white dwarf resembles", "soft xray region", "xmm newton", "precise temperature", "models predict", "stellar photospheric spectrum", "former red giant", "kev region", "x ray spectroscopy", "spectral lines", "deep hot layers" |
| Publisher And Registrant | European Space Agency |
| Credit Guidelines | European Space Agency, Prof Klaus Werner, 2006, 'X-ray spectroscopy of H1504+65, an extremely hot bare stellar core', 21.51_20241115_1113, European Space Agency, https://doi.org/10.5270/esa-1l21nv0 |
| Rights | Data hosted in the ESA Space Science Archives are distributed under the CC BY-NC 3.0 IGO license. |