| Name | 072121 |
| Title | What is Nunki? |
| URL | https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0721210101 |
| DOI | https://doi.org/10.5270/esa-bh1n101 |
| Author | Dr Lidia Oskinova |
| Description | The X-ray emission of near-main sequence B stars is poorly understood, and the mechanism that generates it is not yet fully identified. It is known that, in general, the main-sequence B-type stars are relatively weak X-ray sources, with X-ray luminosities being only 10^{-9} as a fraction of their bolometric luminosities. The XMM-Newton slew survey revealed that the B2.5V star sigma Sgr (Nunki) is at least 100 times more X-ray luminous compared to an average star of this spectral type. We propose a short 5 ks observation to verify the position and the flux of the X-ray source coinciding with sigma Sgr. If a high X-ray flux is confirmed, it will have important consequences for our understanding of fast rotating and magnetic B-type stars. |
| Publication | No observations found associated with the current proposal |
| Instrument | EMOS1, EMOS2, EPN, OM, RGS1, RGS2 |
| Temporal Coverage | 2013-09-22T06:00:13Z/2013-09-22T08:46:53Z |
| Version | 17.56_20190403_1200 |
| 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. |
| Creator Contact | https://www.cosmos.esa.int/web/xmm-newton/xmm-newton-helpdesk |
| Date Published | 2014-10-10T00:00:00Z |
| Publisher And Registrant | European Space Agency |
| Credit Guidelines | European Space Agency, Dr Lidia Oskinova, 2014, 072121, 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-bh1n101 |