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The Program to Link the HIPPARCOS Reference Frame to an Extragalactic Reference System Using the Fine Guidance Sensors of the Hubble Space Telescope Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1997AJ....114.2796H&db_key=AST
| An unbiased survey of field star X-ray emission To determine the X-ray luminosity function of normal stars, 1700 starsbrighter than 10th magnitude were surveyed by the imaging proportionalcounter aboard the Einstein Observatory. Seventy star positions werefound to contain excess X-ray counting rates. The number of stars persquare degree in a number of magnitude intervals was calculated as afunction of spectral type and luminosity class, and the total number ofstars for each spectral type brighter than magnitude 9.5 derived in thismanner was compared with the 1700-star sample. The agreement is good, asis that between the surface density of soft X-ray sources and the numberof stellar emitters predicted from the field star survey. It isconcluded that stars probably do not contribute significantly to thediffuse soft X-ray background. The findings are consistent with thenotion that stellar age and/or rotation velocity are importantdeterminants of stellar X-ray emission level.
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Datos observacionales y astrométricos
Constelación: | Boyero |
Ascensión Recta: | 14h44m28.79s |
Declinación: | +09°57'35.4" |
Magnitud Aparente: | 8.875 |
Movimiento Propio en Ascensión Recta: | -29.7 |
Movimiento Propio en Declinación: | -38.8 |
B-T magnitude: | 9.335 |
V-T magnitude: | 8.913 |
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