Hercules X-1 | has eclipse duration 0.24 days (in X-rays) | ![2001-09-27 09:30:33.0 2001-09-27 09:30:33.0](facet.gif) |
is a part of Hercules | ![2001-09-27 09:30:33.0 2001-09-27 09:30:33.0](facet.gif) |
has eccentricity e < 0.1 | ![2001-09-27 09:30:33.0 2001-09-27 09:30:33.0](facet.gif) |
has distance 5 kpc | ![has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:30:33.0 has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:30:33.0](facet.gif) |
has synonym 3U 1653+35 | ![2001-09-27 09:30:33.0 2001-09-27 09:30:33.0](facet.gif) |
has orbital period 1.7 days | ![has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:30:33.0 has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:30:33.0](facet.gif) |
has definition An X-ray pulsar, a member of an occulting binary system. The visible component has been identified as the blue variable HZ Herculis, whose spectrum varies from late A or early F to B. Her X- l has a pulsation period of 1.2378 seconds, presumably its rotation period, and exhibits a 35-day quasi-periodicity in the X-ray region (but not in the optical). It is probably a rotating neutron star in a circular orbit with a mass of about 0.7 Msun, which is accreting matter from HZ Her. The orbital period is stable, but the pulsation period is speeding up at a rate of about 1 part in 105 per year. The X-ray eclipse lasts 0.24 days. | ![has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:30:33.0 has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:30:33.0](facet.gif) |
is an instance of X-ray pulsar | ![2001-09-27 09:30:33.0 2001-09-27 09:30:33.0](facet.gif) |
is an instance of eclipsing binary | ![2001-09-27 09:30:33.0 2001-09-27 09:30:33.0](facet.gif) |
periodic variable | has period | ![2001-09-27 09:30:34.0 2001-09-27 09:30:34.0](facet.gif) |
pulsar | has acronym PSR | ![2001-09-27 09:30:32.0 2001-09-27 09:30:32.0](facet.gif) |
binary star | has number of stars 2 | ![2001-09-27 09:30:54.0 2001-09-27 09:30:54.0](facet.gif) |
variable | has name designated with - R, S, T, U, V, W, X, Y, or Z and the genitive of the latin constellation name
- RR, RS, RT, RU, RV, RW, RX, RY, or RZ and the genitive of the latin constellation name when the single letter designations are exhausted
- AA...AZ, BB...BZ, etc. (omitting J), which ends with QQ...QZ and the genitive of the latin constellation namewhen the RR...RZ designations are exhausted
- V 335, V 336, etc., when the double letter designations are exhausted
| ![2001-09-27 09:30:34.0 2001-09-27 09:30:34.0](facet.gif) |
has observational problem some difficulty in distinguishing between various kinds | ![2001-09-27 09:30:34.0 2001-09-27 09:30:34.0](facet.gif) |
has observable variation time scale within a period of decades | ![has URL: http://www.aavso.org, 2001-09-27 09:30:34.0 has URL: http://www.aavso.org, 2001-09-27 09:30:34.0](facet.gif) |
has light curve | ![2001-09-27 09:30:34.0 2001-09-27 09:30:34.0](facet.gif) |
has optical brightness variation 0.2 magnitudes or greater | ![2001-09-27 09:30:34.0 2001-09-27 09:30:34.0](facet.gif) |
has amplitude | ![2001-09-27 09:30:34.0 2001-09-27 09:30:34.0](facet.gif) |
star system | has abundance half the stars in the solar neighborhood are members of star systems | ![2001-09-27 09:30:54.0 2001-09-27 09:30:54.0](facet.gif) |
star | has star surface temperature | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has spectral type | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has V magnitude | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has B magnitude | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has U magnitude | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has position on celestial sphere from the point of view of Earth | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has parallax from the point of view of Earth's orbit | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has proper motion | ![2001-09-27 09:30:24.0 2001-09-27 09:30:24.0](facet.gif) |
has radiation at surface which is diffused out from the hotter core | ![2001-09-27 09:30:24.0 2001-09-27 09:30:24.0](facet.gif) |
has energy source gravitational contraction and or fusion | ![2001-09-27 09:30:24.0 2001-09-27 09:30:24.0](facet.gif) |
has energy production which takes place primarily within the core | ![2001-09-27 09:30:24.0 2001-09-27 09:30:24.0](facet.gif) |
has surface density which depends on luminosity class | ![2001-09-27 09:30:24.0 2001-09-27 09:30:24.0](facet.gif) |
has surface temperature greater than 1000 Kelvin | ![2001-09-27 09:30:24.0 2001-09-27 09:30:24.0](facet.gif) |
has apparent magnitude | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has absolute magnitude | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has age | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has catalog star catalog | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has material hydrogen, helium | ![2001-09-27 09:30:24.0 2001-09-27 09:30:24.0](facet.gif) |
has velocity determined from proper motion and radial velocity | ![2001-09-27 09:30:25.0 2001-09-27 09:30:25.0](facet.gif) |
has mass greater than 0.08 the sun's mass | ![2001-09-27 09:30:24.0 2001-09-27 09:30:24.0](facet.gif) |
massive compact halo object | is a part of halo | ![2001-09-27 09:28:17.0 2001-09-27 09:28:17.0](facet.gif) |
celestial body | has spectra | ![2001-09-27 09:30:09.0 2001-09-27 09:30:09.0](facet.gif) |
dark matter | is a part of dark halo | ![2001-09-27 09:32:18.0 2001-09-27 09:32:18.0](facet.gif) |
hypothetical particle | has acceptance status hypothetical | ![2001-09-27 09:28:16.0 2001-09-27 09:28:16.0](facet.gif) |
physical object | has location or center of gravity | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has angular momentum | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has momentum | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has temperature | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has volume | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has extent | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
particle | obeys uncertainty principle | ![2001-09-27 09:28:02.0 2001-09-27 09:28:02.0](facet.gif) |
has frequency inversely proportional to the wavelength | ![2001-09-27 09:28:02.0 2001-09-27 09:28:02.0](facet.gif) |
has wavelength inversely proportional to its momentum | ![2001-09-27 09:28:02.0 2001-09-27 09:28:02.0](facet.gif) |
has charge | ![2001-09-27 09:28:01.0 2001-09-27 09:28:01.0](facet.gif) |