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Revision as of 22:26, 31 August 2011
| Observation data Epoch MJD 55411.0[1] Equinox J2000 | |
|---|---|
| Constellation | |
| Right ascension | 17:19:10.0730(1)[1] |
| Declination | −14:38:00.96(2)[1] |
| Characteristics | |
| Spectral type | millisecond pulsar[1] |
| Apparent magnitude (R) | >25.4[1] |
| Apparent magnitude (g) | >24.1[1] |
| Apparent magnitude (I) | >22.5[1] |
| Astrometry | |
| Distance | ~1,200[1] pc |
| Orbit[1] | |
| Primary | PSR J1719-1438 |
| Companion | PSR J1719-1438b |
| Period (P) | 0.090706293(2) days |
| Semi-major axis (a) | 0.001819(1) light seconds |
| Eccentricity (e) | <0.06 |
| Periastron epoch (T) | MJD 55411.0 |
| Details | |
| Other designations | |
| Database references | |
PSR J1719-1438 is a millisecond pulsar with a spin period of 5.7 ms located about 4000 ly from Earth in the direction of Serpens.[2][3] Millisecond pulsars are generally thought to begin as normal pulsars and then spin up by accreting matter from a binary companion.
Diamond planet
Timing measurements of PSR J1719-1438 show that it has a low-mass companion: PSR J1719-1438 b. The companion has a mass similar to that of Jupiter, but at about 40% of the diameter. It orbits the pulsar with a period of 2.17 hours at a distance of around 600,000 km (0.89 solar radii).[2] The companion is likely the remnants of a star whose outer layers were siphoned off by the more massive pulsar. Calculations show the companion has a minimum density of 23 grams per cubic centimeter and is probably a ultra-low mass carbon-oxygen white dwarf.[2]
Because the companion to PSR J1719-1438 is planet sized, made primarily of carbon (with an unknown amount of oxygen), and is very dense, it may be similar to a very large diamond. In the science press, the object has been called the "Diamond Planet"[3][4][5].
See also
- EF Eridani, a star system with a compact star and a degraded planetary-mass former star
References
- ^ a b c d e f g h i
. doi:10.1126/science.1208890.
{{cite journal}}: Cite journal requires|journal=(help); Missing or empty|title=(help) - ^ a b c Bailes, M. " Transformation of a Star into a Planet in a Millisecond Pulsar Binary". Science. doi:10.1126/science.1208890.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ a b "Star Transforms Into A Diamond Planet". Universe Today. Retrieved 8/26/2011.
{{cite web}}: Check date values in:|accessdate=(help) - ^ "Surprise! Alien Planet Made of Diamond Discovered". Space.com. Retrieved 8/25/2011.
{{cite web}}: Check date values in:|accessdate=(help) - ^ "A Planet made of Diamond". Max Planck Institut for Radio Astronomy. Retrieved 8/26/2011.
{{cite web}}: Check date values in:|accessdate=(help)