Zeta Reticuli
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| Observation data Epoch J2000.0 Equinox J2000.0 |
|
|---|---|
| Constellation | Reticulum |
| Zeta1 Reticuli | |
| Right ascension | 03h 17m 46.2s |
| Declination | -62° 34′ 31″ |
| Apparent magnitude (V) | 5.54 |
| Zeta2 Reticuli | |
| Right ascension | 03h 18m 12.8s |
| Declination | -62° 30′ 22.9″ |
| Apparent magnitude (V) | 5.24 |
| Characteristics | |
| Spectral type | G2.5 V / G1 V |
| U-B color index | 0.07 / 0.01 |
| B-V color index | 0.63 / 0.59 |
| Astrometry | |
| Radial velocity (Rv) | +12.2 km/s |
| Proper motion (μ) | RA: 1,337.73 / 1,331.01 mas/yr Dec.: 648.84 / 646.97 mas/yr |
| Parallax (π) | 82.51 / 82.79 ± 0.54 / 0.53 mas |
| Distance | 39.51 / 39.38 ly (12.12 / 12.08 pc) |
| Absolute magnitude (MV) | 5.12 / 4.83 |
| Details | |
| Zeta1 Reticuli | |
| Mass | 0.93 M☉ |
| Radius | 0.91 R☉ |
| Luminosity | 0.79 L☉ |
| Temperature | 5720 K |
| Metallicity | 60% Sun |
| Age | 8 × 109 years |
| Zeta2 Reticuli | |
| Mass | 0.99 M☉ |
| Radius | 0.99 R☉ |
| Luminosity | 1.02 L☉ |
| Temperature | 5840 K |
| Metallicity | 60% Sun |
| Age | 8 × 109 years |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Database references | |
| SIMBAD | data |
Zeta Reticuli (ζ Ret / ζ Reticuli) is a binary star system located about 39 light years away from Earth. It is located in the constellation Reticulum, and is visible to the unaided eye under very dark skies. Because of the southerly location of the system, it is not visible north of the tropics.
[edit] Characteristics
Originally thought to be old galactic halo Population II subdwarfs, the two stars are now thought to be younger galactic disk stars, but still considerably older than the Sun, perhaps as much as 8 billion years old. They belong to the Zeta Herculis Moving Group. Both stars share similar proper motions and distances confirming that they indeed form a wide binary star. The stars are approximately 9,000 AU apart. The stars revolve around each other once in over a million years. If the skies are dark enough for both stars to be visible, the stars are far enough apart to appear as a close pair of separate stars to the naked eye.
The stars, designated ζ1 Reticuli and ζ2 Reticuli, are both yellow dwarf (main sequence) stars remarkably similar to our Sun. The stars are only 60% as enriched with metals as the Sun. Small, terrestrial planets around less metal-rich stars are less likely according to our current knowledge.
ζ1 Reticuli is slightly less massive and luminous than the Sun. Spectral class of the star is G2.5 V.
ζ2 Reticuli has a very similar mass and luminosity to our Sun. The spectral type of the star is G1 V.
On September 20, 1996 a tentative discovery of a Hot Jupiter around ζ2 was reported, but the discovery was quickly retracted as the signal was shown to be caused by pulsations of the star.
[edit] See also
- Zeta Reticuli in fiction
- Role of Zeta reticuli in story of the abduction of Betty and Barney Hill
- Zeta reticulan, purported type of space alien
- ζ2 Reticuli is given as the star system for the location of fictional planetoid LV-426, also known as Acheron, the site of the crashed derelict ship in the 1979 film Alien. Acheron is described as a 1200 kilometer large asteroid, with a surface gravity of 0.86, orbiting a brown dwarf. The planet does not receive sufficient heat from the main star to be fit for colonization, but the trickle of radiation emitted by the brown dwarf qualifies the planet as "inhabitable".
[edit] External links
- "Zeta Reticuli". SolStation. http://www.solstation.com/stars2/zeta-ret.htm. Retrieved 2008-08-31.
- "Zeta(1) Reticuli". The Internet Stellar Database. http://www.stellar-database.com/Scripts/search_star.exe?ID=23900. Retrieved 2008-08-31.
- "Zeta(2) Reticuli". The Internet Stellar Database. http://www.stellar-database.com/Scripts/search_star.exe?ID=24100. Retrieved 2008-08-31.
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