Scholz's star
| Observation data Epoch J2000.0 [1] Equinox J2000.0 [1] | |
|---|---|
| Constellation | Monoceros |
| Right ascension | 07h 20m 03.254s [1] |
| Declination | −08° 46′ 49.90″ [1] |
| Apparent magnitude (V) | 18.3[2] |
| Characteristics | |
| Spectral type | M9 ± 1[2] T5[2] |
| Astrometry | |
| Radial velocity (Rv) | 83.1 [2] km/s |
| Proper motion (μ) | RA: -40.3 ± 0.2[3][2] mas/yr Dec.: -114.8 ± 0.4[3][2] mas/yr |
| Parallax (π) | 166 ± 28[3][2] mas |
| Distance | approx. 20 ly (approx. 6 pc) |
| Absolute magnitude (MV) | 19.4[4] |
| Details | |
| Mass | 0.15[2] M☉ |
| Age | 3–10 billion[2] years |
| Other designations | |
| Database references | |
| SIMBAD | data |
Scholz's Star (WISE designation WISE 0720−0846 or fully WISE J072003.20−084651.2) is a dim binary stellar system about 17–23 light-years (5.1–7.2 parsecs) from the Sun in the southern constellation Monoceros near the galactic plane.[2] It was discovered in 2013 by astronomer Ralf-Dieter Scholz. It passed through the Solar System's Oort cloud roughly 70,000 years ago.
Characteristics
The primary is a red dwarf with a stellar classification of M9±1 and has 86±2 Jupiter masses.[2] The secondary is probably a T5 brown dwarf with 65±12 Jupiter masses.[2] The system has 0.15 solar masses.[2] The pair orbit at a distance of about 0.8 astronomical units (120,000,000 kilometers; 74,000,000 miles)[2] with a period of roughly 4 years.[6] The system has an apparent magnitude of 18.3,[2] and is estimated to be between 3 and 10 billion years old.[2] With a parallax of 166 mas (0.166 arcseconds), there are about 80 known star systems closer to the Sun.[7] It is a late discovery, as far as nearby stars go, because past efforts concentrated on high-proper-motion objects.
Solar System flyby
Estimates indicate that the WISE 0720−0846 system passed about 52,000 astronomical units (0.25 parsecs; 0.82 light-years) from the Sun about 70,000 years ago.[2][5] 98% of mathematical simulations of the star system's trajectory indicated it passed through the Solar System's Oort cloud, or within 120,000 AU (0.58 pc; 1.9 ly) of the Sun.[2] Comets perturbed from the Oort cloud would require roughly 2 million years to get to the inner Solar System.[2] At closest approach the system would have had an apparent magnitude of about 11.4.[4] A star is expected to pass through the Oort Cloud every 100,000 years or so.[4] An approach as close or closer than 52,000 AU is expected to occur about every 9 million years.[2]
Naming
The star was first discovered to have been near the Solar System by astronomer Ralf-Dieter Scholz,[5] announced on arXiv in November 2013, and has been nicknamed Scholz's star.
See also
References
- 1 2 3 4 5 6 "2MASS J07200325-0846499 -- Brown Dwarf Candidate". SIMBAD. Retrieved 2015-02-18.
- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Mamajek, Eric E.; Barenfeld, Scott A.; Ivanov, Valentin D. (2015). "The Closest Known Flyby of a Star to the Solar System". The Astrophysical Journal. 800 (1). arXiv:1502.04655
. Bibcode:2015ApJ...800L..17M. doi:10.1088/2041-8205/800/1/L17. - 1 2 3 Burgasser, Adam J.; et al. (2015). "WISE J072003.20-084651.2: an Old and Active M9.5 + T5 Spectral Binary 6 pc from the Sun". The Astronomical Journal. 149 (3). 104. arXiv:1410.4288. Bibcode:2015AJ....149..104B. doi:10.1088/0004-6256/149/3/104.
- 1 2 3 Mamajek, Eric. "FAQ". Retrieved 2015-02-18.
- 1 2 3 "Featured Research: Closest known flyby of star to our solar system: Dim star passed through Oort Cloud 70,000 years ago". Science Daily. 17 February 2015. Retrieved 2015-02-21.
- ↑ Burgasser, Adam J.; et al. (2015). "Radio Emission and Orbital Motion from the Close-encounter Star–Brown Dwarf Binary WISE J072003.20–084651.2". The Astronomical Journal. 150 (6). 180. arXiv:1508.06332. Bibcode:2015AJ....150..180B. doi:10.1088/0004-6256/150/6/180.
- ↑ "THE ONE HUNDRED NEAREST STAR SYSTEMS". RECONS (Research Consortium On Nearby Stars). Retrieved 2015-02-18.