SMSS J031300.36-670839.3

SMSS J031300.36-670839.3

NASA/STScI
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Hydrus
Right ascension 03h 13m 00.36s[1]
Declination −67° 08′ 39.3″[1]
Apparent magnitude (V) 14.7[1]
Astrometry
Distance6,000 ly
Details
Surface gravity (log g)2.3[1] cgs
Temperature5,125[1] K
Metallicity [Fe/H]≤−7.1 (<3D>,nLTE)[1] dex
Age13.6 Gyr
Characteristics
Evolutionary stage main sequence star
Spectral type K[2]
Other designations
SM0313,[3] SMSS J0313-6708,[4] SMSS 0313,[5] SMSS 0313-6708, SMSS J031300.36-670839.3

SMSS J031300.36-670839.3 (shortened as SMSS J0313-6708;[4] abbreviated to SM0313[3]) is a star in the Milky Way at the distance of 6000 light years from Earth. With an age of approximately 13.6 billion years,[6] it is one of the oldest stars known. Another star, HD 140283, is considered to be older, but there is uncertainty in values of its age. This makes SM0313 the oldest known star with an accurate determination of its age.[2][7][8] The star formed only about 100 million years after the Big Bang, and has been shining for 13.6 billion years. The star's very low upper limit of iron of less than one ten millionth the iron level of the Sun,[9] suggests that it is a first generation Population II star, formed from the gas cloud enriched by one of the very first stars.[7] SMSS J031300.36-670839.3 also has a much higher carbon supply compared to iron, more than a thousand times greater.[7] Apart from hydrogen, which appeared in the Big Bang, the star also contains carbon, magnesium, and calcium which could have been formed in a low energy supernova.[9] Methylidyne (CH) is also detected by its absorption line. No oxygen or nitrogen have been detected.[1] The star is a K class dwarf.[2]

The star was discovered by a team led by Australian National University astronomers.[8] The discovery was reported in Nature on 9 February 2014[1] and indicates that the supernovae of first generation stars may not have been as powerful as previously thought.[7]

The discovery was made possible by the SkyMapper,[8] a fully automated optical telescope at Siding Spring Observatory near Coonabarabran, New South Wales, Australia.[9] SkyMapper was built to replace the Great Melbourne Telescope at Mount Stromlo after that telescope was burnt in the 2003 Canberra bushfires.[10] Its purpose was to do whole sky surveys.

Elemental abundance compared to Sun[1]
Elements [M/H]
Lithium 0.7
Carbon −2.6
Magnesium −3.8
Calcium −7

See also

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Keller, S. C.; Bessell, M. S.; Frebel, A.; Casey, A. R.; Asplund, M.; Jacobson, H. R.; Lind, K.; Norris, J. E.; Yong, D.; Heger, A.; Magic, Z.; Da Costa, G. S.; Schmidt, B. P.; Tisserand, P. (9 February 2014). "A single low-energy, iron-poor supernova as the source of metals in the star SMSS J031300.36−670839.3". Nature (Nature). arXiv:1402.1517. Bibcode:2014Natur.506..463K. doi:10.1038/nature12990. Retrieved 10 February 2014.
  2. ↑ 2.0 2.1 2.2 Gary, Stuart (2014-02-12). "Oldest known star reveals early Universe". StarStuff. ABC Science. Retrieved 1 March 2014.
  3. ↑ 3.0 3.1 Kooser, Amanda (10 February 2014). "Astronomers track down oldest known star in the universe". CNET. CBS Interactive Inc. Retrieved 10 February 2014.
  4. ↑ 4.0 4.1 "Most metal-poor star hints at universe's first supernovae". ScienceDaily. 24 September 2014.
  5. ↑ "Australian astronomers find oldest known star in the universe". Astro Bob. 2014-02-10.
  6. ↑ Larissa Nicholson (9 February 2014). "New star found by ANU reserchers may lead to universal truth". The Sydney Morning Herald. Retrieved 9 February 2014.
  7. ↑ 7.0 7.1 7.2 7.3 "Researchers identify one of the earliest stars in the universe". Massachusetts Institute of Technology. 9 February 2014. Retrieved 9 February 2014.
  8. ↑ 8.0 8.1 8.2 Brainard, Curtis (10 February 2014). "The Archaeology of the Stars". New York Times. Retrieved 10 February 2014.
  9. ↑ 9.0 9.1 9.2 Keller, Stefan (10 February 2014). "The oldest star discovery tells much about the early universe". The Conversation Media Group. Retrieved 10 February 2014.
  10. ↑ Miller, Barbara (25 May 2009). "SkyMapper telescope to explore southern sky". ABC PM. Retrieved April 17, 2012.