HD 222925

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HD 222925

Elements detected in HD 222925 totalling 65 with 42 coming from the r-process (31 ≤ Z ≤ 92) . Elements with no long-lived isotopes are indicated using the light gray font.[1]
Observation data
Epoch J2000.00      Equinox J2000.00
Constellation Tucana
Right ascension 23h 45m 17.607s[2]
Declination −61° 54′ 42.84″[2]
Apparent magnitude (V) 9.03[3]
Characteristics
Evolutionary stage horizontal branch
Spectral type F8 Sr Eu[4] (ApSrEu)[5]
Distance
1,469 ± 8 ly
(450 ± 2 pc)
Details
dex
HIP
 117168
Database references
SIMBADdata

HD 222925 is a

Ap star, a type of chemically peculiar star
with an over-abundance of certain metals in its spectrum.

HD 222925 has been referred to as the 'gold standard star' by the media.[8] In 2022, astronomers from the University of Michigan identified 65 elements in the star (including gold), a turning point to help the scientific community understand the rapid neutron capture process.[9] The elements were produced in a massive supernova or a merger of neutron stars early in the universe, and it was ejected into space where it later reformed into the current star.[10]

Gallery

  • Wavelength for each element detected by atomic number with each spectral line represented as a dot. A gap between ≈3145 Å and ≈3330 Å reflecting an atmospheric cutoff between STIS and MIKE spectra.[1]
    Wavelength for each element detected by atomic number with each spectral line represented as a dot. A gap between ≈3145 Å and ≈3330 Å reflecting an atmospheric cutoff between STIS and MIKE spectra.[1]
  • This mosaic shows two GHOST spectra of HD 222925.[11]
    This mosaic shows two
    GHOST spectra of HD 222925.[11]


References

  1. ^
    S2CID 248571656
    .
  2. ^
    doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR
    .
  3. S2CID 30425562
    .
  4. ^
    doi:10.1093/mnras/stz1332
    .
  5. Bibcode:1975mcts.book.....H
    .
  6. ^
    S2CID 119046070
    .
  7. S2CID 203610229
    .
  8. ^ "Astronomers find 'gold standard' star in Milky Way". University of Michigan News. 2022-05-10. Retrieved 2022-05-18.
  9. ^ Sherburne, Morgan; Michigan, University of. "Astronomers find 'gold standard' star in Milky Way". phys.org. Retrieved 2022-05-18.
  10. ^ Science, Carnegie (2022-05-13). "Astronomers find 'gold standard' star in Milky Way". Carnegie Institution for Science. Archived from the original on 2022-05-13. Retrieved 2022-05-18.
  11. ^ "Gemini's GHOST Captures Exquisite First Light Observations of a Bright, Chemically Rich Star". Retrieved 16 December 2022.

External links

Retrieved from "https://en.wikipedia.org/w/index.php?title=HD_222925&oldid=1187243709"