HD 222925 information

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.
Observation data; Epoch J2000.00 Equinox J2000.00
Constellation	Tucana
Right ascension	23h 45m 17.607s
Declination	−61° 54′ 42.84″
Apparent magnitude (V)	9.03
Characteristics
Evolutionary stage	horizontal branch
Spectral type	F8 Sr Eu (ApSrEu)
Astrometry
Radial velocity (Rv)	−38.9±0.6 km/s
Proper motion (μ)	RA: 143.803 mas/yr ; Dec.: −99.109 mas/yr
Parallax (π)	2.2202 ± 0.0117 mas
Distance	1,469 ± 8 ly ; (450 ± 2 pc)
Details
Mass	0.75±0.20 M☉
Radius	6 R☉
Luminosity	43 L☉
Surface gravity (log g)	2.54±0.17 cgs
Temperature	5,636±103 K
Metallicity [Fe/H]	−1.47±0.08 dex
Other designations
	CD−62°1462, HD 222925, HIP 117168
Database references
SIMBAD	data

HD 222925 is a horizontal branch star about 1,470 light years away in the southern constellation Tucana. It is magnitude 9, far below naked-eye visibility. It is an 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]

^ ^a ^b ^c Cite error: The named reference roederer2022 was invoked but never defined (see the help page).
^ ^a ^b ^c ^d ^e Cite error: The named reference edr3 was invoked but never defined (see the help page).
^ Cite error: The named reference bailer2011 was invoked but never defined (see the help page).
^ ^a ^b Cite error: The named reference cunha2019 was invoked but never defined (see the help page).
^ Cite error: The named reference houk1975 was invoked but never defined (see the help page).
^ ^a ^b ^c Cite error: The named reference roederer2018 was invoked but never defined (see the help page).
^ Cite error: The named reference cruzalebes2019 was invoked but never defined (see the help page).
^ Cite error: The named reference umich was invoked but never defined (see the help page).
^ Cite error: The named reference sherbourne was invoked but never defined (see the help page).
^ Cite error: The named reference carnegie was invoked but never defined (see the help page).

[roederer2022-1] Cite error: The named reference roederer2022 was invoked but never defined (see the help page).

[edr3-2] Cite error: The named reference edr3 was invoked but never defined (see the help page).

[bailer2011-3] Cite error: The named reference bailer2011 was invoked but never defined (see the help page).

[cunha2019-4] Cite error: The named reference cunha2019 was invoked but never defined (see the help page).

[houk1975-5] Cite error: The named reference houk1975 was invoked but never defined (see the help page).

[roederer2018-6] Cite error: The named reference roederer2018 was invoked but never defined (see the help page).

[cruzalebes2019-7] Cite error: The named reference cruzalebes2019 was invoked but never defined (see the help page).

[umich-8] Cite error: The named reference umich was invoked but never defined (see the help page).

[sherbourne-9] Cite error: The named reference sherbourne was invoked but never defined (see the help page).

[carnegie-10] Cite error: The named reference carnegie was invoked but never defined (see the help page).

Observation data Epoch J2000.00 Equinox J2000.00
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]
Constellation	Tucana
Right ascension	23^h 45^m 17.607^s^[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]
Astrometry

Radial velocity (R_v)	−38.9±0.6^[6] km/s
Proper motion (μ)	RA: 143.803^[2] mas/yr Dec.: −99.109^[2] mas/yr
Parallax (π)	2.2202 ± 0.0117 mas^[2]
Distance	1,469 ± 8 ly (450 ± 2 pc)

Details

Mass	0.75±0.20^[6] `M`_☉
Radius	6^[7] `R`_☉
Luminosity	43^[4] `L`_☉
Surface gravity (log g)	2.54±0.17^[1] cgs
Temperature	5,636±103^[1] K
Metallicity [Fe/H]	−1.47±0.08^[6] dex

Other designations
CD−62°1462, HD 222925, HIP 117168
Database references
SIMBAD	data