HIP 11952 is a

star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

in the

Milky Way The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye ...

galaxy, located 375 light-years away from the Sun. While the spectral lines strongly indicate that the star is of spectral type F2V-IV, previous analyses have stated that the star is a G8III giant star and an F0V main-sequence star. Located in the constellation Cetus, the star has a

metallicity In astronomy, metallicity is the abundance of elements present in an object that are heavier than hydrogen and helium. Most of the normal physical matter in the Universe is either hydrogen or helium, and astronomers use the word ''"metals"'' as a ...

only 1% that of the Sun. It is nearing the end of its lifetime on the

main sequence In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Her ...

, and will soon begin the transition into a

red giant A red giant is a luminous giant star of low or intermediate mass (roughly 0.3–8 solar masses ()) in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius large and the surface temperature around or ...

Claims of planet detection

In 2012 it was announced that HIP 11952 had two giant planets, this would have made it the oldest and most metal-poor planet host star known. This would have posed a challenge to planetary formation, as the chances of a planet forming so early in the Universe's history, with such a small amount of heavy elements with which to form planets, are believed to be remote. Further measurements of HIP 11952 were made on 35 nights over about 150 days, from August 7, 2012, to January 6, 2013, using the newly installed high resolution spectrograph

HARPS-N HARPS-N, the ''High Accuracy Radial velocity Planet Searcher for the Northern hemisphere'' is a high-precision radial-velocity spectrograph, installed at the Italian Telescopio Nazionale Galileo, a 3.58-metre telescope located at the Roque de los ...

at the 3.58m

Telescopio Nazionale Galileo The Galileo National Telescope, ( it, Telescopio Nazionale Galileo; TNG; code: Z19) is a 3.58-meter Italian telescope, located at the Roque de los Muchachos Observatory on the island of La Palma in the Canary Islands, Spain. The TNG is operated b ...

telescope on La Palma Island (Canary Islands) and

HARPS The High Accuracy Radial Velocity Planet Searcher (HARPS) is a high-precision echelle planet-finding spectrograph installed in 2002 on the ESO's 3.6m telescope at La Silla Observatory in Chile. The first light was achieved in February 2003. H ...

at the European Southern Observatory's 3.6m telescope on

La Silla La Silla may refer to: * La Silla Observatory, an astronomical observatory in Chile * Cerro de la Silla, a mountain and natural monument located within the metropolitan area of the city of Monterrey, Nuevo León, in northeastern Mexico. * La Sill ...

(Chile). Following their analysis, they were able to confidently exclude, through non-detection, the presence of the two giant planets with periods of 6.95 ± 0.01 days and 290.0 ± 16. 2 days. They also reasoned that the previously mistaken detections were probably due to instrument measurement errors. Re-analysis of the FEROS data revealed a problem with the barycentric correction used to derive the radial velocities; this error had led to the erroneous detection claim.

References

Notes

{{Stars of Cetus Cetus 011952 F-type main-sequence stars 016031 BD-13 0482

Claims of planet detection

See also

References

Notes