This article needs to be updated. Please help update this article to reflect recent events or newly available information.(November 2010)
An astro-comb is a type of
frequency comb used in observational
astronomy to increase the accuracy of wavelength calibration in
spectrographs.[1][2] The increased accuracy reduces systematic errors and enhances detection of small variations in stellar
radial velocities caused by smaller orbiting
exoplanets (e.g. Earth-mass planets), among other applications.[3][4] Astro-combs are distinguished from conventional frequency combs by their focus on high
repetition frequencies (with mode spacings of ≥10 GHz).[5]
A green astro-comb was installed in January 2013 in the high accuracy radial velocity planet searcher in the northern hemisphere (
HARPS-N)
spectrograph at the
Telescopio Nazionale Galileo on the
Canary Islands.[6] The device was developed by a team led by Chih-Hao Li of
Harvard University. This astro-comb uses a
pulsed laser to filter starlight before feeding the signal into a spectrograph. As of December 2016, it is gathering data from Venus to demonstrate its ability to discover exoplanets.[7]
^Chae, Eunmi; Kambe, Eiji; Motohara, Kentaro; Izumiura, Hideyuki; Doi, Mamoru; Yoshioka, Kosuke (1 July 2021). "Compact green Ti:sapphire astro-comb with a 43 GHz repetition frequency". Journal of the Optical Society of America B. 38 (7): A1.
arXiv:2101.05926.
Bibcode:
2021JOSAB..38A...1C.
doi:
10.1364/JOSAB.419078.
S2CID231627499.
Pulses to Find Planets, (Archive of
Pulses to Find Planets Astro Biology Magazine, May 11, 2008. Accessed May 15, 2008. Based on a National Institute of Standards and Technology news release.)