Stephen Groombridge FRS (7 January 1755,
GoudhurstGoudhurst is a village in Kent on the Weald, about south of Maidstone.It stands on a crossroads , where there is a large village pond. It is also in the Cranbrook School catchment area....
– 30 March 1832,
BlackheathBlackheath is a district of South London, England. It is named from the large open public grassland which separates it from Greenwich to the north and Lewisham to the west...
) was a British
astronomerAn astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
.
In 1806, using a then new
transit circleThe meridian circle, transit circle, or transit telescope is an instrument for observing the time of stars passing the meridian, at the same time measuring its angular distance from the zenith...
built by
Edward TroughtonEdward Troughton FRS was a British instrument maker who was notable for making telescopes and other astronomical instruments.Troughton was born at Corney, Cumberland...
, he began compiling a
star catalogueA star catalogue, or star catalog, is an astronomical catalogue that lists stars. In astronomy, many stars are referred to simply by catalogue numbers. There are a great many different star catalogues which have been produced for different purposes over the years, and this article covers only some...
of stars down to about eighth or ninth magnitude. He spent ten years making observations on the
Groombridge Transit CircleGroombridge Transit Circle was a meridian transit circle made by Edward Troughton for Stephen Groombridge in 1806, which Groombridge used to compile data for the star catalogue, Catalogue of Circumpolar Stars. The advantage of a transit circle over a mural circle is that it allows measuring right...
and another ten years doing reductions of the data (correcting for
refractionRefraction is the change in direction of a wave due to a change in its speed. It is essentially a surface phenomenon . The phenomenon is mainly in governance to the law of conservation of energy. The proper explanation would be that due to change of medium, the phase velocity of the wave is changed...
, instrument error and clock error). In 1827 he suffered a "severe attack of paralysis" from which he never fully recovered. Others continued the work, continuing with corrections for
aberrationThe aberration of light is an astronomical phenomenon which produces an apparent motion of celestial objects about their real locations...
and
nutationNutation is a rocking, swaying, or nodding motion in the axis of rotation of a largely axially symmetric object, such as a gyroscope, planet, or bullet in flight, or as an intended behavior of a mechanism...
among others, and his
Catalogue of Circumpolar Stars was published posthumously in 1838 with the help of fellow astronomer
George Biddell AirySir George Biddell Airy PRS KCB was an English mathematician and astronomer, Astronomer Royal from 1835 to 1881...
(1801-1892) and others. An earlier edition had been published in 1833 but was found to contain errors and was withdrawn.
A few years later in 1842, one of the stars in his catalogue,
Groombridge 1830Groombridge 1830 is a star in the constellation Ursa Major.-Description:It is a yellowish class G8 subdwarf catalogued by Stephen Groombridge with the Groombridge Transit Circle between 1806 and the 1830s and published posthumously in his star catalog, Catalogue of Circumpolar Stars...
, was discovered by
Friedrich Wilhelm ArgelanderFriedrich Wilhelm August Argelander was a German astronomer. He is known for his determinations of stellar brightnesses, positions, and distances.- Life and work :...
to have a very high
proper motionThe proper motion of a star is its angular change in position over time as seen from the center of mass of the solar system. It is measured in seconds of arc per year, arcsec/yr, where 3600 arcseconds equal one degree. This contrasts with radial velocity, which is the time rate of change in...
. For many decades its proper motion was the highest known; today it still occupies third place.
Selected writings
- edited by George Biddell Airy; has biographical information for Groombridge
See also
- 5657 Groombridge, an asteroid named in his honour
- Groombridge 1618
Groombridge 1618 is a star in the constellation Ursa Major. It is located close to Earth, at a distance of less than 16 light years. This is an orange dwarf star of spectral type K5 V.-Properties:...
, a nearby star
- Groombridge 34
Groombridge 34 is a binary star system located about 11.7 light years from our own Sun. It consists of two red dwarf stars in a nearly circular orbit with a separation of about 147 astronomical units. Both stars in this pair exhibit variability due to random flares and they have been given variable...
, a double star. The 16th nearest star system
Further reading
- * Adapted from Sky & Telescope, May, 1974, page 296
External links