Messier 35 or M35, also known as NGC 2168 or the Shoe-Buckle Cluster, is a relatively close

open cluster An open cluster is a type of star cluster made of tens to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way galaxy, and ...

star A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sk ...

s in the west of Gemini, at about the declination of the Sun when the latter is at

June solstice The June solstice is the solstice on Earth that occurs annually between 20 and 22 June according to the Gregorian calendar. In the Northern Hemisphere, the June solstice is the summer solstice (the day with the longest period of daylight), while ...

. It was discovered by

Philippe Loys de Chéseaux Jean-Philippe Loys de Cheseaux (; 4 May 1718 – 30 November 1751) was a Swiss astronomer. Biography Loys de Cheseaux was born on 4 May 1718 in Lausanne, Vaud, to Paul-Etienne Loys de Cheseaux, a banneret, and Estienne-Judith de Crousaz. His ...

around 1745 and independently discovered by

John Bevis John Bevis (10 November 1695 – 6 November 1771) was an English medical doctor, electrical researcher and astronomer. He is best known for discovering the Crab Nebula in 1731. He was educated at Christ Church, Oxford, being awarded his ...

before 1750. It is scattered over part of the sky almost the size of the full moon and is away. The compact open cluster NGC 2158 lies directly southwest of it. Leonard & Merritt (1989) computed the mass of M35 using a

statistical technique A statistical hypothesis test is a method of statistical inference used to decide whether the data provide sufficient evidence to reject a particular hypothesis. A statistical hypothesis test typically involves a calculation of a test statistic. T ...

based on

proper motion Proper motion is the astrometric measure of changes in the apparent places of stars or other celestial objects as they move relative to the center of mass of the Solar System. It is measured relative to the distant stars or a stable referenc ...

velocities of its stars. The mass within the central was found to be between 1600 and 3200 solar masses, consistent with the mass of a realistic stellar population within the same radius. Bouy et al. in 2015 found a mass of around within the central . There are 305 stars that can be intrinsically shown to be extremely likely to be members, and up to 4,349 averaging the 50% membership probability, from the kinematic (such as

parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different sightline, lines of sight and is measured by the angle or half-angle of inclination between those two lines. Due to perspective (graphica ...

and

) and spectral data published before 2015. The cluster's

metallicity In astronomy, metallicity is the Abundance of the chemical elements, abundance of Chemical element, elements present in an object that are heavier than hydrogen and helium. Most of the normal currently detectable (i.e. non-Dark matter, dark) matt ...

is e/H= , where −1 would be ten times less metallic than the sun. Of 418 probable members, Leiner et al. in 2015 found 64 that have variable radial velocities thus are

binary star A binary star or binary star system is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved as separate stars us ...

systems. Four probable members are chemically peculiars, while HD 41995, which in the (telescopic angular) cluster field, shows

emission line A spectral line is a weaker or stronger region in an otherwise uniform and continuous spectrum. It may result from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used ...

s. Hu et al. in 2005 found 13

variable star A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes systematically with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are ...

s in the field; at least three are suspect as cluster members. To be a member means to have a gravitational tie or, if recently freed, having been created by the same event.

References and footnotes

External links

Messier 35, SEDS Messier pages

M35 – Nightskyinfo.com
* * - featured M35 * {{DEFAULTSORT:Messier 35 Messier 035 Messier 035 035 Messier 035 Orion–Cygnus Arm ?

See also

References and footnotes

External links