Messier 34
Encyclopedia
Messier 34 is an open cluster
in the constellation
Perseus
. It was probably discovered by Giovanni Batista Hodierna before 1654 and included by Charles Messier
in his catalog of comet
-like objects in 1764. Messier described it as, "A cluster of small stars a little below the parallel of γ (Andromedae). In an ordinary telescope of 3 feet one can distinguish the stars."
Based on the distance modulus
of 8.38, this cluster is located at a distance of about 470 parsecs, or 1,500 light years. For stars in the range from 0.12 to 1.0 solar mass
es, M34 contains an estimated 400 members. It spans about 35' on the sky which translates to a true radius of 7 light years. The cluster is just visible to the naked eye in very dark conditions, well away from city lights. It is well seen in binoculars
.
The age of this cluster lies between the respective ages of the Pleiades
open cluster at 100 million years and the Hyades
open cluster at 800 million years. Comparisons between the observed stellar spectra and the values predicted by stellar evolutionary models gives an age estimate of 200–250 million years for M34. This is roughly the age at which stars with 0.5 solar mass
es enter the main sequence
. By comparison, stars like the Sun enter the main sequence after 30 million years.
The average proportion of elements with higher atomic numbers than helium is termed the metallicity
by astronomers. This is expressed by the logarithm of the ratio of iron to hydrogen, compared to the same proportion in the Sun. For M34, the metallicity has a value of [Fe/H] = +0.07 ± 0.04. This is equivalent to a 17% higher proportion of iron compared to the Sun. Other elements show a similar abundance, with the exception of nickel which is underabundant.
At least 19 members of this cluster are white dwarf
s. These are stellar remnants of progenitor stars of up to eight solar mass
es that have evolved through the main sequence
and are no longer engaged in thermonuclear fusion to generate energy. 17 of the white dwarfs are of spectral type DA or DAZ, while one is a type DB and the last is a type DC.
Open cluster
An open cluster is a group of up 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 many more are thought to exist...
in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
Perseus
Perseus (constellation)
Perseus is a constellation in the northern sky, named after the Greek hero Perseus. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations defined by the International Astronomical Union...
. It was probably discovered by Giovanni Batista Hodierna before 1654 and included by Charles Messier
Charles Messier
Charles Messier was a French astronomer most notable for publishing an astronomical catalogue consisting of deep sky objects such as nebulae and star clusters that came to be known as the 110 "Messier objects"...
in his catalog of comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
-like objects in 1764. Messier described it as, "A cluster of small stars a little below the parallel of γ (Andromedae). In an ordinary telescope of 3 feet one can distinguish the stars."
Based on the distance modulus
Distance modulus
-Definition:The distance modulus \mu=m-M is the difference between the apparent magnitude m and the absolute magnitude M of an astronomical object...
of 8.38, this cluster is located at a distance of about 470 parsecs, or 1,500 light years. For stars in the range from 0.12 to 1.0 solar mass
Solar mass
The solar mass , , is a standard unit of mass in astronomy, used to indicate the masses of other stars and galaxies...
es, M34 contains an estimated 400 members. It spans about 35' on the sky which translates to a true radius of 7 light years. The cluster is just visible to the naked eye in very dark conditions, well away from city lights. It is well seen in binoculars
Binoculars
Binoculars, field glasses or binocular telescopes are a pair of identical or mirror-symmetrical telescopes mounted side-by-side and aligned to point accurately in the same direction, allowing the viewer to use both eyes when viewing distant objects...
.
The age of this cluster lies between the respective ages of the Pleiades
Pleiades (star cluster)
In astronomy, the Pleiades, or Seven Sisters , is an open star cluster containing middle-aged hot B-type stars located in the constellation of Taurus. It is among the nearest star clusters to Earth and is the cluster most obvious to the naked eye in the night sky...
open cluster at 100 million years and the Hyades
Hyades (star cluster)
The Hyades is the nearest open cluster to the Solar System and one of the best-studied of all star clusters. The Hipparcos satellite, the Hubble Space Telescope, and infrared color-magnitude diagram fitting have been used to establish a distance to the cluster's center of ~153 ly...
open cluster at 800 million years. Comparisons between the observed stellar spectra and the values predicted by stellar evolutionary models gives an age estimate of 200–250 million years for M34. This is roughly the age at which stars with 0.5 solar mass
Solar mass
The solar mass , , is a standard unit of mass in astronomy, used to indicate the masses of other stars and galaxies...
es enter the main sequence
Main sequence
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 Hertzsprung and Henry Norris Russell...
. By comparison, stars like the Sun enter the main sequence after 30 million years.
The average proportion of elements with higher atomic numbers than helium is termed the metallicity
Metallicity
In astronomy and physical cosmology, the metallicity of an object is the proportion of its matter made up of chemical elements other than hydrogen and helium...
by astronomers. This is expressed by the logarithm of the ratio of iron to hydrogen, compared to the same proportion in the Sun. For M34, the metallicity has a value of [Fe/H] = +0.07 ± 0.04. This is equivalent to a 17% higher proportion of iron compared to the Sun. Other elements show a similar abundance, with the exception of nickel which is underabundant.
At least 19 members of this cluster are white dwarf
White dwarf
A white dwarf, also called a degenerate dwarf, is a small star composed mostly of electron-degenerate matter. They are very dense; a white dwarf's mass is comparable to that of the Sun and its volume is comparable to that of the Earth. Its faint luminosity comes from the emission of stored...
s. These are stellar remnants of progenitor stars of up to eight solar mass
Solar mass
The solar mass , , is a standard unit of mass in astronomy, used to indicate the masses of other stars and galaxies...
es that have evolved through the main sequence
Main sequence
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 Hertzsprung and Henry Norris Russell...
and are no longer engaged in thermonuclear fusion to generate energy. 17 of the white dwarfs are of spectral type DA or DAZ, while one is a type DB and the last is a type DC.
External links
- Messier 34, SEDS Messier pages
- Messier 34 Amateur Image by Waid Observatory