Eagle Nebula

Database links to Eagle Nebula

Open star cluster data of the Eagle Nebula

Image of the Eagle Nebula, carried out at the European Southern Observatory
AladinLite
Constellation	Snake
Position equinox : J2000.0
Right ascension	18 ^h 18 ^m 54 ^s
declination	−13 ° 50 ′ 24 ″
Appearance
classification	II, 3, m, n (Trumpler), e (Shapley)
Brightness (visual)	6.0 likes
Brightness (B-band)	6.58 mag
Angular expansion	7.0 '
Brightest star	8.24 likes
Physical data
Redshift	60  ·  10 ⁻⁶
Radial velocity	18.0 km / s
distance	7000 ly (2100 pc )
diameter	15 years
Age	5.5 million years
history
Discovered by	Cheseaux
Discovery time	1745
Catalog names
M 16 • NGC 6611 • IC 4703 • C 1816-138 • OCl 54 • Mel 198 • Cr 375 • OCISM 10

The Eagle Nebula or IC 4703 (see index catalog ) is a nebula in connection with an open star cluster . The open star cluster bears the designation M 16 in the Messier catalog and the number NGC 6611 in the NGC . In many catalogs, nebulae and star clusters are listed as synonymous, so that the Messier catalog name is mostly used for the nebula as well. It is located in the constellation Snake at the coordinates 18h19m ( right ascension ) and −13 ° 47 '( declination ).

description

The Eagle Nebula is from the sun about 7,000 light-years away. It has an apparent brightness of 6.4 ^m .

The Eagle Nebula is an emission nebula ( type H II ) from which an open star cluster is formed. It consists mainly of hydrogen, which due to the low temperature could combine to form hydrogen molecules. The nebula, which is around 20 light years in size, contains pillars of dust that are up to 9.5 light years long and at the top of which there are new stars, which is why they were also named Pillars of Creation . The opacity of the fog is caused by silicate and carbon particles. The mean age of the stars is around 800,000 years. Some stars are very young; the age of the youngest stars is estimated to be 50,000 years.

discovery

The open star cluster was discovered by the Swiss astronomer Jean-Philippe de Chéseaux while mapping 21 nebulae in 1745 and 1746. The Eagle Nebula has number 4 in his list and was probably observed as early as 1745. In a letter to his father containing his list of 21 nebulae, he described the nebula as follows:

"A star cluster between the constellations Snake Bearer , Sagittarius and Antinous , whose right ascension is 271 ° 3 '10" and southern declination 13 ° 47' 20 "."

Regardless of Chéseaux's observations, since his list wasn't published until 1892, the French astronomer Charles Messier observed the same nebula about 18 years later. He entered his observation on June 3, 1764 in his Messier catalog. The observed star cluster is described in his catalog as "a cluster of tiny stars embedded in a faint glow". He also found that this star cluster "appears like a nebula in a smaller telescope". A direct observation of the nebula, as shown by the images from the Hubble Space Telescope , has not yet occurred. Messier probably described the nebula as "embedded in a faint glow" because the telescopes of the time did not have sufficient contrast performance. It was only much later that clear observations of the nebula were made and the first photographs were taken towards the beginning of the 20th century.

exploration

In 1995 the Hubble Space Telescope took pictures of this region, which revealed fascinating structures. For the first time, detailed insights into the formation processes of stars that have never been observed from this perspective before. The structure of these pillars resembles a bird of prey in a nosedive, which is how the fog got its name.

At the beginning of 2007, the Spitzer space telescope made recordings in the infrared range. These images showed the intact nebula, as we know it from the well-known images of the Hubble telescope, and a cloud of hot dust. It is believed that this cloud is the remnant of a star explosion or a supernova and that this cloud probably has enough power to change the shape of the molecular clouds that make up the popular pillars of creation. There is a possibility that this cloud of the supernova will drag the dust and gases out of the nebula with it and expose the young stars hidden in it and behind it. The associated supernova, which is considered to be the trigger for this event, was probably observed in the sky one to two thousand years ago. So, at a distance of seven thousand light years, the event is eight or nine thousand years in the past. Astronomers speculate that the pillars may have already been blown away, but due to the great distance and the time it takes for the light to travel (see the speed of light ) , we can still see the state of the nebula seven thousand years ago.

The infrared image of the Spitzertelescope: green the known fog structures; red the hot dust clouds of the supernova. The Hubble telescope holder is inserted in the box.
Image of a section of the Eagle Nebula using the line filter of the Hubble Space Telescope ( false color representation): The pillars of creation .
2006 Hubble image of part of the nebula