Astronomy:A1689-zD1

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Short description: Galaxy in the constellation Virgo
A1689-zD1
A1689-zD1.jpg
Observation data (J2000 epoch)
ConstellationVirgo
Right ascension 13h 11m 29.9s
Declination−01° 19′ 19″
Redshift7.6
Helio radial velocity2,278,423 km/s
Galactocentric velocity2,278,351 +/- 3 km/s
Distance13 billion light-years
(light travel distance)
30 billion light-years
(present proper distance)
Group or clusterAbell 1689
Apparent magnitude (V)25.3
Characteristics
TypeDwarf
Mass1.7×109 M
Size~3,000 ly (diameter)
Apparent size (V)0.0008 x 0.0008
Other designations
BBF2008 A1689-zD1

A1689-zD1 is a galaxy in the Virgo constellation. It was a candidate for the most distant and therefore earliest-observed galaxy discovered (As of February 2008), based on a photometric redshift.[1][2]

If the redshift, z~7.6,[3] is correct, it would explain why the galaxy's faint light reaches us at infrared wavelengths. It could only be observed with Hubble Space Telescope's Near Infrared Camera and Multi-Object Spectrometer (NICMOS) and the Spitzer Space Telescope's Infrared Array Camera exploiting the natural phenomenon of gravitational lensing: the galaxy cluster Abell 1689, which lies between Earth and A1689-zD1, at a distance of 2.2 billion light-years from us, functions as a natural "magnifying glass" for the light from the far more distant galaxy which lies directly behind it, at 700 million years after the Big Bang, as seen from Earth.[1]

See also

References