2MASS

In infrared astronomy of the Two Micron All Sky Survey (called short 2MASS ), a major survey of the entire sky in the near infrared at wavelengths of 1.25 microns ( in the J- band ), 1.65 microns ( in the H- band ) and 2, 17 microns ( in the Ks- band).

2MASS was performed on two particularly purpose-built automated 1.3 - m telescopes - for the northern sky at the Fred Lawrence Whipple Observatory in Arizona and the southern sky at Cerro Tololo Inter- American Observatory in Chile. Telescopes possessed cameras having three channels, with a 256 x 256 -element HgCdTe - detector for each of the three wavelengths. The observations started in 1997 and ended in 2001. 2MASS is a joint project of the University of Massachusetts ( UMASS ) and the Infrared Processing and Analysis Center ( IPAC ) at the California Institute of Technology.

2MASS produced very large and homogeneous data sets that are available for many astronomical problems of significance. These include:

• A digital atlas of the entire sky in the near infrared with a resolution of 4 arc seconds
• A point source catalog of positions and magnitudes for about 470 million stars and other unresolved objects
• A catalog of extended sources with positions and magnitudes of about 1.6 million galaxies and other extended objects.