Mercer 3, also known as GLIMPSE-C02, is a heavily obscured globular cluster embedded in the disk of the Milky Way galaxy. It was discovered in 2008 in the data obtained by

2MASS The Two Micron All-Sky Survey, or 2MASS, was an astronomical survey of the whole sky in infrared light. It took place between 1997 and 2001, in two different locations: at the U.S. Fred Lawrence Whipple Observatory on Mount Hopkins, Arizona, and ...

and

GLIMPSE Glimpse or Glimpses may refer to: * Glimpse: Live Recordings from Around the World, an album by Sonicflood * ''The Glimpse'', an album by Robert Mitchell * Glimpse EP, an album by Trapt *Glimpse (software), a photo editor forked from GIMP GLIMPS ...

infrared surveys, and independently characterized by two groups. The cluster is located in the

Scutum The ''scutum'' (; plural ''scuta'') was a type of shield used among Italic peoples in antiquity, most notably by the army of ancient Rome starting about the fourth century BC. The Romans adopted it when they switched from the military formati ...

constellation. It had avoided detection for such a long time due to the extremely strong foreground extinction (astronomy), extinction in its direction reaching 24 magnitudes in the visible light. Mercer 3 is probably situated at the distance from 4 to 8 Parsec#Parsecs and kiloparsecs, kpc from the Sun and has a half-light radius of 0.7–1.5 pc. Mercer 3 is an old globular cluster having the age of about 12 billion years. The mass of cluster is estimated at 2–3 hundred thousand solar masses. It is among the most metallicity, metal-rich galactic globular clusters known.

References

{{DEFAULTSORT:Mercer 3 Globular clusters Scutum (constellation)