Arp-Madore 1

Arp-Madore 1 (also known as AM 1) is a globular cluster visible in the constellation Horologium, located 123.3 kiloparsecs (402,000 light-years) away from Earth.^[2] It is one of the most distant known globular clusters of the Milky Way galaxy's halo;^[3][4] its distance gives it interest as a test case for gravitational theories.^[5] AM 1 has a visual magnitude of 15.07.^[6]

Arp-Madore 1
Globular cluster Arp-Madore 1
Observation data (J2000.0 epoch)
Constellation	Horologium
Right ascension	03h 55m 02.70s[1]
Declination	−49° 36′ 52.0″[1]
Distance	398,000 (122,000)
Apparent magnitude (V)	15.07
Apparent dimensions (V)	1.288 by 0.691 ′[1]
Physical characteristics
Other designations	E1, AM 0353-094, C 0353-497, C 0354-498, AM 1, ESO 201-10, LEDA 14098, SGC 035336-4945.6[1]
See also: Globular cluster, List of globular clusters

It is named after Halton Arp and Barry F. Madore, who identified it as a distant globular cluster in 1979, using the UK Schmidt Telescope,^[7] after previous researchers at the European Southern Observatory had observed its existence but not its classification.^[8]

See also

• Arp-Madore 2