We report the discovery of the molecular cloud whose kinematic distance is the largest in the Galaxy at the present moment , named G213.042 + 0.003 , at l = \timeform 213.042D and b = \timeform 0.003D in the \atom C12 \atom O ( J = 1–0 ) line using the Nobeyama 45-m telescope and a multi-beam receiver BEARS .
This molecular cloud is located at the heliocentric distance of 21 _ { -7 } ^ { +12 } kpc and Galactocentric distance of 29 _ { -7 } ^ { +12 } kpc , which are estimated as the kinematic distances with the Galactic parameters obtained by Reid et al .
( 2014 , ApJ , 783 , 130 ) .
Its major and minor diameters and line width were measured to be 4.0 _ { -1.3 } ^ { +2.3 } pc , 3.0 _ { -1.0 } ^ { +1.7 } pc , and 1.5 km s ^ { -1 } , respectively .
The cloud mass was estimated to be 2.5 _ { -1.4 } ^ { +3.7 } \times 10 ^ { 2 } \Mo using the \atom C \atom O-to- \atom H _ { 2 } conversion factor of 5.6 \times 10 ^ { 20 } cm ^ { -2 } ( K km s ^ { -1 } ) ^ { -1 } obtained in far outer Galaxy .