OGLE-TR-123
OGLE-TR-123 is a binary stellar system containing one of the smallest main-sequence stars whose radius has been measured. It was discovered when the Optical Gravitational Lensing Experiment (OGLE) survey observed the smaller star eclipsing the larger primary. The orbital period is approximately 1.80 days. 

The smaller star, OGLE-TR-123b, is estimated to have a radius around 0.13 solar radii, and a mass of around 0.085 solar masses (), or approximately 90 times Jupiter's. OGLE-TR-123b's mass is close to the lowest possible mass, estimated to be around 0.07 or 0.08 , for a hydrogen-fusing star. OGLE-TR-123b is the second star with mass less than 0.1 whose radius has been directly measured; the first such star was the similar OGLE-TR-122b.
Q50053
binary
Concept
Q595871
stellar system
Concept
Q3450
main-sequence
Concept
Q523
star
Concept
Q173817
radius
Concept
Q1032158
Optical Gravitational Lensing Experiment
MISC
Q173817
radius
Concept
Q48440
solar radii
Concept
Q11423
mass
Concept
Q180892
solar mass
Concept
Q556
hydrogen
Concept
Q251121
OGLE-TR-122b
CEL
Q15096786
OGLE-TR-123
CEL
Q15096786
OGLE-TR-123
CEL
Q15096786
OGLE-TR-123
CEL
Q15096786
OGLE-TR-123
CEL
-123^^http://www.w3.org/2001/XMLSchema#decimal
-123
NUMBER
+1.80^^http://www.w3.org/2001/XMLSchema#decimal
1.80
NUMBER
-123^^http://www.w3.org/2001/XMLSchema#decimal
-123
NUMBER
+0.13^^http://www.w3.org/2001/XMLSchema#decimal
0.13
NUMBER
+0.085^^http://www.w3.org/2001/XMLSchema#decimal
0.085
NUMBER
+90^^http://www.w3.org/2001/XMLSchema#decimal
90
NUMBER
-123^^http://www.w3.org/2001/XMLSchema#decimal
-123
NUMBER
+0.07^^http://www.w3.org/2001/XMLSchema#decimal
0.07
NUMBER
+0.08^^http://www.w3.org/2001/XMLSchema#decimal
0.08
NUMBER
-123^^http://www.w3.org/2001/XMLSchema#decimal
-123
NUMBER
+0.1^^http://www.w3.org/2001/XMLSchema#decimal
0.1
NUMBER
-122^^http://www.w3.org/2001/XMLSchema#decimal
-122
NUMBER
instance of
part of
measured physical quantity