Collinder 135, known sometimes as the Pi Puppis Cluster, is an open cluster in Puppis constellation.

Collinder 135
Observation data (2000.0 epoch)
Right ascension	07h 08m [1]
Declination	−37° 10′[1]
Distance	1,040.5 ly (319 pc [1])
Apparent magnitude (V)	2.1[1]
Apparent dimensions (V)	50'
Physical characteristics
Other designations	Pi Puppis Cluster, Cr 135, C 0715-367
Associations
Constellation	Puppis
See also: Open cluster, List of open clusters

It consists of six stars brighter than 6th magnitude, and a widespread population of fainter stars.^[2] It lies in the southern celestial hemisphere near a rich star field. The main component is the star Pi Puppis, which gives to the cluster its common name; it is an orange supergiant with a visual magnitude of 2.71. Two of the 5th magnitude stars are all variables: NV Puppis is a Gamma Cassiopeiae variable, while NW Puppis is a Beta Cephei variable.