Upsilon1 Cancri

Upsilon¹ Cancri is a solitary,^[4] yellow-white-hued star in the constellation Cancer. Its name is a Bayer designation that is Latinized from υ¹ Cancri, and abbreviated Upsilon¹ Cnc or υ¹ Cnc. This star is faintly visible to the naked eye, having an apparent visual magnitude of +5.7.^[3] Based upon an annual parallax shift of 13.62 mas as seen from Earth,^[2] this system is 240 light-years (73 pc) distant from the Sun. It is drifting further away with a line of sight velocity of +19 km/s.^[5]

For other stars with this Bayer designation, see υ Cancri.

Upsilon¹ Cancri

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Cancer[1]
Right ascension	08h 31m 30.519s[2]
Declination	+24° 04′ 51.99″[2]
Apparent magnitude (V)	+5.694[3]
Characteristics
Spectral type	F0 IIIn[4]
B−V color index	+0.309[3]
Astrometry
Radial velocity (Rv)	+19.0±4.3[5] km/s
Proper motion (μ)	RA: −80.791 mas/yr[2] Dec.: −44.858 mas/yr[2]
Parallax (π)	13.6180±0.0415 mas[2]
Distance	239.5 ± 0.7 ly (73.4 ± 0.2 pc)
Absolute magnitude (MV)	+1.29[1]
Details
Mass	1.47[6] M☉
Radius	3.20±0.02[2] R☉
Luminosity	25[1] L☉
Surface gravity (log g)	3.51[7] cgs
Temperature	7,240±246[6] K
Rotational velocity (v sin i)	109.2[7] km/s
Age	570[6] Myr
Other designations
υ1 Cnc, 30 Cancri, BD+24°1940, FK5 2666, HD 72041, HIP 41816, HR 3355, SAO 80229[8]
Database references
SIMBAD	data

This object has a stellar classification of F0 IIIn, presenting as an F-type giant star.^[4] The 'n' suffix indicates "nebulous" absorption lines due to rapid rotation, and it shows a relatively high projected rotational velocity of 109.2 km/s.^[7] It is a variable star of unknown type that changes brightness with an amplitude of 0.05 magnitude.^[9] The star is about 570^[6] million years old and is spinning rapidly with a projected rotational velocity of 109.2 km/s.^[7] It has an estimated mass of 1.47^[6] times that of the Sun and 3.2 times the Sun's radius.^[2] On average, it is radiating 25^[1] times the Sun's luminosity from its photosphere at an effective temperature of 7,240 K.^[6]