3 Puppis

3 Puppis
	Location of 3 Puppis (circled)
Observation data; Epoch J2000 Equinox J2000
Constellation	Puppis
Right ascension	07h 43m 48.46872s
Declination	−28° 57′ 17.3720″
Apparent magnitude (V)	3.93
Characteristics
Spectral type	A2.7Ib (A2Ia - A3IIpe)
Apparent magnitude (K)	2.340
U−B color index	−0.09
B−V color index	+0.18
Astrometry
Radial velocity (Rv)	26.4±2.0 km/s
Proper motion (μ)	RA: −5.09 mas/yr ; Dec.: +3.90 mas/yr
Parallax (π)	0.59±0.17 mas
Distance	2,100±280 ly ; (630±85 pc)
Absolute magnitude (MV)	−5.5
Details
A
Mass	8.8±0.5 M☉
Radius	54±7 R☉
Luminosity	12,600+3,300; −2,600 L☉
Surface gravity (log g)	1.9±0.1 cgs
Temperature	8,500±500 K
Rotational velocity (v sin i)	35±5 km/s
B
Mass	0.75±0.25 M☉
Radius	0.3 R☉
Surface gravity (log g)	5.0 cgs
Temperature	50,000 K
Orbit
Primary	A
Companion	B
Period (P)	137.4±0.1 days
Semi-major axis (a)	1.11±0.03 AU
Semi-amplitude (K1); (primary)	5.0±0.8 km/s
Other designations
	l Puppis, GSC 06552-03228, HD 62623, HIP 37677, HR 2996, SAO 174400, CD−28°4774
Database references
SIMBAD	data

3 Puppis (3 Pup) is a spectroscopic binary in the constellation Puppis. It is a very rare A[e] supergiant, referred to as a B[e] star despite its spectral classification, and its apparent magnitude is 3.93.

Quick Facts Observation data Epoch J2000 Equinox J2000, Constellation ...

3 Puppis is surrounded by a disc of circumstellar dust, which is unusual for an A-type star.^[3] It is caused by a low mass companion, a helium-rich subdwarf that is transferring mass to the supergiant. Due to mass transfer, its mass reduced from 3.6 M_☉ when it formed to the current 0.75 M_☉.^[6] Like most B[e] stars, 3 Pup rotates rapidly, at 20%^[a] of the speed at which it would start to break apart. The disc has its inner edge only 3.8 AU from the primary star and it is suspected that deceleration of the hot primary stellar wind by the companion allows the dust to form unusually close to such a luminous star.^[3]

[1]

[2]

[3]

[4]

[5]

[6]

[a]

Observation data Epoch J2000 Equinox J2000
Location of 3 Puppis (circled)
Constellation	Puppis
Right ascension	07^h 43^m 48.46872^s^[1]
Declination	−28° 57′ 17.3720″^[1]
Apparent magnitude (V)	3.93^[2]
Characteristics
Spectral type	A2.7Ib^[2] (A2Ia - A3IIpe^[3])
Apparent magnitude (K)	2.340^[4]
U−B color index	−0.09^[5]
B−V color index	+0.18^[5]
Astrometry

Radial velocity (R_v)	26.4±2.0^[6] km/s
Proper motion (μ)	RA: −5.09 mas/yr^[1] Dec.: +3.90 mas/yr^[1]
Parallax (π)	0.59±0.17 mas^[1]
Distance	2,100±280 ly (630±85 pc)^[6]
Absolute magnitude (M_V)	−5.5^[2]

Details^[6]
A
Mass	8.8±0.5 `M`_☉
Radius	54±7 `R`_☉
Luminosity	12,600+3,300 −2,600 `L`_☉
Surface gravity (log g)	1.9±0.1 cgs
Temperature	8,500±500 K
Rotational velocity (v sin i)	35±5 km/s
B
Mass	0.75±0.25 `M`_☉
Radius	0.3 `R`_☉
Surface gravity (log g)	5.0 cgs
Temperature	50,000 K
Orbit^[6]
Primary	A
Companion	B
Period (P)	137.4±0.1 days
Semi-major axis (a)	1.11±0.03 AU
Semi-amplitude (K₁) (primary)	5.0±0.8 km/s
Other designations
l Puppis, GSC 06552-03228, HD 62623, HIP 37677, HR 2996, SAO 174400, CD−28°4774
Database references
SIMBAD	data

3 Puppis

Notes

References

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