V399 Carinae
V399 Carinae (V399 Car, P Carinae, P Car, 195 G. Carinae) is a variable star in the constellation Carina.

The spectral type of V399 Carinae has been variously assigned between A5 and F0, being a bright, luminous supergiant. Its spectrum is described as having a non-photospheric continuum and silicon absorption lines, indicative of high mass loss.

V399 Carinae has long been suspected to be variable. A 1981 study of yellow supergiants fit observations to a Cepheid-like light curve with a period of 58.8 days, although the luminosity and spectral type do not place the star near the Cepheid instability strip. It was listed in the General Catalogue of Variable Stars as a possible δ Cep variable. Further observations refined the period to 47.25 days. The Hipparcos catalogue classified V399 Car as a semiregular variable with a period of 88 days and a mean amplitude of only 0.04 magnitudes. An automated classification from Hipparos photometry suggested it is an α Cygni variable. The observed brightness varies from magnitude +4.63 to +4.72.

V399 lies amongst the stars of the open cluster IC 2581, by far the brightest member of the cluster. It is about 7,500 light years from Earth assuming it is a member of IC 2581, which is given a 62.9% probability.
Q6243
variable star
Concept
Q8928
constellation
Concept
Q10470
Carina
CEL
Q25377588
spectral type
Concept
Q193599
luminous supergiant
Concept
Q752171
spectrum
Concept
Q212111
absorption line
Concept
Q280157
instability strip
Concept
Q222662
General Catalogue of Variable Stars
DIS
Q10451997
δ Cep variable
Concept
Q555846
Hipparcos
MISC
Q1054411
semiregular variable
CEL
Q622467
α Cygni variable
CEL
Q11387
open cluster
Concept
Q2
Earth
CEL
Q2609452
V399 Carinae
CEL
Q2609452
V399 Carinae
CEL
Q2609452
V399 Carinae
CEL
1981-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1981
DATE
2581-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
2581
DATE
2581-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
2581
DATE
+399^^http://www.w3.org/2001/XMLSchema#decimal
399
NUMBER
+399^^http://www.w3.org/2001/XMLSchema#decimal
399
NUMBER
+399^^http://www.w3.org/2001/XMLSchema#decimal
399
NUMBER
+5^^http://www.w3.org/2001/XMLSchema#decimal
5
NUMBER
0^^http://www.w3.org/2001/XMLSchema#decimal
0
NUMBER
+399^^http://www.w3.org/2001/XMLSchema#decimal
399
NUMBER
+58.8^^http://www.w3.org/2001/XMLSchema#decimal
58.8
NUMBER
+47.25^^http://www.w3.org/2001/XMLSchema#decimal
47.25
NUMBER
+399^^http://www.w3.org/2001/XMLSchema#decimal
399
NUMBER
+88^^http://www.w3.org/2001/XMLSchema#decimal
88
NUMBER
+0.04^^http://www.w3.org/2001/XMLSchema#decimal
0.04
NUMBER
++4.63^^http://www.w3.org/2001/XMLSchema#decimal
+4.63
NUMBER
++4.72^^http://www.w3.org/2001/XMLSchema#decimal
+4.72
NUMBER
+399^^http://www.w3.org/2001/XMLSchema#decimal
399
NUMBER
+62.9^^http://www.w3.org/2001/XMLSchema#decimal
62.9
NUMBER
constellation
type of variable star
instance of