HD 95109

Last updated
HD 95109
Carina constellation map.svg
Red circle.svg
Location of U Carinae (circled)
Observation data
Epoch J2000        Equinox J2000
Constellation Carina
Right ascension 10h 57m 48.18690s [1]
Declination −59° 43 55.8872 [1]
Apparent magnitude  (V)5.72 - 6.90 [2]
Characteristics
Evolutionary stage Yellow supergiant
Spectral type F6-G7 Iab [2]
Variable type δ Cep [2]
Astrometry
Proper motion (μ)RA: −5.963  mas/yr [3]
Dec.: +2.397  mas/yr [3]
Parallax (π)0.553 ± 0.0226  mas [3]
Distance 6,187±218  ly
(1898±67  pc) [4]
Absolute magnitude  (MV)5.27 [5]
Details
Mass 7.5 - 11.7 [6]   M
Radius 187±5 [4]   R
Luminosity 26,642±1,584 [4]   L
Surface gravity (log g)1.2 [7]   cgs
Temperature 5,397 [4]  5,980 [7]   K
Metallicity +0.01 [8]
Age 29 [8]   Myr
Other designations
U  Car, CD 59°3448, HD  95109, HR  4276, HIP  52589
Database references
SIMBAD data

HD 95109 (U Carinae) is a Classical Cepheid variable, a type of variable star, in the constellation Carina. Its apparent magnitude is 6.86.

A near-infrared (J band) light curve for U Carinae, adpated from Laney and Stobie (1992) UCarLightCurve.png
A near-infrared (J band) light curve for U Carinae, adpated from Laney and Stobie (1992)

U Car is a δ Cepheid variable with a period of 38.7681 days. It was one of the earliest Cepheids to be discovered. It has also one of the longest periods, and hence is one of the most luminous in the class. [10] There are still only a few Cepheids with longer periods, including RS Puppis, SV Vulpeculae, and the unusual S Vulpeculae. [2]

The brightness variation in U Car is caused by fundamental mode pulsations. The radius and temperature both vary, with the radius changing by 42 R during each cycle. [11] The temperature variation causes the spectral type to vary between F6 and G7.

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<span class="mw-page-title-main">12 Vulpeculae</span> Star in the constellation Vulpecula

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<span class="mw-page-title-main">9 Vulpeculae</span> Star in the constellation Vulpecula

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<span class="mw-page-title-main">S Vulpeculae</span> Variable star in the constellation Vulpecula

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<span class="mw-page-title-main">SV Vulpeculae</span> Star in the constellation Vulpecula

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<span class="mw-page-title-main">U Vulpeculae</span> Variable star in the constellation Vulpecula

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<span class="mw-page-title-main">SX Centauri</span> Supergiant variable star in the constellation Centaurus

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References

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