V4024 Sagittarii

V4024 Sagittarii

A light curve for V4024 Sagittarii, plotted from Hipparcos data[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Sagittarius
Right ascension 19h 08m 16.70187s[2]
Declination −19° 17′ 25.0380″[2]
Apparent magnitude (V) 5.34 - 5.60[3]
Characteristics
Spectral type B2Ve[4]
B−V color index −0.06[5]
Variable type γ Cas[3]
Astrometry
Radial velocity (Rv)−20.3±2.9[6] km/s
Proper motion (μ) RA: +6.240[2] mas/yr
Dec.: −1.126[2] mas/yr
Parallax (π)2.3734 ± 0.1406 mas[2]
Distance1,370 ± 80 ly
(420 ± 20 pc)
Absolute magnitude (MV)−2.39[6]
Details[7]
Mass8.8±0.6 M☉
Radius4.5[8] R☉
Luminosity (bolometric)7,551+1,119
−974 L☉
Surface gravity (log g)3.24±0.49 cgs
Temperature18,100±500 K
Rotational velocity (v sin i)105±10 km/s
Age25.1±1.3[9] Myr
Other designations
V4024 Sgr, BD−19°5312, HD 178175, HIP 93996, HR 7249, SAO 162229[10]
Database references
SIMBADdata

V4024 Sagittarii is a single[11] variable star in the southern constellation of Sagittarius. It has a blue-white hue and is dimly visible to the naked eye with an apparent visual magnitude that fluctuates from about 5.3 to 5.6. The star is located at a distance of approximately 1,700 light years based on stellar parallax, but is drifting closer with a radial velocity of −20 km/s. The position of this star near the ecliptic means it is subject to lunar occultations.[12]

This object is a massive Be star with a stellar classification of B2Ve.[4] The 'e' suffix indicates the spectrum of the star displays emission lines, which are created by materials ejected from the equatorial region of this rapidly rotating star. It is classified as an eruptive Gamma Cassiopeiae variable and has been measured ranging in brightness from visual magnitude 5.34 down to 5.60.[3] The star is an estimated 5 million years old with 8.8 times the mass of the Sun[9] and about 4.5[8] times the Sun's radius. It is spinning with a projected rotational velocity of 105 m/s. V4024 Sagittarii is radiating 7,551 times the luminosity of the Sun from its photosphere at an effective temperature of 18,100 K.[7] Koen and Eyer examined the Hipparcos data for this star, and found that its brightness varied with a period of 1.7733 days.[13]

  1. ^ Cite error: The named reference CDS was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Jaschek1992 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Chauville2001 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Zorec2016 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Fracassini2001 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Mason1996 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Koen was invoked but never defined (see the help page).