QQ Telescopii

QQ Telescopii
Location of QQ Telescopii (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Telescopium
Right ascension 19h 39m 41.77938s[1]
Declination −45° 16′ 42.7871″[1]
Apparent magnitude (V) 6.25[2]
Characteristics
Spectral type F2 IV[3] or F0 III:[4]
B−V color index +0.28[2]
Variable type δ Scuti[5]
Astrometry
Radial velocity (Rv)7.8±1.5[6] km/s
Proper motion (μ) RA: −22.160 mas/yr[1]
Dec.: +5.375 mas/yr[1]
Parallax (π)9.8017 ± 0.0327 mas[1]
Distance333 ± 1 ly
(102.0 ± 0.3 pc)
Absolute magnitude (MV)+1.01[7]
Details
Mass1.68[8] M☉
Radius3.19±0.16[9] R☉
Luminosity26.1±0.2[1] L☉
Surface gravity (log g)3.73±0.12[10] cgs
Temperature7,380±136[11] K
Metallicity [Fe/H]+0.07±0.15[12] dex
Rotational velocity (v sin i)45±5[13] km/s
Age995+121
−120[1] Myr
Other designations
66 G. Telescopii[14], QQ Tel, CD−45°13354, CPD−45°9764, GC 27167, HD 185139, HIP 96721, HR 7461, SAO 229800[15]
Database references
SIMBADdata

QQ Telescopii, also known as HD 185139 or simply QQ Tel, is a solitary variable star located in the southern constellation Telescopium. It has an apparent magnitude of 6.25,[2] placing it near the limit for naked eye visibility, even under ideal conditions. Gaia DR3 parallax measurements imply a distance of 333 light years[1] and it is currently receding with a heliocentric radial velocity of 7.8 km/s.[6] At its current distance, QQ Telescopii's brightness is diminished by two tenths of a magnitude due to interstellar dust[16] and it has an absolute magnitude of +1.01.[7]

A light curve for QQ Telescopii, plotted from TESS data[17]

HD 185139 was discovered to be a δ Scuti variable in 1982 by Debora W. Kurtz along with HR 151 (BG Ceti).[18] After a few years of subsequent observations, it was given the variable designation QQ Telescopii in 1985.[19] In 2002, C. Koen and colleagues attempted to identify the pulsation modes of the star.[13] The brightness of QQ Tel fluctuates by about 0.05 magnitudes in the blue passband within 1.56 hours.[5]

QQ Telescopii has a stellar classification of F2 IV,[3] indicating that it is a slightly evolved F-type subgiant. It was previously classified as kA6mF0 III[20] and A0pSr(CrSi),[21] indicating that it is either a chemically peculiar Ap star or Am star. However, Renson & Manfroid (2009) considers its chemical peculiarity to be doubtful.[22] Andersen & Nordstöm (1978) give it a class of F0 III:,[4] indicating that it is an evolved F-type giant star with uncertainty about the luminosity class. Evolutionary models place it very close to the end of its main sequence life.[1]

With 1.68 times the mass of the Sun[8] and an enlarged radius 3.19 times that of the Sun,[9] QQ Telescopii radiates 26.1 times the luminosity of the Sun[1] from its photosphere at an effective temperature of 7,380 K,[11] giving it a yellowish-white hue. It is slightly metal enriched at [Fe/H] = +0.07[12] but the value is poorly constrained. The star is estimated to be 995 million years old[1] and it spins modestly with a projected rotational velocity of 45 km/s.[13]

  1. ^ a b c d e f g h i j Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference Johnson1966 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Houk1978 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Andersen1978 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Yang2022 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Kervella2004 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference A.P1999 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference Stassun2019 was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference Paunzen2002 was invoked but never defined (see the help page).
  13. ^ a b c Cite error: The named reference Koen2003 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Gould1879 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference Gontcharov2017 was invoked but never defined (see the help page).
  17. ^ Cite error: The named reference MAST was invoked but never defined (see the help page).
  18. ^ Cite error: The named reference Kurtz1983 was invoked but never defined (see the help page).
  19. ^ Cite error: The named reference Kholopov1985 was invoked but never defined (see the help page).
  20. ^ Cite error: The named reference Hoffleit1953 was invoked but never defined (see the help page).
  21. ^ Cite error: The named reference Brandi1973 was invoked but never defined (see the help page).
  22. ^ Cite error: The named reference Renson2009 was invoked but never defined (see the help page).