HD 137509

Last updated
HD 137509
HD137509LightCurve.png
The visual band light curve of HD 137509, adapted from Lanz & Mathys (1991) [1]
Observation data
Epoch J2000       Equinox J2000
Constellation Apus
Right ascension 15h 31m 27.11494s [2]
Declination −71° 03′ 43.6643″ [2]
Apparent magnitude  (V)6.89 [3]
Characteristics
Spectral type B9p (SiCrFe) [4]
B8 He wk SiCrFe [5]
B−V color index −0.125±0.004 [3]
Variable type α2 CVn [6]
Astrometry
Radial velocity (Rv)+0.50 [7]  km/s
Proper motion (μ)RA: −16.276 [2]   mas/yr
Dec.: −15.503 [2]   mas/yr
Parallax (π)5.0410 ± 0.0503  mas [2]
Distance 647 ± 6  ly
(198 ± 2  pc)
Absolute magnitude  (MV)0.45 [3]
Details
Mass 3.43±0.17 [8]   M☉
Radius 2.81 [9]   R☉
Luminosity 123 [3]   L☉
Surface gravity (log g)4.3 [5]   cgs
Temperature 13,100±500 [5]   K
Rotation 4.492 d [8]
Rotational velocity (v sin i)20±2 [5]  km/s
Age 124 [10]   Myr
Other designations
NN Aps, CD−70°1302, GC  20810, HD  137509, HIP  76011, SAO  257290 [11]
Database references
SIMBAD data

HD 137509 is a star in the southern constellation of Apus, positioned less than a degree from the northern constellation boundary with Triangulum Australe. [12] It has the variable star designation of NN Apodis, or NN Aps for short, and ranges in brightness from an apparent visual magnitude of 6.86 down to 6.93 with a period of 4.4916 days. [6] The star is located at a distance of approximately 647  light years from the Sun based on parallax, and is drifting further away with a radial velocity of +0.50 km/s. [7]

In 1973, W. P. Bidelman and D. J. MacConnell found this to be a peculiar A star of the silicon type. [13] During a reclassification of the spectra of southern stars in 1975, A. P. Cowley and N. Houk noted the strength of hydrogen lines and weakness of helium are more typical of a class near B9. It shows a luminosity above the main sequence, which is common for a peculiar A star. The stellar atmosphere appears deficient in helium, but shows a rich variety of metallic lines. However, there are no lines of manganese or mercury, so it's not a Hg–Mn Ap star. [14] HD 137509 is now classified as B9p (SiCrFe) [4] or B8 He wk SiCrFe, [5] matching a late-type, helium-weak Bp star with overabundances of silicon, chromium, and iron.

This star was found to be photometrically variable by L. O. Lodén and A. Sundman in 1989, and a variable spectrum was noted by H. Pedersen in 1979. [13] It has one of the strongest magnetic fields recorded for a chemically peculiar star, measured at around 29  kG , [4] and shows a strong quadrupolar component. [15] Both variances of the star allow its rotation period to be precisely measured. [13] It is classified as a Alpha2 Canum Venaticorum variable. [6] The star is about 124 [10]  million years old with 3.4 [8] times the mass of the Sun and 2.8 [9] times the Sun's radius. On average it is radiating ~123 [3] times the luminosity of the Sun from its photosphere at an effective temperature of 13,100 K. [5]

Related Research Articles

<span class="mw-page-title-main">56 Arietis</span> Star in the constellation Aries

56 Arietis is a single, variable star in the northern zodiac constellation of Aries. It has the variable star designation SX Arietis, while 56 Arietis is the Flamsteed designation. This object is visible to the naked eye as a faint, blue-white hued point of light with a baseline apparent visual magnitude of 5.79. The estimated distance to this star is approximately 415 light-years, based on parallax, and it is drifting further away with a radial velocity of +18 km/s.

<span class="mw-page-title-main">12 Canis Majoris</span> Variable star in the constellation Canis Major

12 Canis Majoris is a variable star located about 707 light years away from the Sun in the southern constellation of Canis Major. It has the variable star designation HK Canis Majoris; 12 Canis Majoris is the Flamsteed designation. This body is just barely visible to the naked eye as a dim, blue-white hued star with a baseline apparent visual magnitude of +6.07. It is moving away from the Earth with a heliocentric radial velocity of +16 km/s. This is the brightest star in the vicinity of the open cluster NGC 2287, although it is probably not a member based on its proper motion.

<span class="mw-page-title-main">26 Canis Majoris</span> Star in the constellation Canis Major

26 Canis Majoris is a variable star in the southern constellation of Canis Major, located around 1,010 light years away from the Sun. It has the variable star designation MM Canis Majoris; 26 Canis Majoris is the Flamsteed designation. This object is visible to the naked eye as a dim, blue-white hued star with a baseline apparent visual magnitude of 5.89. It is moving further from the Earth with a heliocentric radial velocity of +22 km/s.

<span class="mw-page-title-main">HD 125823</span> Star in the constellation Centaurus

HD 125823, also known as V761 Centauri or a Centauri, is a variable star in the constellation Centaurus. It is a blue-white star that is visible to the naked eye with a mean apparent visual magnitude of +4.41. The distance to this star is approximately 460 light years based on parallax measurements. It is a member of the Upper Centaurus–Lupus subgroup of the Scorpius–Centaurus association.

<span class="mw-page-title-main">HD 37017</span> Binary star system in the constellation Orion

HD 37017 is a binary star system in the equatorial constellation of Orion. It has the variable star designation V1046 Orionis; HD 37017 is the identifier from the Henry Draper Catalogue. The system is a challenge to view with the naked eye, being close to the lower limit of visibility with a combined apparent visual magnitude of 6.55. It is located at a distance of approximately 1,230 light years based on parallax, and is drifting further away with a radial velocity of +32 km/s. The system is part of star cluster NGC 1981.

<span class="mw-page-title-main">ET Andromedae</span> Star in the constellation Andromeda

ET Andromedae is a binary star system star in the northern constellation of Andromeda. It has an apparent visual magnitude of 6.48, placing it at the nominal limit for visibility with the naked eye. The distance to this system can be estimated from its annual parallax shift of 5.42 mas, which yields a value of 602 light years.

VZ Arietis is single, white-hued star in the northern zodiac constellation of Aries. Varying between magnitudes 5.82 and 5.89, the star can be seen with the naked eye in dark, unpolluted areas. Based upon an annual parallax shift of 5.8 mas, it is located 560 light years from the Sun. It is moving further away with a heliocentric radial velocity of +14 km/s. The star was formerly known as 16 Trianguli, but as the star is no longer in the constellation Triangulum, this designation has fallen out of use.

<span class="mw-page-title-main">BX Boötis</span> Star in the constellation Boötes

BX Boötis is a star in the northern constellation of Boötes. It is a dim star near the lower limit of visibility to the naked eye, having a nominal apparent visual magnitude of 6.35. Based upon an annual parallax shift of 10.81 mas, it is located 302 light years away. At that distance, the visual magnitude of the star is diminished by an extinction of 0.13 due to interstellar dust. It is moving closer with a heliocentric radial velocity of −11 km/s.

HR 3082 is a double star in the northern circumpolar constellation of Camelopardalis. It is faintly visible to the naked eye with an apparent visual magnitude of 5.39. The system is moving closer to the Sun with a heliocentric radial velocity of +2.7 km/s. It is currently at a distance of around 341 light years, based upon an annual parallax shift of 9.57 mas.

<span class="mw-page-title-main">BN Camelopardalis</span> Star in the constellation Camelopardalis

BN Camelopardalis is a suspected astrometric binary in the northern circumpolar constellation of Camelopardalis. It appears as a variable star that is visible to the naked eye as a dim, white-hued point of light with an apparent visual magnitude that fluctuates around 5.49. The system is located at a distance of around 310 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +9 km/s.

<span class="mw-page-title-main">45 Herculis</span> Star in the constellation Hercules

45 Herculis is a solitary variable star in the northern constellation Hercules. It has the Bayer designation l Herculis and the variable star designation V776 Herculis. The Flamsteed designation for this star comes from the publication Historia Coelestis Britannica by John Flamsteed. It is the 45th star in Flamsteed list of stars in the constellation Hercules, and is visible to the naked eye with a baseline apparent visual magnitude of 5.22. Parallax measurements show this star to be about 400 light-years away from the Solar System. It is moving closer to the Earth with a heliocentric radial velocity of −16 km/s.

<span class="mw-page-title-main">CU Virginis</span> Star in the constellation Virgo

CU Virginis is a single star in the equatorial constellation of Virgo. It has an apparent visual magnitude of 4.99, which is bright enough to be faintly visible to the naked eye. The distance to this star can be estimated from its annual parallax shift of 13.9 mas, yielding a separation of 234 light years.

4 Cygni is a binary star system in the northern constellation of Cygnus. It is a faintly visible to the naked eye with an apparent visual magnitude of 5.17. The distance to 4 Cygni, as determined from its annual parallax shift of 5.8 mas, is about 560 light years.

<span class="mw-page-title-main">36 Lyncis</span> Star in the constellation Lynx

36 Lyncis is a solitary variable star located around 620 light years away from the Sun in the northern constellation of Lynx. It has the variable star designation of EI Lyncis, while 36 Lyncis is the Flamsteed designation. This object is visible to the naked eye as a dim, blue-white hued star with an apparent visual magnitude of 5.30. It is moving further away from the Earth with a heliocentric radial velocity of 21 km/s.

Theta Hydri, Latinized from θ Hydri, is the Bayer designation for a blue-white hued star in the southern constellation of Hydrus. It is faintly visible to the naked eye with an apparent visual magnitude of +5.53. Based upon an annual parallax shift of 6.50 mas as seen from Earth, is located approximately 502 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction of 0.10 due to interstellar dust. It is moving away from the Sun with a radial velocity of +12.3 km/s.

<span class="mw-page-title-main">19 Lyrae</span> Star in the constellation Lyra

19 Lyrae is a single variable star located approximately 950 light years away from the Sun in the northern constellation of Lyra. It has the variable star designation V471 Lyr, while 19 Lyrae is the Flamsteed designation. This object is just bright enough to be visible to the naked eye, appearing as a dim, blue-white star with a baseline apparent visual magnitude of 5.93. It is moving closer to the Earth with a heliocentric radial velocity of −30 km/s, and may come as close as 167 light-years around 8.5 million years from now.

<span class="mw-page-title-main">HD 125248</span> Binary star system in the constellation of Virgo

HD 125248 is a binary star system in the equatorial constellation of Virgo. It has the variable star designation CS Virginis, while HD 125248 is the designation from the Henry Draper Catalogue. This system is dimly visible to the naked eye as a point of light with an apparent visual magnitude that ranges from 5.84 down to 5.95. It is located at a distance of approximately 280 light years from the Sun based on parallax measurements, but is drifting closer with a heliocentric radial velocity of −8 km/s.

<span class="mw-page-title-main">HR 1217</span> Star in the constellation Eridanus

HR 1217 is a variable star in the constellation Eridanus. It has the variable star designation DO Eridani, but this seldom appears in the astronomical literature; it is usually called either HR 1217 or HD 24712. At its brightest, HR 1217 has an apparent magnitude of 5.97, making it very faintly visible to the naked eye for an observer with excellent dark-sky conditions.

<span class="mw-page-title-main">V686 Coronae Australis</span> Alpha2 CVn variable; Corona Australis

V686 Coronae Australis is a solitary, bluish-white-hued variable star located in the southern constellation Corona Australis. It has an apparent magnitude that ranges between 5.25 and 5.41, which makes it faintly visible to the naked eye. Gaia DR3 parallax measurements imply a distance of 480 light years and it is slowly receding with a heliocentric radial velocity of 1.3 km/s. At its current distance V686 CrA's average brightness is diminished by 0.35 magnitudes due to extinction from interstellar dust and it has an absolute visual magnitude of −0.24.

<span class="mw-page-title-main">25 Sextantis</span> Alpha2 Canum Venactiorum variable.

25 Sextantis, or simply 25 Sex, is a star located in the equatorial constellation Sextans; it also bears the variable star designation SS Sextantis. With an average apparent magnitude of 5.97, 25 Sex is barely visible to the naked eye, even under ideal conditions. Gaia DR3 parallax measurements imply a distance of 345 light-years, and it is currently drifting away with a heliocentric radial velocity of approximately 23 km/s. At its current distance, 25 Sex's average brightness is diminished by an interstellar extinction of 0.17 magnitudes and it has an absolute magnitude of +0.86.

References

  1. ↑ Lanz, T.; Mathys, G. (August 1991). "The Photometric Variability of the B9p Star HD 137509". Information Bulletin on Variable Stars. 3655: 1. Bibcode:1991IBVS.3655....1L.
  2. 1 2 3 4 5 Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics . 616. A1. arXiv: 1804.09365 . Bibcode: 2018A&A...616A...1G . doi: 10.1051/0004-6361/201833051 . Gaia DR2 record for this source at VizieR.
  3. 1 2 3 4 5 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv: 1108.4971 . Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID   119257644.
  4. 1 2 3 Shulyak, D.; et al. (2008). "Model atmospheres of magnetic chemically peculiar stars. A remarkable strong-field Bp SiCrFe star HD 137509". Astronomy and Astrophysics. 487 (2): 689–96. arXiv: 0806.1296 . Bibcode:2008A&A...487..689S. doi:10.1051/0004-6361:20079134. S2CID   14113957.
  5. 1 2 3 4 5 6 Bailey, J. D.; Landstreet, J. D. (2013). "Abundances determined using Si ii and Si iii in B-type stars: Evidence for stratification". Astronomy & Astrophysics. 551: A30. arXiv: 1301.3050 . Bibcode:2013A&A...551A..30B. doi:10.1051/0004-6361/201220671. S2CID   59291051.
  6. 1 2 3 Samus', N. N; Kazarovets, E. V; Durlevich, O. V; Kireeva, N. N; Pastukhova, E. N (2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID   125853869.
  7. 1 2 Barbier-Brossat, M.; Petit, M.; Figon, P. (December 1994). "Third bibliographic catalogue of stellar radial velocities". Astronomy and Astrophysics Supplement. 108: 603–609. Bibcode:1994A&AS..108..603B.
  8. 1 2 3 Netopil, Martin; et al. (July 2017). "An investigation of the rotational properties of magnetic chemically peculiar stars". Monthly Notices of the Royal Astronomical Society. 468 (3): 2745–2756. arXiv: 1703.05218 . Bibcode:2017MNRAS.468.2745N. doi: 10.1093/mnras/stx674 .
  9. 1 2 Shulyak, D.; et al. (2014). "Interferometry of chemically peculiar stars: Theoretical predictions versus modern observing facilities". Monthly Notices of the Royal Astronomical Society. 443 (2): 1629. arXiv: 1406.6093 . Bibcode:2014MNRAS.443.1629S. doi: 10.1093/mnras/stu1259 . S2CID   96452769.
  10. 1 2 Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters, 38 (11): 694–706, arXiv: 1606.09028 , Bibcode:2012AstL...38..694G, doi:10.1134/S1063773712110035, S2CID   119108982
  11. ↑ "9 Cet". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2020-12-27.
  12. ↑ Sinnott, Roger W.; Perryman, Michael A. C. (1997). Millennium Star Atlas. Vol. 2. Sky Publishing Corporation and the European Space Agency. p. 1009. ISBN   0-933346-83-2.
  13. 1 2 3 Mathys, G.; Lanz, T. (July 1997). "The variations of the BP star HD 137509". Astronomy and Astrophysics. 323: 881–885. Bibcode:1997A&A...323..881M.
  14. ↑ Cowley, A. P.; Houk, N. (August 1975). "An interesting new southern peculiar A star - HD 137509". Publications of the Astronomical Society of the Pacific. 87: 527–528. Bibcode:1975PASP...87..527C. doi: 10.1086/129803 .
  15. ↑ Kochukhov, O. (July 2006). "Remarkable non-dipolar magnetic field of the Bp star HD 137509". Astronomy and Astrophysics. 454 (1): 321–325. arXiv: astro-ph/0603831 . Bibcode:2006A&A...454..321K. doi:10.1051/0004-6361:20064932. S2CID   17058487.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.