Wikipedia

HD 161056

HD 161056 (HIP 86768, HR 6601) is a bluish-white hued star in the equatorial constellation of Ophiuchus. It has an apparent magnitude of 6.32, placing it near the limit for naked eye visibility under dark skies. The object is located approximately 1,340 light-years (410 parsecs) distant according to Gaia EDR3 parallax measurements,[1] but it is moving closer at a heliocentric radial velocity of −26.0 km/s.

HD 161056
Location of HD 161056 (circled)
Observation data
Epoch J2000.0[1]      Equinox J2000.0[1]
Constellation Ophiuchus
Right ascension 17h 43m 47.02216s
Declination −07° 04′ 46.5943″
Apparent magnitude (V) 6.32[2]
Characteristics
Spectral type B1.5V, B3II/III, or B3Vn[3]
U−B color index −0.42[2]
B−V color index 0.36[2]
J−H color index 0.072[4]
J−K color index 0.101[4]
Astrometry
Radial velocity (Rv)−26.0±4.3[5] km/s
Proper motion (μ) RA: -4.629[1] mas/yr
Dec.: −10.512[1] mas/yr
Parallax (π)2.4404 ± 0.0432 mas[1]
Distance1,340 ± 20 ly
(410 ± 7 pc)
Other designations
BD−07° 4487, Gaia DR3 4168881422863453568, GC 24051, HIP 86768, HR 6601, SAO 141832, PPM 200979, TIC 296910097, TYC 5093-438-1, 2MASS J17434702-0704465[4]
Database references
SIMBADdata

It is a luminous early B-type star, but its spectral type varies from publication to publication, most often between B1.5V,[6] implying a hot main-sequence star, and B3II/III,[7] indicative of a slightly cooler blue giant.

In Chinese astronomy, the star was given the name Shìlóuliù (Chinese: 市樓六), meaning it was the sixth star of the asterism Shìlóu (市樓, "Municipal Office") in the Heavenly Market enclosure.[8]

Polarimetry

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In 1985, the star was suggested as a standard for polarimetric observations via the Hubble Space Telescope, since the star's large distance from Earth produces a large interstellar polarization and its high luminosity makes it easily visible at such distances. In 1988, however, it was found that the star was slightly variable in polarization,[a] and thus unsuitable as a standard star.[9]

Nevertheless, Hubble observed the star's ultraviolet interstellar polarization, thanks to it having been well-researched in the visible spectrum, presenting results consistent with Serkowski's law[10]—an empirical formula regarding the dependency of interstellar polarization on wavelength.[11] The extensive collected polarization spectrum showed a close match to what would be expected from an interstellar dust composition of pure amorphous forsterite.[12]

Spectroscopy

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In addition to polarimetry, spectroscopic observations have also been conducted on HD 161056 to provide insight into the interstellar medium. The ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES) detected signatures of diatomic carbon and tricarbon molecules in interstellar clouds surrounding the star.[13]

Near-infrared spectroscopy has revealed signs of weak stellar emission lines of doubly ionized magnesium and singly ionized helium.[14]

Runaway star

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HD 161056 is a runaway star and a candidate for producing a bow shock observable in the infrared.[15] Such stars commonly originate in multiple star systems, from which they were ejected due to gravitational interactions or supernovae of their companions,[16] and indeed it is possible that the star could have been in a binary system with the pulsar PSR B1929+10 about 1.1 million years ago, when it was located in the vicinity of IC 4665. However, Zeta Ophiuchi is considered more likely to have been its binary companion, in which scenario the pair possibly split up around 900,000 years ago.[17]

See also

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Notes

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  1. ^ The same authors backed the star's status down to "possibly variable" in a 2007 study.[6]

References

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  1. ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  2. ^ a b c Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
  3. ^ Pantaleoni González, M; Maíz Apellániz, J; Barbá, R H; Reed, B Cameron (19 March 2021). "The Alma catalogue of OB stars – II. A cross-match with Gaia DR2 and an updated map of the solar neighbourhood". Monthly Notices of the Royal Astronomical Society. 504 (2). Oxford University Press (OUP): 2968–2982. arXiv:2103.02748. doi:10.1093/mnras/stab688. ISSN 0035-8711. Record for this source at VizieR.
  4. ^ a b c "HD 161056". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 29 October 2024.
  5. ^ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11). Pleiades Publishing Ltd: 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/s1063773706110065. ISSN 1063-7737.
  6. ^ a b Bastien, P.; Vernet, E.; Drissen, L.; Menard, F.; Moffat, A. F. J.; Robert, C.; St-Louis, N. (April 2007). Sterken, C. (ed.). The variability of polarized standard stars. The Future of Photometric, Spectrophotometric and Polarimetric Standardization. ASP Conference Series. Vol. 364. Astronomical Society of the Pacific. p. 529. Bibcode:2007ASPC..364..529B.
  7. ^ Wiktorowicz, Sloane J.; Słowikowska, Agnieszka; Nofi, Larissa A.; Rider, Nicole; Wolfgang, Angie; Hermis, Ninos; Jontof-Hutter, Daniel; Bayless, Amanda J.; Cole, Gary M.; Crawford, Kirk B.; Tsarev, Valeri V.; Owens, Michael C.; Jaramillo, Ernest G.; Maul, Geoffrey A.; Graham, James R.; Millar-Blanchaer, Maxwell A.; Bott, Kimberly; Mauerhan, Jon C. (1 February 2023). "A Decade of Linear and Circular Polarimetry with the POLISH2 Polarimeter". The Astrophysical Journal Supplement Series. 264 (2). American Astronomical Society: 42. arXiv:2211.09279. Bibcode:2023ApJS..264...42W. doi:10.3847/1538-4365/aca407. ISSN 0067-0049.
  8. ^ Yi, Shitong (April 1981). 中西对照恒星图表 [Atlas Comparing Chinese and Western Star Maps and Catalogues] (in Chinese). 科学出版社.
  9. ^ Bastien, P.; Drissen, L.; Menard, F.; Moffat, A. F. J.; Robert, C.; St-Louis, N. (1988). "The variability of polarized standard stars". The Astronomical Journal. 95. American Astronomical Society: 900. Bibcode:1988AJ.....95..900B. doi:10.1086/114688. ISSN 0004-6256.
  10. ^ Somerville, W. B.; Allen, R. G.; Carnochan, D. J.; He, Lida; McNally, D.; Martin, P. G.; Morgan, D. H.; Nandy, K.; Walsh, J. R.; Whittet, D. C. B.; Wilson, R.; Wolff, M. J. (1994). "Ultraviolet interstellar polarization observed with the Hubble Space Telescope". The Astrophysical Journal. 427. American Astronomical Society: L47. Bibcode:1994ApJ...427L..47S. doi:10.1086/187361. ISSN 0004-637X.
  11. ^ Mathis, John S. (1990). "Interstellar Dust and Extinction". Annual Review of Astronomy and Astrophysics. 28 (1). Annual Reviews: 37–70. Bibcode:1990ARA&A..28...37M. doi:10.1146/annurev.aa.28.090190.000345. ISSN 0066-4146.
  12. ^ Papoular, Renaud (12 June 2018). "A new interpretation of Serkowski's polarization law". Monthly Notices of the Royal Astronomical Society. 479 (2). Oxford University Press (OUP): 1685–1693. arXiv:1806.03001. doi:10.1093/mnras/sty1530. ISSN 0035-8711.
  13. ^ Fan, Haoyu; Rocha, Carlos M. R.; Cordiner, Martin; Linnartz, Harold; Cox, Nick L. J.; Farhang, Amin; Smoker, Jonathan; Roueff, Evelyne; Ehrenfreund, Pascale; Salama, Farid; Foing, Bernard H.; Lallement, Rosine; MacIsaac, Heather; Kulik, Klay; Sarre, Peter; van Loon, Jacco Th.; Cami, Jan (22 December 2023). "The EDIBLES survey". Astronomy & Astrophysics. 681. EDP Sciences: A6. arXiv:2310.03259. doi:10.1051/0004-6361/202243910. ISSN 0004-6361.
  14. ^ Cox, N. L. J.; Cami, J.; Kaper, L.; Ehrenfreund, P.; Foing, B. H.; Ochsendorf, B. B.; van Hooff, S. H. M.; Salama, F. (2014). "VLT/X-Shooter survey of near-infrared diffuse interstellar bands". Astronomy & Astrophysics. 569. EDP Sciences: A117. arXiv:1407.0370. Bibcode:2014A&A...569A.117C. doi:10.1051/0004-6361/201323061. ISSN 0004-6361.
  15. ^ Peri, C. S.; Benaglia, P.; Isequilla, N. L. (2015). "E-BOSS: An Extensive stellar BOw Shock Survey". Astronomy & Astrophysics. 578. EDP Sciences: A45. arXiv:1504.04264. doi:10.1051/0004-6361/201424676. ISSN 0004-6361.
  16. ^ Hoogerwerf, R.; de Bruijne, J. H. J.; de Zeeuw, P. T. (1 December 2000). "The Origin of Runaway Stars". The Astrophysical Journal. 544 (2). American Astronomical Society: L133–L136. arXiv:astro-ph/0007436. Bibcode:2000ApJ...544L.133H. doi:10.1086/317315. ISSN 0004-637X.
  17. ^ Bobylev, V. V. (29 September 2008). "Open clusters IC 4665 and Cr 359 and a probable birthplace of the pulsar PSR B1929+10". Astronomy Letters. 34 (10). Pleiades Publishing Ltd: 686–698. arXiv:0810.0217. Bibcode:2008AstL...34..686B. doi:10.1134/s1063773708100046. ISSN 1063-7737.
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