Jabbah

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Double star
Jabbah
Observation
dates equinox :  J2000.0 , epoch : J2000.0
AladinLite
Constellation Scorpio
Apparent brightness  approx. 3.9 mag
Astrometry
Radial velocity −2.4 ± 5 ​​km / s
parallax 7.10 ± 0.41 mas
distance  460 ± 30 ly
(141 ± 9 pc )
Proper movement :
Rec. Share: −7.65 ± 0.71 mas / a
Dec. portion: −23.71 ± 0.47 mas / a
orbit 
period approx. 70,000 a
Individual data
Names FROM; CD
Observation data:
Right ascension FROM 16 h 11 m 59.74 s
CD 16 h 11 m 58.59 s
declination FROM 1807262.4−19 ° 27 ′ 37.6 ″
CD 1807299.9−19 ° 27 ′ 00.1 ″
Apparent brightness FROM 4.01 likes
CD 6.30 mag
Typing:
Spectral class FROM B3 V
CD B8 V + B9 VpSi
B − V color index FROM 0.04
CD 0.13
U − B color index FROM −0.65
CD −0.37
Physical Properties:
Dimensions FROM System: approx. 26 M ☉
CD System: approx. 10 M ☉
Luminosity FROM Aa: 4,930 L ☉
CD
Effective temperature FROM Aa: 21,150 K
CD
Other names
and catalog entries
Bayer name ν Scorpii
Flamsteed name 14 Scorpii
Bonn survey BD −19 ° 4333 BD −19 ° 4332
Bright Star Catalog HR 6027 HR 6026
Henry Draper Catalog HD 145502 HD 145501
SAO catalog SAO 159764 SAO 159763
Tycho catalog TYC 6209-1537-1 [1] TYC 6209-1536-1 [2]
Hipparcos catalog HIP 79374 HIP -
WDS catalog WDS 16120-1928

Template: Infobox double star / maintenance / single coordinates

Jabbah ( Arabic الجبهة, DMG al-ǧabha  'forehead'), Bayer name ν Scorpii ( Ny Scorpii , short ν Sco), is a fourth magnitude star in the constellation Scorpio . It is a multiple star system approx. 460 light years away , which is composed of six or seven stars.

The Jabbah system is a member of the Scorpius-Centaurus Association and associated with the reflection nebula IC 4592.

Structure and physical properties

The Jabbah system (schematic, not to scale).

Jabbah is at least a physical six-fold system, probably even a seven-fold system. This is quite remarkable, because although we know numerous multiple systems with four or five components as well as some six-fold systems (e.g. Castor , Akrab , possibly Mizar  -  Alkor ), besides Jabbah only AR Cassiopeiae in the constellation Cassiopeia is known as a seven-fold system.

The Jabbah system is initially divided into two subsystems: the four- fold system ν Scorpii A and B (HR 6027, HD 145502) and the double or triple system ν Scorpii C and D (HR 6026, HD 145501). ν Scorpii AB and ν Scorpii CD form the main system with a mutual orbital period of approximately 70,000 years. The angular distance between the systems is 41.1 ″, the position angle of the CD system with respect to the AB system is 337 °. The apparent brightnesses are 4.0 m for ν Scorpii AB and 6.3 m for ν Scorpii CD .

ν Scorpii A and B

ν Scorpii A (HR 6027 A, HR 145502 A) and ν Scorpii B (HR 6027 B, HR 145502 B) have apparent brightnesses of 4.2 m and 6.6 m . The stars are 1.3 ″ apart, with component B having a position angle of 2 ° to component A, and orbiting each other with an orbital period of around 450 years.

ν Scorpii A belongs to the spectral and luminosity class B3 V or B2 IV. The star actually consists of three single stars - these are ν Scorpii Aa (HR 6027 Aa, HD 145502 Aa), ν Scorpii Ab (HR 6027 Ab, HD 145502 Ab) and ν Scorpii Ac (HR 6027 C, HD 145502 C). Of these, ν Scorpii Aa and Ab form a spectroscopic binary star with an orbital period of 5.55 days, but in which only the spectrum of the main star is visible (spectroscopic double star of type SB1). Mass estimates result in around eight or eleven solar masses for component Aa and at least one solar mass for component Ab. According to the spectral type, ν Scorpii Aa has an effective surface temperature of 21,000 K and 5,000 times the luminosity of the sun . The component Ac is 0.07 ″ away from Aa / Ab at a position angle of 346 ° (as of April 2010). The star, which weighs about six solar masses, orbits the pair Aa / Ab with a period of about a decade.

At ν Scorpii B the mass is estimated to be five and a half or seven and a half solar masses.

ν Scorpii C and D

The stars ν Scorpii C (HR 6026 A, HD 145501 A) and ν Scorpii D (HR 6026 B, HD 145501 B) are 6.6 m and 7.2 m bright and have an angular distance of 2.4 "(position angle of ν Scorpii D with respect to C: 56 °). The mutual orbital period is around 1,400 years.

ν Scorpii C has spectral class B8 and luminosity class V and has about four solar masses.

The component ν Scorpii D shows changes in the radial velocity . This makes a spectroscopic companion very likely, but an orbital period could not be determined from it. The possible single stars are designated as ν Scorpii Da (HR 6026 Ba, HD 145501 Ba) and ν Scorpii Db (HR 6026 Bb, HD 145501 Bb). ν Scorpii D is a star of the spectral type B9 with pronounced silicon emission lines in the spectrum and is classified as a Bp star ( see also: Pecular star ). The mass of the system (Da + Db) is estimated to be six solar masses.

observation

The main system with a distance of 41.1 ″ can be resolved as a double star with binoculars (on a tripod). In a telescope with an opening width of 6 cm or more, components C and D can be resolved into two stars with an angular distance of 2.4 ″, and components A and B with an opening of at least 10 cm can be resolved into two stars accessible four stars. However, it must be taken into account that Jabbah in Central Europe is relatively close to the horizon in the summer sky and thus seeing can make the resolution more difficult.

Using speckle interferometry or adaptive optics , professional telescopes can also separate the component Ac from Aa / Ab (distance: 0.07 ″).

Associations

The Jabbah system belongs to the Scorpius-Centaurus Association , more precisely to the Upper Scorpius subgroup. Parallax measurements at Jabbah resulted in distances of 470 ± 60 ly ( Hipparcos catalog , determined on ν Scorpii AB) and 460 ± 30 ly ( Gaia DR1 , determined on ν Scorpii C). In contrast, the average distance of the Upper Scorpius subgroup is approx. 470 ly.

Jabbah is also the illuminating star for the reflection nebula IC 4592. The nebula, measuring 140 by 80 arc minutes, appears bluish on long-exposure photographs and is also referred to as the Blue Horsehead Nebula, as its outline is reminiscent of a horse's head standing upside down (not to be confused with the Horsehead Nebula in the constellation Orion ).

Covered by the moon and planets

As a star near the ecliptic, Jabbah can be covered by the moon and very rarely by planets. Mercury last covered Jabbah on December 14, 1821 and will not re-cover Jabbah until December 2, 2031. The last occultation of Jabbah by Venus took place on December 27, 1852, the next will not take place again until December 30, 2095. On July 29, 1808, Neptune covered Jabbah.

Individual evidence

  1. ↑ a b c d e f g h Dorrit Hoffleit, Wayne H. Warren Jr .: VizieR Online Data Catalog: Bright Star Catalog, 5th Revised Ed. (Hoffleit +, 1991) . In: VizieR On-line Data Catalog: V / 50 . 1995. bibcode : 1995yCat.5050 .... 0H . Catalog entries for HR 6026 and HR 6027 on VizieR . Total brightness of HR 6026 (6.30 m ) and HR 6027 (4.01 m ) = −2.5 · lg (10 −0.4 · 4.01  + 10 −0.4 · 6.30 ) ≈ 3, 9 m .
  2. ^ DS Evans: The Revision of the General Catalog of Radial Velocities . In: Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium . No. 30, 1967. bibcode : 1967IAUS ... 30 ... 57E . Quoted from SIMBAD .
  3. ↑ a b Gaia Collaboration: VizieR Online Data Catalog: Gaia DR1 (Gaia Collaboration, 2016) . In: VizieR On-line Data Catalog: I / 337 . 2017. bibcode : 2016yCat.1337 .... 0G . Catalog entry on VizieR.
  4. ↑ Derived from parallax.
  5. ↑ a b c d e f g h i j k Andrei A. Tokovinin: VizieR Online Data Catalog: Multiple star catalog (MSC) (Tokovinin 1997-1999) . In: VizieR On-line Data Catalog: J / A + AS / 124/75 . 1999. bibcode : 1999yCat..41240075T . Catalog entry on VizieR.
  6. ↑ a b c Claus Fabricius et al. : VizieR Online Data Catalog: Tycho Double Star Catalog (TDSC) (Fabricius + 2002) . In: VizieR On-line Data Catalog: I / 276. Originally published in: 2002A & A ... 384..180F . 2001. bibcode : 2001yCat.1276 .... 0F . Catalog entry on VizieR . Note: Right ascension and declination in the info box are mean values ​​for the pairs AB and CD (the catalog gives separate coordinates for all four components).
  7. ↑ a b c d Markus M. Hohle, Ralph Neuhauser, Bernard F. Schutz: VizieR Online Data Catalog: O, B-type & red supergiant masses and luminosities (Hohle +, 2010) . In: VizieR On-line Data Catalog: J / AN / 331/349 . 2010. bibcode : 2010yCat.113310349H . Catalog entry on VizieR.
  8. ↑ Both the Multiple star catalog (Tokovinin, 1997, bibcode : 1997A & AS..124 ... 75T ) and the Catalog of multiplicity among bright stellar systems (Tokovinin, Eggleton, 2008, bibcode : 2008MNRAS.389..869E ) only list these two sevenfold systems.
  9. ↑ a b c Brian D. Mason et al. : VizieR Online Data Catalog: The Washington Visual Double Star Catalog (Mason + 2001-2014) , Version 2018-06-11. In: VizieR On-line Data Catalog: B / wds . 2018. bibcode : 2018yCat .... 102026M . Catalog entry on VizieR . Stand for distances and position angles: 2017.
  10. ^ Nancy M. Houk, M. Smith-Moore: Michigan Catalog of Two-dimensional Spectral Types for the HD Stars. Volume 4, Declinations -26 ° .0 to -12 ° .0 . In: Michigan Catalog of Two-dimensional Spectral Types for the HD Stars . Vol. 4, 1988. bibcode : 1988mcts.book ..... H . Catalog entry on VizieR.
  11. ↑ a b c d e Hugo Levato et al. : Stellar multiplicity in the Scorpius-Centaurus association . In: Astrophysical Journal Supplement Series . Vol. 64, 1987, pp. 493, 497, 500. bibcode : 1987ApJS ... 64..487L , doi: 10.1086 / 191204 .
  12. ↑ a b c d David Lafrenière et al. : An Adaptive Optics Multiplicity Census of Young Stars in Upper Scorpius . In: The Astrophysical Journal . Vol. 785, Issue 1, 2014, Article ID 47 (18pp), pp. 3, 6, 7, 10, 13. bibcode : 2014ApJ ... 785 ... 47L , doi: 10.1088 / 0004-637X / 785/1/47 .
  13. ↑ a b Mattheus BN Kouwenhoven et al. : The primordial binary population. II .. Recovering the binary population for intermediate mass stars in Scorpius OB2 . In: Astronomy & Astrophysics . Vol. 474, Ausg. 1, 2007, Online Material p 4. bibcode : 2007A & A ... 474 ... 77K , doi: 10.1051 / 0004-6361: 20077719 , arxiv : 0707.2746 .
  14. ^ J. Andersen, B. Nordström: Radial velocities of bright southern stars. I - 139 B-type HR and FK stars . In: Astronomy & Astrophysics Supplement Series . Vol. 52, 1983, p. 475. bibcode : 1983A & AS ... 52..471A .
  15. ↑ a b John Darlington Landstreet et al. : Searching for links between magnetic fields and stellar evolution: II. The evolution of magnetic fields as revealed by observations of Ap stars in open clusters and associations . In: Astronomy & Astrophysics . Vol. 470, Issue 2, 2007, Online Material p 5. bibcode : 2007A & A ... 470..685L , doi: 10.1051 / 0004-6361: 20077343 , arxiv : 0706.0330 .
  16. ↑ Harold McAlister, William I. Hartkopf, Otto G. Franz: ICCD speckle observations of binary stars. V - Measurements during 1988-1989 from the Kitt Peak and the Cerro Tololo 4 M telescopes . In: The Astronomical Journal . Vol. 99, 1990, pp. 965, 966. bibcode : 1990AJ ..... 99..965M , doi: 10.1086 / 115387 .
  17. ^ Floor van Leeuwen: VizieR Online Data Catalog: Hipparcos, the New Reduction (van Leeuwen, 2007) . In: VizieR On-line Data Catalog: I / 311 . 2008. bibcode : 2008yCat.1311 .... 0V . Catalog entry on VizieR.
  18. ↑ Tim de Zeeuw et al. : A HIPPARCOS Census of the Nearby OB Associations . In: The Astronomical Journal . Bd. 117, Ausg. 1, 1999, p. 364. bibcode : 1999AJ .... 117..354D , doi: 10.1086 / 300682 , arxiv : astro-ph / 9809227 .
  19. ↑ Mariangela de Oliveira, Walter J. Maciel: Photoelectric photometry of CED 128 - a reflection nebula . In: Revista Mexicana de Astronomia y Astrofisica . Vol. 12, 1986, p. 273. bibcode : 1986RMxAA..12..273D .
  20. ^ Johann Dorschner, Joachim Gürtler: Investigations into reflection nebulae at the Palomar Sky Survey I. Directory of reflection nebulae . In: Astronomical News . Vol. 287, 1963, p. 259. bibcode : 1963AN .... 287..257D . doi: 10.1002 / asna.19632870507 .