Iota Serpentis

Star in the constellation Serpens

Iota Serpentis
Observation data Epoch J2000 Equinox J2000
Location of ι Serpentis (circled)
Constellation	Serpens
Right ascension	15^h 41^m 33.05469^s^[1]
Declination	19° 40′ 13.4380″^[1]
Apparent magnitude (V)	4.51^[2]
Characteristics
Evolutionary stage	main sequence
Spectral type	B9V + A1V^[3]
B−V color index	+0.062±0.003^[2]
Astrometry

Radial velocity (R_v)	−17.20^[4] km/s
Proper motion (μ)	RA: -60.86^[1] mas/yr Dec.: -43.69^[1] mas/yr
Parallax (π)	17.16 ± 0.67 mas^[1]
Distance	190 ± 7 ly (58 ± 2 pc)
Absolute magnitude (M_V)	+0.69^[2]

Orbit^[5]
Period (P)	8015.0±6.3 d
Semi-major axis (a)	0.21033±0.00047″
Eccentricity (e)	0.0941±0.0028
Inclination (i)	83.608±0.043°
Longitude of the node (Ω)	69.684±0.033°
Periastron epoch (T)	54,180±33 HMJD
Argument of periastron (ω) (secondary)	80.5±1.8°
Details
A
Mass	1.999^[3] `M`_☉
B
Mass	1.984^[3] `M`_☉
Other designations
ι Ser, 21 Serpentis, BD+20° 3138, GC 21102, HD 140159, HIP 76852, HR 5842, SAO 101682, ADS 9744, CCDM J15416+1940^[6]
Database references
SIMBAD	data

ι Serpentis, Latinized as Iota Serpentis and abbreviated Iot Ser, is a triple star^[7] system in the constellation Serpens, in its head (Serpens Caput). It is approximately 190 light years from Earth.^[1]

At the centre of the system is a spectroscopic binary, Iota Serpentis A and B. These are both white main sequence dwarfs and both have apparent magnitudes of +5.3. This binary has an orbital period variously reported as 11^[8] or 22^[5] years. First discovered as an astrometric binary, the pair have now been resolved and visual orbits have been derived.^[5]

There are two visual companions, Iota Serpentis C, a 13th magnitude star 143 arcseconds away and Iota Serpentis D, a 12th magnitude star 151 arcseconds distant.

References

^ ^a ^b ^c ^d ^e ^f van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600. Vizier catalog entry
^ ^a ^b ^c 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.
^ ^a ^b ^c Martin, C.; et al. (1998). "Mass determination of astrometric binaries with Hipparcos. III. New results for 28 systems". Astronomy and Astrophysics Supplement. 133 (2): 149. Bibcode:1998A&AS..133..149M. doi:10.1051/aas:1998459.
^ Evans, D. S. (June 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". In Batten, Alan Henry; Heard, John Frederick (eds.). Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. Vol. 30. University of Toronto: International Astronomical Union. p. 57. Bibcode:1967IAUS...30...57E.
^ ^a ^b ^c Muterspaugh, Matthew W.; et al. (2010). "The Phases Differential Astrometry Data Archive. II. Updated Binary Star Orbits and a Long Period Eclipsing Binary". The Astronomical Journal. 140 (6): 1623–1630. arXiv:1010.4043. Bibcode:2010AJ....140.1623M. doi:10.1088/0004-6256/140/6/1623. S2CID 6030289.
^ "iot Ser". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-09-09.
^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
^ van den Bos, W. H. (1965). "Note on the Double Star Iota Serpentis". Monthly Notes of the Astronomical Society of Southern Africa. 24: 123. Bibcode:1965MNSSA..24..123V.

Constellation of Serpens

Stars

Bayer	α (Unukalhai) β (Chow) γ (Ainalhai) δ ε ζ η θ (Alya) ι κ (Gudja) λ μ ν ξ ο π ρ σ τ¹ τ² τ³ τ⁴ τ⁵ τ⁶ τ⁷ τ⁸ υ φ χ ψ ω
Flamsteed	3 4 5 6 7 8 10 11 (A¹) 14 16 25 (A²) 29 36 (b) 39 40 43 45 46 47 59 (d) 60 (c) 61 64 3 Her 47 Oph
Variable	R W X RT UZ VV VY WX AA AN AO AP AR AU BQ CT CV CW EG FH FI FK FL FQ FR LV LW LX MR MS MT MV MY NN NO NQ NW OO OU PS QV QX QY V382 V411
HR	5665 5690 5692 5706 5711 5740 5745 5783 5796 5831 5850 5859 5861 5874 5909 5913 5931 5992 6005 6011 6014 6016 6449 6496 6544 6562 6568 6600 6620 6666 6681 6755 6756 6757 6785 6830 6840 6843 6858 6890 6898 6928 6993 (e) 6999 7008 7048 7076 7144
HD	135061 135615 136027 136118 138085 142245 143436 145936 146740 157969 168112 168443 168746 (Alasia) 175541 (Kaveh)
Other	ADS 9544 AS 296 9 11 22 23 27 Gliese 701 Gliese 710 GJ 1224 GX 17+2 IRAS 18418-0440 MWC 297 MWC 922 PG 1510+234 PG 1605+072 PSR B1534+11 PSR J1719−1438 Ross 508 Serpens FIRS 1 Serpens SVS 20 Serpens X-1 W40 IRS 1A South

Exoplanets	CoRoT-9b CoRoT-11b CoRoT-22b CoRoT-23b CoRoT-27b HD 168746 b (Onasilos) HD 175541 b (Kavian) ω Serpentis b

Star
clusters

NGC	NGC 6535 NGC 6539 NGC 6604 NGC 6605
Other	IC 4756 Messier 5 Messier 16 Serpens OB2 Serpens South Palomar 5

Nebulae

Other	Abell 41 Eagle Nebula L134 L183 L483 Serpens cloud Sh2-54 Westerhout 40 Red Square Nebula S68

Galaxies

NGC	5887 5910 5911 5913 5919 5920 5921 5926 5928 5931 5936 5937 5940 5942 5941 5944 5951 5953 5954 5952 5956 5955 5957 5960 5962 5964 5970 5972 5975 5977 5980 5983 5984 5988 5991 5990 5994 5996 5997 6003 6004 6008 6006 6007 6009 6012 6010 6014 6020 6017 6018 6021 6022 6023 6027 6027a 6027b 6027c 6027d 6027e 6029 6033 6037 6036 6051 6063 6065 6066 6070 6080 6100 6118 6172
Other	317 318 321 323.1 324 326 Arp 72 Arp 220 4C 11.50 CGCG 049-033 Hoag's Object IC 4537 IC 4588 IRAS 15107+0724 NRAO 530 PDS 456 PG 1553+113 PGC 54493 PKS 1546+027

NGC