2 Lyncis

Binary star in the constellation Lynx

2 Lyncis
Observation data Epoch J2000 Equinox J2000
2 Lyncis in optical light.
Constellation	Lynx
Right ascension	06^h 19^m 37.38458^s^[1]
Declination	+59° 00′ 39.4683″^[1]
Apparent magnitude (V)	4.44^[2]
Characteristics
Spectral type	A2 Vs^[3]
B−V color index	0.032±0.004^[2]
Variable type	Eclipsing binary^[4]
Astrometry

Radial velocity (R_v)	−2.0±0.1^[5] km/s
Proper motion (μ)	RA: −5.35^[1] mas/yr Dec.: +23.86^[1] mas/yr
Parallax (π)	20.83 ± 0.40 mas^[1]
Distance	157 ± 3 ly (48.0 ± 0.9 pc)
Absolute magnitude (M_V)	1.03^[2]

Orbit^[6]
Period (P)	1306.82±0.96 d
Eccentricity (e)	0.497±0.010
Periastron epoch (T)	2450962.0±2.0
Argument of periastron (ω) (secondary)	186.30±0.79°
Semi-amplitude (K₁) (primary)	3.281±0.044 km/s
Details^[6]
2 Lyn A
Mass	2.32±0.02^[3] `M`_☉
Radius	2.2 `R`_☉
Luminosity	39.5+1.8 −1.7^[3] `L`_☉
Surface gravity (log g)	4.1±0.1 cgs
Temperature	9,310±100 K
Rotation	1.56 d
Rotational velocity (v sin i)	44 km/s
2 Lyn B
Mass	0.46 `M`_☉
Other designations
2 Lyn, UZ Lyn, BD+59° 959, FK5 237, HD 43378, HIP 30060, HR 2238, SAO 25665^[7]
Database references
SIMBAD	data

2 Lyncis is a binary star system in the northern constellation Lynx. It is visible to the naked eye, having an apparent visual magnitude of 4.44.^[2] The distance to this system, judging by an annual parallax shift of 20.83±0.40 mas,^[1] is around 157 light years. It is moving closer to the Sun with a heliocentric radial velocity of −2 km/s.^[5]

This is a spectroscopic binary star system with an orbital period of around 3.6 years and an eccentricity of 0.5. It is classified as a probable (91% chance) eclipsing binary with the variable star designation UZ Lyn, showing a net magnitude decrease of 0.3 during an occultation.^[4]

The primary component is an A-type main-sequence star^[6] with a stellar classification of A2 Vs,^[3] where the 's' indicates narrow (sharp) absorption lines. The orbiting companion may be the source of the X-ray emission from this system, as stars similar to the primary component do not generally produce detectable levels of X-rays.^[8]

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.
^ ^a ^b ^c ^d 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 ^d Zorec, J.; Royer, F. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691, S2CID 55586789.
^ ^a ^b Avvakumova, E. A.; et al. (October 2013), "Eclipsing variables: Catalogue and classification" (PDF), Astronomische Nachrichten, 334 (8): 860, Bibcode:2013AN....334..860A, doi:10.1002/asna.201311942, hdl:10995/27061
^ ^a ^b de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
^ ^a ^b ^c Lehmann, H.; et al. (April 2003), "Binary nature and elemental abundances of 2 Lyn and HD 169981", Astronomy and Astrophysics, 402: 229–235, Bibcode:2003A&A...402..229L, doi:10.1051/0004-6361:20030253.
^ "2 Lyn". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-03-07.
^ De Rosa, R. J.; et al. (July 2011), "The Volume-limited A-Star (VAST) survey - I. Companions and the unexpected X-ray detection of B6-A7 stars", Monthly Notices of the Royal Astronomical Society, 415 (1): 854–866, arXiv:1103.4363, Bibcode:2011MNRAS.415..854D, doi:10.1111/j.1365-2966.2011.18765.x, S2CID 84181878.

Constellation of Lynx

Stars

Bayer	α ψ¹⁰ Aur (16)
Flamsteed	1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 (Alsciaukat) 32 33 34 35 36 38 42 43 44 Cam 45 Cam 46 Cam 48 Cam 50 Cam 52 Cam 54 Cam 5 LMi 10 UMa 19 UMa
Variable	R T U Y RR SW SZ TT TV TZ UU UV UX UY AN BE BF BH BK CC CY DD DI DU
HR	2463 2486 2561 2642 2645 2721 2737 2751 2776 2804 2844 2894 2903 2914 2915 2935 2939 3028 3039 3094 3106 3130 3175 3181 3200 3246 3258 3277 3287 3292 3309 3348 3351 3360 3509 3511 3545 3546 3580 3586 3612 3625 3686 3701 3809
HD	44061 52859 58681 59721 59826 63588 63630 65392 67539 75898 (Stribor)
Other	GD 98 Gliese 277 GJ 1105 GJ 3421 HS 0702+6043 IRC +60169 J0815+4729 PG 0859+415 WASP-13 (Gloas) XO-2 XO-4 (Koit) XO-5 (Absolutno)

Exoplanets	6 Lyncis b WASP-13b (Cruinlagh) XO-2Nb XO-4b (Hämarik) XO-5b (Makropulos)

Star clusters	NGC 2666

Nebulae	Jones-Emberson 1 Lynx Arc

Galaxies

NGC	2273 2273B 2308 2315 2320 2321 2322 2326 2326A 2329 2330 2332 2337 2340 2344 2415 2424 2426 2429 2429A 2429B 2431 2444 2445 2446 2456 2457 2458 2461 2462 2463 2468 2469 2472 2473 2474 2475 2476 2484 2488 2493 2495 2497 2500 2505 2518 2519 2521 2524 2528 2532 2534 2537 2537A 2541 2543 2549 2552 2638 2649 2668 2683 2691 2704 2712 2719 2719A 2724 2746 2755 2759 2770 2776 2778 2779 2780 2782 2785 2793 2798 2799 2823 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2838 2839 2840 2844 2852 2853 2860
Other	3C 171 APM 08279+5255 SDSS J082535.19+512706.3 IC 2233 IRAS 09104+4109 UGC 4653 UGC 4881 UGC 4904

NGC