Qatar-2

Star in the constellation Virgo

Qatar-2  Observation data
Epoch J2000 Equinox J2000

Constellation | Virgo[1]
Right ascension | 13h 50m 37.4100s[2]
Declination | −06° 48′ 14.422″[2]
Apparent magnitude (V) | 13.3[3]
Characteristics
Spectral type | K5V[4]
Astrometry
Radial velocity (Rv)| −23.55[5] km/s
Proper motion (μ)|  RA: −88.171[2] mas/yr
Dec.: −15.187[2] mas/yr
Parallax (π)| 5.4023±0.0195 mas[2]
Distance| 604 ± 2 ly
(185.1 ± 0.7 pc)
Details[6][3]
Mass| 0.727±0.024 M☉
Radius| 0.7033±0.0080 R☉
Surface gravity (log g)| 4.601±0.018 cgs
Temperature| 4,645±50 K
Metallicity [Fe/H]| 0.13±0.1[7] dex
Rotation| 18.0±0.2
Rotational velocity (v sin i)| 2.0±0.2 km/s
Age| 9 Gyr
Other designations
Gaia DR2 3620030644476623616, GSC 04974-00112, 2MASS J13503740-0648145[8]
Database references
SIMBAD| data

Qatar-2 is a K-type main-sequence star about 595 light-years away in the constellation of Virgo. The star is much older than Sun, and has a concentration of heavy elements similar to solar abundance.[3] The star features a numerous and long-lived starspots,[6] and belongs to a peculiar variety of inflated K-dwarfs with strong magnetic activity inhibiting internal convection.[9]

## Planetary system

[edit]

In 2011 a transiting superjovian planet Qatar-2b was detected by the Qatar Exoplanet Survey.[3] The planet has a large measured temperature difference between dayside 1,368±32 K and nightside 724±135 K.[10] The planetary orbit is well aligned with the equatorial plane of the star,[7] misalignment angle equal to 4.3°±4.5°.[11] No orbital decay was detected.[12] The color of planetary atmosphere is blue due to Rayleigh scattering of light,[11] and albedo is very low, being below 0.06.[12]

An additional massive companion on wide orbit was suspected in 2011,[3] but search utilizing transit-timing variation method has yielded zero results in 2017.[6]

The Qatar-2 planetary system[3][6] Companion
(in order from star) | Mass | Semimajor axis
(AU) | Orbital period
(days) | Eccentricity | Inclination | Radius

|
|
|
|
|
|

b | 2.466±0.062 MJ | 0.02136±0.00024  | 1.33711677±0.00000010  | 0  | 88.99±0.20° | 1.115±0.013 RJ

## References

[edit]

1. ^ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object at VizieR.
2. ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
3. ^ a b c d e f Bryan, Marta L.; Alsubai, Khalid A.; Latham, David W.; Parley, Neil R.; Collier Cameron, Andrew; Quinn, Samuel N.; Carter, Joshua A.; Fulton, Benjamin J.; Berlind, Perry; Brown, Warren R.; Buchhave, Lars A.; Calkins, Michael L.; Esquerdo, Gilbert A.; Fűrész, Gábor; Jørgensen, Uffe Gråe; Horne, Keith D.; Stefanik, Robert P.; Street, Rachel A.; Torres, Guillermo; West, Richard G.; Dominik, Martin; Harpsøe, Kennet B. W.; Liebig, Christine; Calchi Novati, Sebastiano; Ricci, Davide; Skottfelt, Jesper F. (2011), "Qatar-2: A K dwarf orbited by a transiting hot Jupiter and a more massive companion in an outer orbit", The Astrophysical Journal, 750: 84, arXiv:1110.5912, doi:10.1088/0004-637X/750/1/84, S2CID 118627543
4. ^ Dressing, Courtney D.; Newton, Elisabeth R.; Schlieder, Joshua E.; Charbonneau, David; Knutson, Heather A.; Vanderburg, Andrew; Sinukoff, Evan (2017). "Characterizing K2 Candidate Planetary Systems Orbiting Low-mass Stars. I. Classifying Low-mass Host Stars Observed during Campaigns 1-7". The Astrophysical Journal. 836 (2): 167. arXiv:1701.00586. Bibcode:2017ApJ...836..167D. doi:10.3847/1538-4357/836/2/167.
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.
6. ^ a b c d Močnik, T.; Southworth, J.; Hellier, C. (2017), "Recurring sets of recurring starspot occultations on exoplanet-host Qatar-2", Monthly Notices of the Royal Astronomical Society, 471 (1): 394–403, arXiv:1608.07524, Bibcode:2017MNRAS.471..394M, doi:10.1093/mnras/stx1557, S2CID 119240651
7. ^ a b Esposito, M.; Covino, E.; Desidera, S.; Mancini, L.; Nascimbeni, V.; Zanmar Sanchez, R.; Biazzo, K.; Lanza, A. F.; Leto, G.; Southworth, J.; Bonomo, A. S.; Suárez Mascareño, A.; Boccato, C.; Cosentino, R.; Claudi, R. U.; Gratton, R.; Maggio, A.; Micela, G.; Molinari, E.; Pagano, I.; Piotto, G.; Poretti, E.; Smareglia, R.; Sozzetti, A.; Affer, L.; Anderson, D. R.; Andreuzzi, G.; Benatti, S.; Bignamini, A.; et al. (2017), "The GAPS Programme with HARPS-N at TNG. XIII. The orbital obliquity of three close-in massive planets hosted by dwarf K-type stars: WASP-43, HAT-P-20 and Qatar-2", Astronomy & Astrophysics, 601: A53, arXiv:1702.03136, Bibcode:2017A&A...601A..53E, doi:10.1051/0004-6361/201629720, S2CID 119341241
8. ^ "Qatar 2". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2025-05-05.
9. ^ Maxted, P. F. L.; Serenelli, A. M.; Southworth, J. (2015), "A comparison of gyrochronological and isochronal age estimates for transiting exoplanet host stars", Astronomy & Astrophysics, 577: A90, arXiv:1503.09111, Bibcode:2015A&A...577A..90M, doi:10.1051/0004-6361/201525774, S2CID 53324330
10. ^ May, E. M.; Stevenson, K. B.; Bean, Jacob L.; Bell, Taylor J.; Cowan, Nicolas B.; Dang, Lisa; Desert, Jean-Michel; Fortney, Jonathan J.; Keating, Dylan; Kempton, Eliza M.-R.; Komacek, Thaddeus D.; Lewis, Nikole K.; Mansfield, Megan; Morley, Caroline; Parmentier, Vivien; Rauscher, Emily; Swain, Mark R.; Zellem, Robert T.; Showman, Adam (2022), "A New Analysis of Eight Spitzer Phase Curves and Hot Jupiter Population Trends: Qatar-1b, Qatar-2b, WASP-52b, WASP-34b, and WASP-140b", The Astronomical Journal, 163 (6): 256, arXiv:2203.15059, Bibcode:2022AJ....163..256M, doi:10.3847/1538-3881/ac6261, S2CID 247778438
11. ^ a b Mancini, L.; Southworth, J.; Ciceri, S.; Tregloan-Reed, J.; Crossfield, I.; Nikolov, N.; Bruni, I.; Zambelli, R.; Henning, Th. (2014), "Physical properties, starspot activity, orbital obliquity, and transmission spectrum of the Qatar-2 planetary system from multi-colour photometry", Monthly Notices of the Royal Astronomical Society, 443 (3): 2391, arXiv:1406.6714, Bibcode:2014MNRAS.443.2391M, doi:10.1093/mnras/stu1286, S2CID 119203713
12. ^ a b Dai, Fei; Winn, Joshua N.; Yu, Liang; Albrecht, Simon (2016), "The Stellar Obliquity, Planet Mass, and Very Low Albedo of Qatar-2 from K2 Photometry", The Astronomical Journal, 153: 40, arXiv:1609.01314, doi:10.3847/1538-3881/153/1/40, S2CID 56019135

* v
* t
* e

Constellation of Virgo

* List of stars in Virgo

Stars|

| Bayer|

* α (Spica)
* β (Zavijava)
* γ (Porrima)
* δ (Minelauva)
* ε (Vindemiatrix)
* ζ (Heze)
* η (Zaniah)
* θ
* ι (Syrma)
* κ (Kang)
* λ (Khambalia)
* μ
* ν
* ξ
* ο
* π
* ρ
* σ
* τ
* υ
* φ (Elgafar)
* χ
* ψ
* ω

|

Flamsteed|

* 4 (A1)
* 6 (A2)
* 7 (b)
* 10
* 11
* 12
* 13
* 14
* 16 (c)
* 17
* 20
* 21 (q)
* 25 (f)
* 27
* 28
* 31 (d1)
* 32 (d2)
* 33
* 34
* 35
* 37
* 38
* 39
* 41
* 44 (k)
* 46
* 48
* 49
* 50
* 53
* 54
* 55
* 56
* 57
* 58
* 59 (e)
* 61
* 62
* 63
* 64
* 65
* 66
* 68 (i)
* 69
* 70
* 71
* 72
* 73
* 74 (l)
* 75
* 76 (h)
* 77
* 78 (o)
* 80
* 81
* 82 (m)
* 83
* 84
* 85
* 86
* 87
* 88
* 89
* 90 (p)
* 92
* 94
* 95
* 96
* 97
* 103
* 104
* 106
* 108
* 109
* 110
* 1 Ser (M Ser)
* 2 Ser

Variable|

* R
* S
* W
* RT
* SS
* SW
* AG
* AH
* BH
* CS
* CU
* EQ
* ET
* FG
* GL
* GW
* HW
* NY
* QS

HR|

* 4587
* 5183
* 5384

HD|

* 102195 (Flegetonte)
* 106252
* 106315
* 106515
* 107148
* 109271
* 114783
* 125612
* 126614
* 130322 (Mönch)
* 133600

Other|

* Gliese 486 (Gar)
* Gliese 514
* HAT-P-26 (Guahayona)
* HAT-P-27
* HE 1219−0312
* K2-19
* K2-229
* PSR B1257+12 (Lich)
* PSR J1748−2021B
* Qatar-2
* Ross 128
* Ross 458
* SDSS J1229+1122
* ULAS J133553.45+113005.2
* WASP-16
* WASP-24
* WASP-37
* WASP-39 (Malmok)
* WASP-54
* WASP-55
* WD 1145+017
* Wolf 424
* Wolf 489

| Exoplanets|

* 38 Virginis b
* 61 Virginis b
* c
* 70 Virginis b
* Gliese 504 b
* Gliese 536 b
* HD 102195 b (Lete)
* HD 106252 b
* HD 107148 b
* HD 114783 b
* HD 125612 b
* c
* d
* HD 126614 Ab
* HD 130322 b (Eiger)
* HR 5183 b
* K2-137b
* K2-229b
* KELT-21b
* PSR B1257+12 A (Draugr)
* B (Poltergeist)
* C (Phobetor)
* Ross 128 b
* WASP-16b
* WASP-24b
* WASP-39b (Bocaprins)
* WASP-85 Ab
* WASP-107b
* WD 1145+017 b

|

| Star clusters|

* HVGC-1
* Koposov 1
* NGC 5634

|

| Nebulae|

* Abell 36

|

Galaxies|

| Messier|

* 49
* 58
* 59
* 60
* 61
* 84
* 86
* 87
* 89
* 90
* 104 (Sombrero Galaxy)

|

NGC|

* 3776
* 3817
* 3818
* 3833
* 3843
* 3848
* 3852
* 3914
* 3915
* 4030
* 4123
* 4129
* 4178
* 4179
* 4197
* 4200
* 4206
* 4207
* 4216
* 4246
* 4252
* 4260
* 4261
* 4267
* 4273
* 4294
* 4296
* 4297
* 4299
* 4301
* 4305
* 4306
* 4307
* 4309
* 4313
* 4316
* 4318
* 4320
* 4324
* 4325
* 4326
* 4330
* 4333
* 4343
* 4365
* 4368
* 4380
* 4388
* 4402
* 4420
* 4424
* 4429
* 4436
* 4440
* 4451
* 4452
* 4454
* 4457
* 4458
* 4461
* 4464
* 4466
* 4467
* 4469
* 4470
* 4476
* 4478
* 4482
* 4483
* 4487
* 4488
* 4491
* 4492
* 4496
* 4497
* 4503
* 4504
* 4517
* 4519
* 4522
* 4526
* 4527
* 4528
* 4531
* 4535
* 4536
* 4544
* 4546
* 4550
* 4551
* 4564
* 4567
* 4568
* 4570
* 4578
* 4580
* 4586
* 4593
* 4596
* 4598
* 4606
* 4607
* 4608
* 4612
* 4620
* 4623
* 4630
* 4632
* 4636
* 4637
* 4638
* 4639
* 4643
* 4647 (Arp 116)
* 4654
* 4658
* 4660
* 4664
* 4666
* 4674
* 4680
* 4691
* 4694
* 4697
* 4698
* 4699
* 4700
* 4701
* 4713
* 4731
* 4733
* 4734
* 4746
* 4753
* 4754
* 4762
* 4772
* 4775
* 4777
* 4780
* 4781
* 4790
* 4818
* 4825
* 4845
* 4856
* 4866
* 4900
* 4902
* 4918
* 4939
* 4941
* 4958
* 4984
* 4991
* 4995
* 4999
* 5006
* 5010
* 5018
* 5030
* 5050
* 5054
* 5068
* 5084
* 5087
* 5170
* 5174
* 5177
* 5235
* 5247
* 5252
* 5300
* 5331
* 5334
* 5335
* 5343
* 5363
* 5364
* 5384
* 5468
* 5470
* 5501
* 5506
* 5555
* 5566
* 5575
* 5584
* 5619
* 5668
* 5679
* 5701
* 5705
* 5713
* 5719
* 5746
* 5750
* 5765
* 5774
* 5775
* 5806
* 5838
* 5846
* 5850

Other|

* A1689-zD1
* Abell 1835 IR1916
* Arp 240 (NGC 5257 and NGC 5258)
* Arp 271 (NGC 5426 and NGC 5427)
* 3C 273
* 3C 279
* 4C 03.24
* Eyes Galaxies
* GR 8
* Hedgehog
* IC 1011
* IC 1101
* IC 3078
* IC 3430
* IC 3583
* IRAS 12112+0305
* LEDA 1245565
* M60-UCD1
* PKS 1148−001
* PKS 1302−102
* PKS 1335−127
* PKS 1402+044

| Galaxy clusters|

* Abell 1689
* Abell 1835
* Abell 2029
* Abell 2147
* IRAS 13218+0552
* RX J1347.5−1145
* Virgo Cluster

|

| Astronomical events|

* North Polar Spur
* SN 1990N
* SN 1994D
* SN 2002cx
* SN 2007bi
* SN 2020jfo
* U1.11

|

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