Astronomy:HD 135344

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Short description: Young star system in the constellation of Lupus
HD 135344
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The orbit of HD 135344 Ab around HD 135344 A (blocked by a coronagraph)
Credit: Stolker et al
Observation data
{{#ifeq:J2000|J2000.0 (ICRS)|Epoch J2000.0      Equinox J2000.0 (ICRS)| [[History:Epoch|Epoch J2000]]      [[Astronomy:Equinox (celestial coordinates)|Equinox J2000}}
Constellation Lupus[1]
A
Right ascension  15h 15m 48.9463s[2]
Declination −37° 08′ 55.731″[2]
Apparent magnitude (V) 7.76[3]
B
Right ascension  15h 15m 48.4460s[4]
Declination −37° 09′ 16.024″[4]
Apparent magnitude (V) 8.708[5]
Characteristics
A
Evolutionary stage main sequence[6]
Spectral type A0V[3]
B
Evolutionary stage main sequence[4]
Spectral type F8V[5]
Astrometry
A
Radial velocity (Rv)29.31±3.29[2] km/s
Proper motion (μ) RA: −18.738[2] mas/yr
Dec.: −24.008[2] mas/yr
Parallax (π)7.4105 ± 0.0403[2] mas
Distance440 ± 2 ly
(134.9 ± 0.7 pc)
B
Radial velocity (Rv)−5.34±1.48[4] km/s
Proper motion (μ) RA: −19.210 mas/yr
Dec.: −23.268 mas/yr
Parallax (π)7.4074 ± 0.0240[4] mas
Distance440 ± 1 ly
(135.0 ± 0.4 pc)
Details
A
Mass2.32[7] M
Radius1.50±0.01[6] R
Luminosity16.6±0.4[6] L
Surface gravity (log g)4.1±0.1[6] cgs
Temperature9540±100[6] K
Metallicity [Fe/H]0.10[8] dex
B
Mass1.5[4] M
Radius2.1[4] R
Luminosity6.4[4] L
Surface gravity (log g)3.80[4] cgs
Temperature6,313[4] K
Age10.5[9] Myr
Other designations
CD−36 10010, HD 135344[3]
A: CPD−36 6758, SAO 206463, TYC 7324-1671-1[3]
B: CPD−36 6759, SAO 206462, TYC 7324-1676-1[5]
Database references
SIMBADA
B

HD 135344 is a young binary star system about 440 light-years away from Earth in the constellation Lupus. The primary star hosts a directly imaged gas giant planet, while the secondary star, also known as SAO 206462, is surrounded by a circumstellar disk of gas with clearly defined spiral arms and has three planet candidates.

HD 135344 A

HD 135344 A is an A-type main-sequence star. It hosts a directly imaged gas giant planet, about 10 times the mass of Jupiter, discovered in 2025 with VLT/SPHERE.[6]

The HD 135344 A planetary system[6]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(years)
Eccentricity Inclination Radius
b 10.0+1.4
−1.9
 MJ
16.5+2.8
−2.0
0.5±0.2 73.6+2.8
−4.7
°
1.45+0.06
−0.03
 – 1.60+0.07
−0.06
 RJ

HD 135344 B

The disk around HD 135344B (SAO 206462) imaged by VLT/SPHERE

HD 135344 B, also known as SAO 206462, has been known to have a circumstellar disk since the 1990s, first detected based on an infrared excess.[10] Observations of the structure of the disk were presented in July 2009 by Carol Grady, astronomer of Eureka Scientific, headquartered in the Goddard Space Flight Center at NASA. It was the first of this class that exhibited a high degree of clarity and was observed using several space telescopes (Hubble, FUSE, Spitzer) and ground-based telescopes (Gemini Observatory and Subaru Telescope, situated in Hawaii), through an international research program of young stars and of stars with planets. A number of astronomers of different observatories collaborated.[11] The disk's diameter is about twice the size of the orbit of Pluto.[12]

Evidence of planets

The protoplanetary disk of HD 135344B as seen by the ERIS instrument of the VLT with the position of a potential forming exoplanet indicated
The HD 135344 B (SAO 206462) planetary system
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(years)
Eccentricity Inclination Radius
b (unconfirmed) 2[13] MJ 28[13] 2[13] RJ
(unconfirmed) 66±3[14] 424±25[14]
CC1 (unconfirmed) 0.8±0.3[15] MJ 300.8+9.9
−9.5
[15]

The pair of spiral arms around SAO 206462 have a rotation rate of −0.85 degrees per year, which are thought to be caused by a dynamically driving protoplanet within the disk, at a distance of 66±astronomical units and an orbital period of 424±25 years. This planet should be a challenge to be detected using direct imaging due to the presence of dust particles obscuring it, but could be detected and confirmed via high-resolution spectroscopic observations.[14]

Another planet candidate around SAO 206462 has been detected using observations of the JWST's NIRCam imaging instrument, with low signal-to-noise ratio, a mass of 0.8±0.3 MJ and a separation of 300 astronomical units. It has been dubbed CC1 (Companion candidate 1). Objects more massive than 2.2 MJ at distances of up to 120 AU have been ruled out by the observations.[15]

A third planet candidate was detected by direct imaging in 2025, at the root of one of the disk's spiral arms. The object has a mass estimated at 2 MJ, and is highly embedded in gas and dust, possibly having its own protoplanetary disk. It has a separation of 28 AU from the host star and is likely shepherding the inner part of the disk.[13]

References

  1. Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific 99 (617): 695. doi:10.1086/132034. Bibcode1987PASP...99..695R  Constellation record for this object at VizieR.
  2. 2.0 2.1 2.2 2.3 2.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  3. 3.0 3.1 3.2 3.3 "HD 135344". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+135344. 
  4. 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  5. 5.0 5.1 5.2 "SAO 206462". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=SAO+206462. 
  6. 6.0 6.1 6.2 6.3 6.4 6.5 6.6 Stolker, T. et al. (July 2025). "Direct imaging discovery of a young giant planet orbiting on Solar System scales". Astronomy & Astrophysics 700: A21. doi:10.1051/0004-6361/202555064. Bibcode2025A&A...700A..21S. 
  7. Stassun, Keivan G.; Oelkers, Ryan J.; Paegert, Martin et al. (2019-10-01). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. ISSN 0004-6256. Bibcode2019AJ....158..138S. 
  8. Gáspár, András; Rieke, George H.; Ballering, Nicholas (2016-08-01). "The Correlation between Metallicity and Debris Disk Mass". The Astrophysical Journal 826 (2): 171. doi:10.3847/0004-637X/826/2/171. ISSN 0004-637X. Bibcode2016ApJ...826..171G. 
  9. Guzmán-Díaz, J.; Mendigutía, I.; Montesinos, B.; Oudmaijer, R. D.; Vioque, M.; Rodrigo, C.; Solano, E.; Meeus, G. et al. (2021). "Homogeneous study of Herbig Ae/Be stars from spectral energy distributions and Gaia EDR3". Astronomy & Astrophysics 650: A182. doi:10.1051/0004-6361/202039519. Bibcode2021A&A...650A.182G. 
  10. Coulson, I. M.; Walther, D. M. (June 1995). "SAO 206462 - a solar-type star with a dusty, organically rich environment". Monthly Notices of the Royal Astronomical Society 274 (4): 977–986. doi:10.1093/mnras/274.4.977. Bibcode1995MNRAS.274..977C. 
  11. Grady, C. A.; Schneider, G.; Sitko, M. L.; Williger, G. M.; Hamaguchi, K.; Brittain, S. D.; Ablordeppey, K.; Apai, D. et al. (2009). "Revealing the Structure of a Pre-Transitional Disk: The Case of the Herbig F Star SAO 206462 (HD 135344B)". The Astrophysical Journal 699 (2): 1822. doi:10.1088/0004-637X/699/2/1822. Bibcode2009ApJ...699.1822G. 
  12. Phillips, Tony (31 October 2011). "A Star with Spiral Arms". http://science.nasa.gov/science-news/science-at-nasa/2011/31oct_spiralarms. 
  13. 13.0 13.1 13.2 13.3 Maio, F.; Fedele, D.; Roccatagliata, V.; Facchini, S.; Lodato, G.; Desidera, S.; Garufi, A.; Mesa, D. et al. (2025-06-27). "Unveiling a protoplanet candidate embedded in the HD 135344B disk with VLT/ERIS" (in en). Astronomy & Astrophysics 699: L10. doi:10.1051/0004-6361/202554472. ISSN 0004-6361. Bibcode2025A&A...699L..10M. 
  14. 14.0 14.1 14.2 Xie, Chen; Xie, Chengyan; Ren, Bin B.; Benisty, Myriam; Ginski, Christian; Fang, Taotao; Casassus, Simon; Bae, Jaehan et al. (2024-12-18). "Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS): Dynamical Evidence of a Spiral-Arm-Driving and Gap-Opening Protoplanet from SAO 206462 Spiral Motion". Universe 10 (12): 465. doi:10.3390/universe10120465. Bibcode2024Univ...10..465X. 
  15. 15.0 15.1 15.2 Cugno, Gabriele; Leisenring, Jarron; Wagner, Kevin R.; Mullin, Camryn; Dong, Roubing; Greene, Thomas; Johnstone, Doug; Meyer, Michael R. et al. (2024-01-05). "JWST/NIRCam Imaging of Young Stellar Objects. II. Deep Constraints on Giant Planets and a Planet Candidate Outside of the Spiral Disk Around SAO 206462". The Astronomical Journal 167 (4): 182. doi:10.3847/1538-3881/ad1ffc. Bibcode2024AJ....167..182C.