UGPS J0722-0540 (abbreviation UGPS 0722-05 is used ) is a late-class brown dwarf in the constellation Unicorn . It is located at a distance of about 4.1 pc (13.4 light years) from the Sun [4] .
| UGPS J072227.51-054031.2 | |||
|---|---|---|---|
| Star | |||
| Observational data ( Age J2000.0 ) | |||
| Right ascension | |||
| Declination | |||
| Distance | 13.4 ± 0.1 St. years (4.12 ± 0.04 pc ) | ||
| Constellation | |||
| Astrometry | |||
| Radial velocity ( R v ) | 46.9 ± 2.5 [3] km / s | ||
| Own movement (μ) | RA: −904.14 ± 1.71 [4] Dec: 352.025 ± 1.21 [4] | ||
| Parallax (π) | 242.8 ± 2.4 [4] mas | ||
| Specifications | |||
| Spectral class | T9 [2] | ||
| physical characteristics | |||
| Age | 1–5 billion [3] years | ||
| Temperature | (502 ± 10) - (539 ± 12) [5] K | ||
| Luminosity | (6.3 ± 0.4) ⋅10 −7 [5] L ☉ | ||
| Rotation | 40 ± 10 km / s [3] | ||
| |||
| Database Information | |||
| SIMBAD | data | ||
Observation History
Opening
The star was discovered by Philip Lucas from the University of Hertfordshire , the discovery was announced in 2010. The image on which the object was detected was obtained on November 28, 2006 as part of the UKIRT Infrared Deep Sky Survey (UKIDSS); A picture confirming the discovery and allowing clarification of the star’s own motion was obtained on March 2, 2010. [1] The distance to the object was obtained from data on trigonometric parallax equal to 246 milliseconds of the arc. Initially, it was reported that the star is at a distance of 2.9 pc, due to which it was attributed to the top ten stars closest to the Sun, [7] but later measurements showed that the object is at a greater distance, approximately 4.1 +0.6
−0.5 pc. [one]
Adaptive Optics Observations
In 2010, Bouy and colleagues observed UGPS 0722-05 using adaptive optics at the Very Large Telescope . No companion objects were found with a magnitude of H ≲ 19.4 at angular distances greater than 50 msec, and at H ≲ 21.4 at angular distances greater than 100 msec. [eight]
Assignment to the spectral class
In 2010, Lucas and colleagues assigned the UGPS 0722-05 object the spectral class T10 and suggested that it might be the first object in the new spectral class. [one]
A 2011 article by Cushing and colleagues establishes the boundary between the spectral class T and the new spectral class Y - according to the spectrum features associated with NH 3 , and also introduced standards in the spectrum for the T / Y transition - between the classes T9 and Y0. UGPS 0722-05 was assigned to subclass T9, after which the spectrum standards for subclass T9 were adopted. [2]
Distance
For 2018, the most accurate estimate of the distance to UGPS 0722-05 was obtained by trigonometric parallax, published in 2013 by Leggett et al.: 0.2428 ± 0.0024 seconds of the arc , which corresponds to a distance of 4.12 ± 0.04 pc , or 13 , 43 ± 0.13 St. years old . [four]
Spatial Movement
UGPS 0722-05 has its own traffic of about 970 masl per year. [4] The radial velocity of UGPS 0722-05, measured by Bochanski and colleagues and published in 2011, is 46.9 ± 2.5 km / s. [3] A positive radial velocity indicates that UGPS 0722-05 is moving away from the Sun. A significant excess of radial velocity (46.9 km / s) over tangential velocity (19 km / s) shows that UGPS 0722-05 was much closer to the Sun in the past than it is now (assuming proper motion and parallax from Leggett et al. (2012) the minimum distance was 5.0 light years approximately 72,000 years BC, therefore, a star could be one of the closest stars to the Sun at that time).
Properties
The volume of the star approximately corresponds to the volume of Jupiter, but the mass is estimated to exceed the mass of Jupiter by 5–40 times. [1] Moreover, the star is less massive than the Epsilon of the Indian B a. Planets usually have masses of less than 13 masses of Jupiter. A study of the infrared spectrum of the star showed that the atmosphere of the object contains water mar and methane, and the surface temperature is 480–560 K. [1]
Notes
- ↑ 1 2 3 4 5 6 Lucas, PW; Tinney, CG; Burningham, B .; Leggett, SK; Pinfield, DJ; Smart, R .; Jones, HRA; Marocco, F .; Barber, RJ; Yurchenko, SN; Tennyson, J .; Ishii, M .; Tamura, M .; Day-Jones, AC; Adamson, A .; Allard, F .; Homeier, D. The discovery of a very cool, very nearby brown dwarf in the Galactic plane // Monthly Notices of the Royal Astronomical Society : journal. - Oxford University Press , 2010. - Vol. 408 , no. 1 . - P. L56 — L60 . - DOI : 10.1111 / j.1745-3933.2010.00927.x . - . - arXiv : 1004.0317 .
- ↑ 1 2 3 Cushing, Michael C .; Kirkpatrick, J. Davy; Gelino, Christopher R .; Griffith, Roger L .; Skrutskie, Michael F .; Mainzer, A .; Marsh, Kenneth A .; Beichman, Charles A .; Burgasser, Adam J .; Prato, Lisa A .; Simcoe, Robert A .; Marley, Mark S .; Saumon, D .; Freedman, Richard S .; Eisenhardt, Peter R .; Wright, Edward L. The Discovery of Y Dwarfs using Data from the Wide-field Infrared Survey Explorer (WISE ) // The Astrophysical Journal : journal. - IOP Publishing 2011. - Vol. 743 . - P. 50 . - DOI : 10.1088 / 0004-637X / 743/1/50 . - . - arXiv : 1108.4678 .
- ↑ 1 2 3 4 Bochanski, John J .; Burgasser, Adam J .; Simcoe, Robert A .; West, Andrew A. FIRE Spectroscopy of the Ultra-cool Brown Dwarf, UGPS J072227.51-054031.2: Kinematics, Rotation and Atmospheric Parameters // The Astronomical Journal : journal. - IOP Publishing 2011. - Vol. 142 , no. 5 . - P. 169 . - DOI : 10.1088 / 0004-6256 / 142/5/169 . - . - arXiv : 1109.2897 .
- ↑ 1 2 3 4 5 6 Leggett, SK; Saumon, D .; Marley, MS; Lodders, K .; Canty, J .; Lucas, P .; Smart, RL; Tinney, CG; Homeier, D .; Allard, F .; Burningham, Ben; Day-Jones, A .; Fegley, B .; Ishii, Miki; Jones, HRA; Marocco, F .; Pinfield, DJ; Tamura, M. The Properties of the 500 K Dwarf UGPS J072227.51-054031.2 and a Study of the Far-red Flux of Cold Brown Dwarfs (Eng.) // The Astrophysical Journal : journal. - IOP Publishing 2012. - Vol. 748 , no. 2 . - P. 74 . - DOI : 10.1088 / 0004-637X / 748/2/74 . - . - arXiv : 1201.2973 .
- ↑ 1 2 Dupuy, TJ; Kraus, AL Distances, Luminosities, and Temperatures of the Coldest Known Substellar Objects (English) // Science: journal. - 2013 .-- Vol. 341 , no. 6153 . - P. 1492-1495 . - DOI : 10.1126 / science.1241917 . - . - arXiv : 1309.1422 . - PMID 24009359 .
- ↑ Kirkpatrick, J. Davy ; Cushing, Michael C .; Gelino, Christopher R .; Griffith, Roger L .; Skrutskie, Michael F .; Marsh, Kenneth A .; Wright, Edward L .; Mainzer, A .; Eisenhardt, Peter R .; McLean, Ian S .; Thompson, Maggie A .; Bauer, James M .; Benford, Dominic J .; Bridge, Carrie R .; Lake, Sean E .; Petty, Sara M .; Stanford, SA; Tsai, Chao-Wei; Bailey, Vanessa; Beichman, Charles A .; Bloom, Joshua S .; Bochanski, John J .; Burgasser, Adam J .; Capak, Peter L .; Cruz, Kelle L .; Hinz, Philip M .; Kartaltepe, Jeyhan S .; Knox, Russell P .; Manohar, Swarnima; Masters, Daniel; Morales-Calderon, Maria; Prato, Lisa A .; Rodigas, Timothy J .; Salvato, Mara; Schurr, Steven D .; Scoville, Nicholas Z .; Simcoe, Robert A .; Stapelfeldt, Karl R .; Stern, Daniel; Stock, Nathan D .; Vacca, William D. The First Hundred Brown Dwarfs Discovered by the Wide-field Infrared Survey Explorer (WISE ) // The Astrophysical Journal : journal. - IOP Publishing 2011. - Vol. 197 , no. 2 . - P. 19 . - DOI : 10.1088 / 0067-0049 / 197/2/19 . - . - arXiv : 1108.4677v1 .
- ↑ Lucas, Philip W .; Tinney; Burningham Leggett Pinfield & Smart (2010), "Discovery of a very cool brown dwarf amongst the ten nearest stars to the Solar System", arΧiv : 1004.0317v1 [astro-ph.SR]
- ↑ Bouy, H .; Girard, JHV; Martín, EL; Huélamo, N .; Lucas, PW Adaptive optics observations of the T10 ultracool dwarf UGPS J072227.51-054031.2 (Eng.) // Astronomy and Astrophysics : journal. - EDP Sciences 2011. - Vol. 526 . - P. A55 . - DOI : 10.1051 / 0004-6361 / 201015289 . - . - arXiv : 1008.3046 .