SDSS J141624.08+134826.7 (abbreviated SDSS J1416+1348) is a nearby wide binary system of two brown dwarfs, located in constellation Boötes. The system consists of L-type component A and T-type component B.
Component A was discovered in late 2009[1] from a search of Sloan Digital Sky Survey (SDSS) Data Release 7, an astronomical survey conducted at Apache Point Observatory in New Mexico, United States. It has two discovery papers: Bowler et al., 2009 and Schmidt et al., 2009.
Component B was discovered in early 2010 from UKIDSS Large Area Survey (ULAS) Data Release 5 & 6, an astronomical survey conducted on the United Kingdom Infrared Telescope (UKIRT) on Mauna Kea in Hawaii. It has also two discovery papers: Burningham et al., 2010 and Scholz, 2010. Burningham et al. discovered the whole system (independently of Bowler et al. and Schmidt et al.) by cross-matching the ULAS DR5 against SDSS DR7, and Scholz discovered component B by inspecting the UKIDSS finding charts around already found component A.
In 2012 was published the first relatively precise parallax of SDSS J1416+1348, measured at the Canada-France-Hawaii Telescope under The Hawaii Infrared Parallax Program: 109.9 ± 1.8 mas, corresponding to a distance 9.10 ± 0.15 pc (29.7 ± 0.5 ly). (Although, two parallaxes with large errors was previously published by Bowler et al. and Scholz).
| Source | Ref. | ||||
|---|---|---|---|---|---|
| Bowler et al., 2009 | 107 ± 34[2] | 9.3 | 30.5 | [3] | |
| Bowler et al., 2009 | 8.4 ± 1.9 | 27.4 ± 6.2 | |||
| Schmidt et al., 2009 | 8.0 ± 1.6 | 26.1 ± 5.2 | [4] | ||
| Burningham et al., 2010 | 5–15 | 16–49 | [5] | ||
| Scholz, 2010 | 7.9 ± 1.7 | 25.8 ± 5.5 | [6] | ||
| Burgasser et al., 2010 | 10.6 | 34.6 | [7] | ||
| Cushing et al., 2010 | 9.7 ± 0.1[8] | 31.6 ± 0.3 | [9] | ||
| The Hawaii Infrared Parallax Program (Dupuy & Liu, 2012) | 109.9 ± 1.8 | 9.10 ± 0.15 | 29.7 ± 0.5 | [10] |
Non-trigonometric distance estimates are marked in italic. The best estimate is marked in bold.
SDSS J1416+1348 has proper motion 165 mas·yr−1 with position angle 32 degrees, indicating motion in north-east direction on the sky. Corresponding right ascension and declination components of proper motion are 88.0 ± 2.8 mas/yr and 139.9 ± 1.3 mas/yr, respectively.[4] At distance 29.7 ly (assuming parallax 109.0 ± 1.8 mas),[10] corresponding tangential velocity is 7.1 km/s. Radial velocity of SDSS J1416+1348 is -42.2 ± 5.1 km/s.[4] (Negative radial velocity value indicates that SDSS J1416+1348 is now approaching to us). Total velocity of SDSS J1416+1348 relatively to Solar system is 42.8 km/s.
SDSS J1416+1348 space motions estimates
| Source | Vtan, km/s[11] | Ref. | ||||||
|---|---|---|---|---|---|---|---|---|
| Bowler et al., 2009 | 151 ± 8 | 33 ± 4 | 82 | 127 | 6.5 | –38 ± 10 | ||
| Schmidt et al., 2009 | 165 | 32 | 88.0 ± 2.8 | 139.9 ± 1.3 | 7.1 | -42.2 ± 5.1 | ||
| Scholz, 2010 | 163 | 32 | 86.2 ± 2.6 | 138.8 ± 2.6 | 7.1 | |||
| 165 | 32 | 88 ± 3 | 140 ± 2 | 7.1 | -87 ± 33 | |||
| Dupuy & Liu, 2012 | 161.3 ± 2.8 | 36.1 ± 1.2 | 95.1 ± 3.0 | 130.3 ± 3.0 | 7.1 |
The most accurate estimates are marked in bold.
Space motion of SDSS J1416+1348 indicates that it is member of Galactic thin disk population.[3] [6] [4]
Since SDSS J1416+1348 moves much faster in radial direction than in tangential direction, and radial velocity is negative, this brown dwarf system should pass the Solar System in the future at a much smaller distance than today's distance. Proper motion and radial velocity values from Schmidt et al., 2009 and parallax from Dupuy & Liu, 2012, assuming motion with constant velocity along straight line, yield minimal distance 4.9 ly circa year 207100.
Solar encounter chronology, assuming motion with constant velocity in a straight line relative to the Solar System:[12]
| Date | Constellation | Note | ||
|---|---|---|---|---|
| 759300 BC | 137.96 | Virgo/Boötes | transition to constellation Boötes | |
| 493000 BC | 100 | Boötes | approach to a distance of 100 ly | |
| 141600 BC | 50 | Boötes | approach to a distance of 50 ly | |
| 300 BC | 30 | Boötes | approach to a distance of 30 ly | |
| 2000 | 29.68 | Boötes | near present time | |
| 71300 | 20 | Boötes | approach to a distance of 20 ly | |
| 107900 | 15 | Boötes | approach to a distance of 15 ly | |
| 146200 | 10 | Boötes | approach to a distance of 10 ly | |
| 162900 | 8.01 | Boötes/Corona Borealis | transition to constellation Corona Borealis | |
| 168000 | 7.46 | Corona Borealis/Boötes | transition to constellation Boötes | |
| 170600 | 7.18 | Boötes/Hercules | transition to constellation Hercules | |
| 186500 | 5.76 | transition to constellation Draco | ||
| 202000 | 5 | Draco | approach to a distance of 5 ly | |
| 203600 | 4.97 | Draco/Cygnus | transition to constellation Cygnus | |
| 207100 | 4.95 | Cygnus | minimal distance | |
| 207600 | 4.95 | Cygnus/Cepheus | transition to constellation Cepheus | |
| 212200 | 5 | Cepheus | removal to a distance of 5 ly | |
| 212800 | 5.01 | Cepheus/Cygnus | transition to constellation Cygnus | |
| 215300 | 5.08 | Cygnus /Cepheus | transition to constellation Cepheus | |
| 215600 | 5.09 | Cepheus/Lacerta | transition to constellation Lacerta | |
| 222500 | 5.41 | Lacerta/Andromeda | transition to constellation Andromeda | |
| 262300 | 9.3 | Andromeda/Pisces | transition to constellation Pisces | |
| 268000 | 10 | Pisces | removal to a distance of 10 ly | |
| 306400 | 15 | Pisces | removal to a distance of 15 ly | |
| 343000 | 20 | Pisces | removal to a distance of 20 ly | |
| 410500 | 29.44 | Pisces/Cetus | transition to constellation Cetus | |
| 414500 | 30 | Cetus | removal to a distance of 30 ly | |
| 507000 | 43.07 | Cetus | transition to southern hemisphere | |
| 555900 | 50 | Cetus | removal to a distance of 50 ly | |
| 907200 | 100 | Cetus | removal to a distance of 100 ly |
SDSS J1416+1348 is an old system (age estimates: >0.8 Gyr,[4] ~10 Gyr,[5] ~5 Gyr,[6] 2–10 Gyr,[7] >3.2 Gyr[9]), and, probably, possesses low metallicity.[5] Its two components are separated at angular distance 9.81 arcsec, corresponding to a projected separation 89.3 ± 1.5 a. u.[10] The system's orbit semi-major axis estimate is 104 a. u.[10]
The primary (brighter) component (SDSS J141624.08+134826.7 is its full designation; also known as SDSS J1416+13A) is a brown dwarf of spectral type sdL7,[13] or L6,[3] [6] [10] or L5,[4] or d/sdL7.[5] It has unusually blue near-infrared J−KS color.[5] [6] [4] [7] According to Cushing et al. 2010, its peculiar spectrum is primarily a result of thin condensate clouds, and also vertical mixing occurs in its atmosphere.[9] However, in Burgasser et al., 2010 it was suggested that its (as well as component's B) peculiarities arise from age or metallicity, rather than cloud properties alone (since both A and B components have common peculiarities).[7]
The secondary (fainter) component (ULAS J141623.94+134836.3, abbreviated to ULAS J1416+1348, also known as SDSS J1416+13B) is a brown dwarf of spectral type T7.5,[7] [14] [15] or T7.5p.[5] [10] It has unusually extremely blue near-infrared color H−K,[5] very red optical-to-near-infrared color (z−Y > +2.3 and z−J > +3.1),[6] and extremely red color H−[4.5] = 4.86 ± 0.04[5] (it was suggested, that the latter may be explained by presence of a cooler unresolved companion to SDSS J1416+13B).[5] Also, its spectrum indicates high surface gravity and/or subsolar metallicity.[7]