SDSS 1557

SDSS 1557

Artist's impression of the SDSS1557 system. The white dwarf is the blue star that accretes material from a stream. Right next to it is the brown dwarf and around the binary is the debris disk.
Credit: International Gemini Observatory/NOIRLab/NSF/AURA/UCL/University of Warwick/University of Sheffield//Mark Garlick
Observation data
Epoch J2000      Equinox J2000
Constellation Serpens
Right ascension 15h 57m 20.77s
Declination +09° 16′ 24.6″
Characteristics
Evolutionary stage post common envelope binary: white dwarf + brown dwarf
Spectral type DAZ + L4±1[1]
Astrometry
Proper motion (μ) RA: -10.202 ±0.198 mas/yr[2]
Dec.: -25.988 ±0.197 mas/yr[2]
Parallax (π)1.7767 ± 0.1974 mas[2]
Distanceapprox. 1631 ly
(500.0+19.8
−18.0 pc)[3]
Orbit[1]
PrimarySDSS 1557A
CompanionSDSS 1557B
Period (P)2.273153 ±0.000002 hrs
Semi-major axis (a)0.70 ± 0.02 R☉
Inclination (i)80 ±3[3]°
Semi-amplitude (K1)
(primary)		40.42 ±0.69 km/s
Semi-amplitude (K2)
(secondary)		288.3 ±3.0 km/s
Details[1][3]
SDSS 1557A
Mass0.447 ±0.043 M☉
Radius0.0162 ±0.0012 R☉
Surface gravity (log g)7.63 ±0.11 cgs
Temperature21800 ±800 K
Age33 ±5 (cooling age) Myr
SDSS 1557B
Mass66+5
−7 MJup
Radius1.054 ±0.242 RJup
Temperature1400 to 2500 K
Other designations
GALEX J155720.8+091625, WD 1554+094, SDSS J155720.78+091624.7, ULAS J155720.77+091624.6, EQ J1557+0916
Database references
SIMBADdata

SDSS 1557 (SDSS J155720.77+091624.6, WD 1554+094) is a binary system composed of a white dwarf and a brown dwarf. The system is surrounded by a circumbinary debris disk. The debris disk was formed when a minor planet was tidally disrupted around the white dwarf in the past.[1][3]

  1. ^ a b c d Cite error: The named reference Farihi2017 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Gaia EDR3 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference Amaro 2024 was invoked but never defined (see the help page).