LP 638-4

All names: Gaia DR2 2687733913283870336, LDS 749B, IDS 21271-0013 B, uvby98 980026010, CCDM J21322+0014B, G 26-10, GEN# +9.80026010, TIC 352817378, LSPM J2132+0015, UBV 18541, WD 2129+00, L 1002-16, IDS 21270-0013 B, LP 638-4, UBV M 5071, LP 638-004, ** LDS 749B, WDS J21322+0013B, USNO-B1.0 0902-00571211, LTT 16294, GEN# -0.00004234B, WD 2129+000, BD-00 4234B, CSI-00 4234 2, PHL 28, WD 2129+004, ** KUI 107B, Gaia DR3 2687733913283870336, LAWD 87, CSI+00-21297, Gaia EDR3 2687733913283870336, 2MASS J21321623+0015144, NLTT 51482, SDSS J213216.33+001514.5, GCRV 72252, UBV M 42732, FBS 2129+000, WDJ213216.23+001514.40, USNO 87, G26-10, G 93-21, JP11 5101, EGGR 145

Parameter Unit Gaia EDR3 Pan-STARRS DR1 Kilic et al. 2025 MWDD HE Gaia DR2 Bedard et al. 2017 Tremblay et al. 2017 Stilism Bergeron et al. 2011 Zuckerman et al. 2010 Voss et al. 2007 Weidemann and Koester 1995 Wegner et al. 1987 Vincent et al. 2024 Simbad Gentile Fusillo et al. 2018 White Dwarf Catalog (McCook & Sion 1999)
Right ascension 21 32 16.67 (0.02) 21 32 16.66 (0.04) 21 32 16.67 21 32 16.23 (0.02) 21 32 16.66 21 32 14.69
Declination 00 15 14.83 (0.02) 00 15 14.82 (0.04) 00 15 14.83 00 15 14.40 (0.02) 00 15 14.82 00 15 05.76
Spectral type DB DB DB DB DB DB DB DB DB4 DB4
Effective temperature [K] 13330.0 (90) 13725.0 14383.0 (231) 14380.0 (350) 14380.0 (351) 14000.0 14414.0 13000.0 13000.0 13956.0 (93)
log(g) [cgs] 7.97 (0.007) 8.01 8.27 (0.1) 8.26 (0.1) 8.26 (0.1) 8.00 8.03 (0.008)
Mass [M☉] 0.571 (0.006) 0.595 0.75 (0.09) 0.604 (0.006)
log(Luminosity) [L☉] -2.36
Cooling age [Gyr] 0.2662 0.3548
log(H/He) <-6.48 (2) <-5
log(C/He) <-7 <-6.5
log(Ca/He) <-11.1
log(Ca/H)
log(N/He)
log(O/He)
log(Na/He)
log(Mg/He)
log(Al/He)
log(Si/He)
log(P/He)
log(S/He)
log(Cl/He)
log(Sc/He)
log(Ti/He)
log(V/He)
log(Cr/He)
log(Mn/He)
log(Fe/He)
log(Co/He)
log(Ni/He)
log(Cu/He)
log(Zn/He)
log(Ga/He)
log(Ge/He)
log(Sr/He)
Parallax [mas] 23.29 (0.03) 23.40 (0.05) 23.16 (0.4) 23.29 23.29 (0.03) 23.40 (0.05) 33.10
Distance [pc] 42.94 (0.05) 42.74 (0.09) 43.20 (1) 43.18 (0.7) 49.00 42.94 42.94 (0.05) 42.74 (0.09) 30.21
Composition He He He He
Proper motion (right ascension) [mas/yr] 413.2789765 (0.03) 413.2279019 (0.08) 413.279 (0.03) 413.2279019
Proper motion (declination) [mas/yr] 27.20684724 (0.02) 27.27030436 (0.07) 27.207 (0.02) 27.27030436
Variability
Magnetic
Bd [MG]
Infrared excess (disk)
Binarity yes
B magnitude 14.63
V magnitude 14.67 (0.03) 15.27 14.73 14.67
R magnitude 14.68
I magnitude 14.68
J magnitude 14.89 (0.04)
H magnitude 15.05 (0.09)
K magnitude 15.22 (0.1)
u magnitude 14.49 (0.004) 14.50 (0.004)
g magnitude 14.52 (0.004) 14.52 (0.004)
r magnitude 14.78 (0.004) 14.78 (0.004)
i magnitude 15.59 (0.006) 15.51 (0.007)
z magnitude 15.23 (0.006) 15.22 (0.006)
G magnitude 14.64 (0.001) 14.66 14.64 14.64 (0.003) 14.66
BP magnitude 14.60 (0.001) 14.57 14.57
RP magnitude 14.69 (0.002) 14.70 14.70
Pan g magnitude 14.56 (0.0008)
Pan r magnitude 14.79 (0.004)
Pan i magnitude 15.03 (0.002)
Pan z magnitude 15.24 (0.01)
Pan y magnitude 15.41 (0.004)
E(B-V) 0.001

* Constant surface field

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The Montreal White Dwarf Database is produced and maintained by Prof. Patrick Dufour (Université de Montréal) and Dr. Simon Blouin (University of Victoria). Please send database updates, corrections, suggestions or bug reports to patrick.dufour@umontreal.ca.