All names: SDSS J164240.42+391731.40, Gaia DR2 1355625376655941120, SDSS J164240.41+391731.3, SDSS J164240.42+391731.4, SDSS J164240.42+391731.3, WD 1640+393, Gaia EDR3 1355625376655941120, SDSS J164240.41+391731.4, Gaia DR3 1355625376655941120, GALEX J164240.3+391732
| Parameter | Unit | Gaia EDR3 | Pan-STARRS DR1 | SDSS DR12 | Genest-Beaulieu & Bergeron 2019 (spectroscopic) | Genest-Beaulieu & Bergeron 2019 (photometric) | Gaia DR2 | Stilism | Koester & Kepler 2015 | Vincent et al. 2024 | Simbad | Eisenstein et al. 2006 | White Dwarf Catalog (McCook & Sion 1999) | Kleinman et al. 2013 | Vincent et al. 2023 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Right ascension | 16 42 40.40 (0.1) | 16 42 40.41 | 16 42 40.40 (0.2) | 16 42 40.40 | 16 42 40.42 (0.1) | 16 42 40.43 | 16 42 40.18 | 16 42 40.42 | |||||||
| Declination | 39 17 31.53 (0.1) | 39 17 31.36 | 39 17 31.52 (0.2) | 39 17 31.53 | 39 17 31.38 (0.1) | 39 17 31.34 | 39 17 30.84 | 39 17 31.36 | |||||||
| Spectral type | DB | DBAZ | DBA: | DBA: | DBAZ: | DB | |||||||||
| Effective temperature | [K] | 15411.0 | 14057.0 | 13681.0 (134) | 15698.0 (1218) | 15122.0 (181) | 14466.0 (286) | ||||||||
| log(g) | [cgs] | 8.85 | 8.19 | 8.00 (0) | 8.29 (0.1) | 8.95 (0.07) | 8.89 (0.2) | ||||||||
| Mass | [M☉] | 1.114 | 0.704 | 0.771 (0.09) | |||||||||||
| log(Luminosity) | [L☉] | ||||||||||||||
| Cooling age | [Gyr] | ||||||||||||||
| log(H/He) | -4.682 | -4.97 (0.4) | |||||||||||||
| log(C/He) | |||||||||||||||
| log(Ca/He) | <-8.29 | ||||||||||||||
| log(Ca/H) | |||||||||||||||
| Parallax | [mas] | 3.78 (0.1) | 3.96 (0.2) | 3.78 | 3.78 (0.1) | ||||||||||
| Distance | [pc] | 264.81 (1e+01) | 252.35 (12) | 275.00 | 264.81 | 264.81 (1e+01) | |||||||||
| Composition | |||||||||||||||
| Proper motion (right ascension) | [mas/yr] | -13.12027393 (0.2) | -13.44855571 (0.3) | -13.12 (0.2) | -6.1 | ||||||||||
| Proper motion (declination) | [mas/yr] | 9.36351406 (0.2) | 9.65220121 (0.5) | 9.364 (0.2) | 1.2 | ||||||||||
| Variability | |||||||||||||||
| Magnetic | |||||||||||||||
| Bd | [MG] | ||||||||||||||
| Infrared excess (disk) | |||||||||||||||
| Binarity | |||||||||||||||
| B magnitude | |||||||||||||||
| V magnitude | |||||||||||||||
| R magnitude | |||||||||||||||
| I magnitude | |||||||||||||||
| J magnitude | |||||||||||||||
| H magnitude | |||||||||||||||
| K magnitude | |||||||||||||||
| u magnitude | 18.55 (0.02) | 18.55 (0.01) | 18.56 (0.02) | 18.56 | 18.54 (0.02) | ||||||||||
| g magnitude | 18.62 (0.008) | 18.62 (0.008) | 18.63 (0.02) | 18.62 | 18.61 (0.02) | ||||||||||
| r magnitude | 18.88 (0.01) | 18.88 (0.01) | 18.87 (0.02) | 18.86 | 18.87 (0.02) | ||||||||||
| i magnitude | 19.08 (0.01) | 19.08 (0.01) | 19.08 (0.02) | 19.07 | 19.07 (0.02) | ||||||||||
| z magnitude | 19.42 (0.05) | 19.42 (0.05) | 19.39 (0.05) | 19.39 | 19.39 (0.05) | ||||||||||
| G magnitude | 18.72 (0.02) | 18.76 | 18.72 | 18.72 (0.003) | |||||||||||
| BP magnitude | 18.71 (0.02) | 18.68 | |||||||||||||
| RP magnitude | 18.90 (0.03) | 18.82 | |||||||||||||
| Pan g magnitude | 18.64 (0.006) | ||||||||||||||
| Pan r magnitude | 18.87 (0.008) | ||||||||||||||
| Pan i magnitude | 19.11 (0.006) | ||||||||||||||
| Pan z magnitude | 19.32 (0.02) | ||||||||||||||
| Pan y magnitude | 19.49 (0.04) | ||||||||||||||
| E(B-V) | 0.018 | ||||||||||||||
* Constant surface field
Spectra without link are available upon request
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.