All names: SDSS J081840.74+204748.0, GALEX J081840.7+204748, Gaia DR3 675740604978228608, SDSS J081840.80+204748.1, Gaia DR2 675740604978228608, SDSS J081840.76+204748.0, SDSS J081840.75+204747.9, [HHD2009] SDSS J0818+2047, WIRED J081840.75+204748.0, WD 0815+209, SDSS J081840.75+204748.0, Gaia EDR3 675740604978228608
| Parameter | Unit | Gaia EDR3 | Pan-STARRS DR1 | SDSS DR12 | Bedard et al. 2020 | Gaia DR2 | Stilism | sdss-wdms.org (29/04/2016) | Simbad | White Dwarf Catalog (McCook & Sion 1999) | Kleinman et al. 2013 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Right ascension | 08 18 40.75 (0.3) | 08 18 40.75 | 08 18 40.75 (0.4) | 08 18 40.75 | 08 18 40.75 (0.3) | 08 18 40.78 | 08 18 40.76 | ||||
| Declination | 20 47 48.01 (0.2) | 20 47 48.05 | 20 47 48.01 (0.2) | 20 47 48.01 | 20 47 48.06 (0.2) | 20 47 41.28 | 20 47 48.00 | ||||
| Spectral type | DA+M | DA+M | DA+M | DA dM | DA+M | ||||||
| Effective temperature | [K] | 31296.0 (470) | 31853.0 (742) | 8791.0 (84) | |||||||
| log(g) | [cgs] | 7.68 (0.1) | 7.81 (0.2) | 9.24 (0.09) | |||||||
| Mass | [M☉] | 0.5 (0.04) | 0.56 (0.09) | ||||||||
| log(Luminosity) | [L☉] | -0.61 (0.08) | |||||||||
| Cooling age | [Gyr] | 0.0069 (0.0009) | |||||||||
| log(H/He) | |||||||||||
| log(C/He) | |||||||||||
| log(Ca/He) | |||||||||||
| log(Ca/H) | |||||||||||
| log(C/H) | |||||||||||
| log(N/H) | |||||||||||
| log(O/H) | |||||||||||
| log(Na/H) | |||||||||||
| log(Mg/H) | |||||||||||
| log(Al/H) | |||||||||||
| log(Si/H) | |||||||||||
| log(P/H) | |||||||||||
| log(S/H) | |||||||||||
| log(Sc/H) | |||||||||||
| log(Ti/H) | |||||||||||
| log(Cr/H) | |||||||||||
| log(Mn/H) | |||||||||||
| log(Fe/H) | |||||||||||
| log(Ni/H) | |||||||||||
| Parallax | [mas] | 1.03 (0.3) | 0.41 (0.4) | 1.03 (0.3) | |||||||
| Distance | [pc] | 971.92 (314) | 2466.26 (2631) | 455.00 (258) | 971.91 (314) | ||||||
| Composition | H | ||||||||||
| Proper motion (right ascension) | [mas/yr] | -5.403825102 (0.4) | -5.610605922 (0.7) | -5.404 (0.4) | |||||||
| Proper motion (declination) | [mas/yr] | -3.479435109 (0.3) | -2.874944079 (0.5) | -3.479 (0.3) | |||||||
| Variability | |||||||||||
| Magnetic | |||||||||||
| Bd | [MG] | ||||||||||
| Infrared excess (disk) | |||||||||||
| Binarity | WDMS | WDMS | |||||||||
| B magnitude | |||||||||||
| V magnitude | |||||||||||
| R magnitude | |||||||||||
| I magnitude | |||||||||||
| J magnitude | |||||||||||
| H magnitude | |||||||||||
| K magnitude | |||||||||||
| u magnitude | 19.22 (0.03) | 19.25 | 19.22 (0.03) | 19.24 | 19.22 (0.03) | ||||||
| g magnitude | 19.37 (0.01) | 19.38 | 19.36 (0.01) | 19.37 | 19.36 (0.03) | ||||||
| r magnitude | 19.66 (0.02) | 19.70 | 19.69 (0.02) | 19.69 | 19.68 (0.02) | ||||||
| i magnitude | 19.44 (0.02) | 19.44 | 19.44 (0.02) | 19.43 | 19.44 (0.02) | ||||||
| z magnitude | 19.02 (0.04) | 19.06 | 19.06 (0.05) | 19.05 | 19.05 (0.05) | ||||||
| G magnitude | 19.38 (0.04) | 19.42 | 19.38 (0.004) | ||||||||
| BP magnitude | 19.47 (0.04) | 19.31 | |||||||||
| RP magnitude | 19.02 (0.04) | 18.95 | |||||||||
| Pan g magnitude | 19.43 (0.006) | ||||||||||
| Pan r magnitude | 19.69 (0.03) | ||||||||||
| Pan i magnitude | 19.45 (0.01) | ||||||||||
| Pan z magnitude | 19.14 (0.01) | ||||||||||
| Pan y magnitude | 19.00 (0.02) | ||||||||||
| E(B-V) | 0.033 | ||||||||||
* 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.