All names: Gaia DR3 679450494649048832, SDSS J082031.30+252558.8, WD 0817+255, Gaia EDR3 679450494649048832, SDSS J082031.30+252558.7, Gaia DR2 679450494649048832, [HHD2009] SDSS J0820+2525, SDSS J082031.31+252558.8
| Parameter | Unit | Gaia EDR3 | Pan-STARRS DR1 | SDSS DR12 | Gaia DR2 | Stilism | sdss-wdms.org (29/04/2016) | Simbad | Eisenstein et al. 2006 | White Dwarf Catalog (McCook & Sion 1999) | Kleinman et al. 2013 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Right ascension | 08 20 31.31 (0.3) | 08 20 31.31 | 08 20 31.31 (0.3) | 08 20 31.30 | 08 20 31.31 (0.3) | 08 20 31.31 | 08 20 30.94 | 08 20 31.31 | |||
| Declination | 25 25 58.82 (0.2) | 25 25 58.79 | 25 25 58.82 (0.2) | 25 25 58.69 | 25 25 58.85 (0.2) | 25 25 58.78 | 25 25 52.68 | 25 25 58.79 | |||
| Spectral type | DA+M | DA+M | DA+M | DA dM | DA+M | ||||||
| Effective temperature | [K] | 20098.0 (1140) | 9582.0 (93) | 9431.0 (104) | |||||||
| log(g) | [cgs] | 7.75 (0.2) | 8.92 (0.08) | 8.89 (0.1) | |||||||
| Mass | [M☉] | 0.49 (0.1) | |||||||||
| log(Luminosity) | [L☉] | ||||||||||
| Cooling age | [Gyr] | ||||||||||
| log(H/He) | |||||||||||
| log(C/He) | |||||||||||
| log(Ca/He) | |||||||||||
| log(Ca/H) | |||||||||||
| Parallax | [mas] | 1.75 (0.3) | 1.13 (0.4) | 1.75 (0.3) | |||||||
| Distance | [pc] | 570.36 (111) | 884.20 (337) | 132.00 (2) | 570.35 (111) | ||||||
| Composition | |||||||||||
| Proper motion (right ascension) | [mas/yr] | 1.390452912 (0.3) | 0.60940921 (0.7) | 1.39 (0.3) | -2.0 | ||||||
| Proper motion (declination) | [mas/yr] | -1.906471612 (0.3) | -1.455567574 (0.4) | -1.906 (0.3) | 0.0 | ||||||
| Variability | |||||||||||
| Magnetic | |||||||||||
| Bd | [MG] | ||||||||||
| Infrared excess (disk) | |||||||||||
| Binarity | WDMS | WDMS | WDMS | ||||||||
| B magnitude | |||||||||||
| V magnitude | |||||||||||
| R magnitude | |||||||||||
| I magnitude | |||||||||||
| J magnitude | 17.43 (0.02) | ||||||||||
| H magnitude | |||||||||||
| K magnitude | |||||||||||
| u magnitude | 19.59 (0.03) | 19.59 | 19.57 (0.03) | 19.59 (0.03) | 19.59 | 19.61 (0.03) | |||||
| g magnitude | 19.51 (0.01) | 19.51 | 19.50 (0.01) | 19.51 (0.02) | 19.51 | 19.53 (0.02) | |||||
| r magnitude | 19.73 (0.02) | 19.74 | 19.71 (0.02) | 19.74 (0.02) | 19.74 | 19.76 (0.02) | |||||
| i magnitude | 19.39 (0.02) | 19.40 | 19.38 (0.02) | 19.40 (0.02) | 19.40 | 19.42 (0.02) | |||||
| z magnitude | 18.79 (0.03) | 18.81 | 18.79 (0.03) | 18.80 (0.04) | 18.81 | 18.81 (0.04) | |||||
| G magnitude | 19.43 (0.05) | 19.46 | 19.43 (0.004) | ||||||||
| BP magnitude | 19.69 (0.05) | 19.57 | |||||||||
| RP magnitude | 18.93 (0.05) | 18.86 | |||||||||
| Pan g magnitude | 19.58 (0.01) | ||||||||||
| Pan r magnitude | 19.75 (0.009) | ||||||||||
| Pan i magnitude | 19.43 (0.009) | ||||||||||
| Pan z magnitude | 18.95 (0.01) | ||||||||||
| Pan y magnitude | 18.67 (0.03) | ||||||||||
| E(B-V) | 0.031 | ||||||||||
* 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.