o2Eridani
| catalogues and names | o2Eri, NSV 15931, 40 Eri, HR 1325, HD 26965, SAO 131063, WDS 04153-0739A |
| constellation | Eridanus |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
| note (category: star names): | Keid; Kied. |
position, motion, parallax:
| position (J2000) | RA: 4h 15min 16,3sec | DEC: -7° 39' 10'' |
| position (J1900) | RA: 4h 10min 40,2sec | DEC: -7° 48' 30'' |
| proper motion (J2000) | RA: -2,242 arcsec/a | DEC: -3,414 arcsec/a |
| radial velocity | -42 km/s note: variable radial velocity |
|
| trigonometric parallax | 0,209 arcsec | |
| note (category: dynamical parallaxes): | 0.199". |
magnitude
| visual magnitude | 4,43 (V on UBV Johnson system) |
spectral / color information
| spectral class | K1-V |
| B-V-magnitude | 0,82 |
| U-B-magnitude | 0,45 |
| R-I-magnitude | 0,45 |
variability information
| variable star identification | DY Eri |
| note (category: variability): | ADS 3093C; UV, min. 11.18V, +1.50 (B-V), 12.16 - 13.85U. X-ray source. |
double/multiple star system information
| number of components of multiple star system | 5 |
| separation | 83,4 arcsec |
| mag difference (of double or brightest multiple) | 5 |
| component ID | AB |
| note (category: double and multiple data): | BC 9.51 A2, 11.18 M4Ve, 252.1y, a = 6.943". Component B is white dwarf. Component A, CPM. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 4h 15min 16,314sec | DEC: -7° 39' 9,88'' | ±0,19 arcsec | source: 33 |
| proper motion (J2000) | RA: -0,1506 arcsec/a | DEC: -3,411 arcsec/a | source: 25 | |
| radial velocity | -42 km/s | source: 25 | ||
| trigonometric parallax | 0,209 | ±0,021 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 200,72° | latitude: -38° | ||
| GCI unit vector (J2000) | X: 0,437295 | Y: 0,889404 | Z: -0,133169 | |
magnitude:
| visual | 4,43 (observed) | source: 25 |
| photovisual | 4,5 | source: 2 |
| photographic | 5,3 | source: 2 |
spectral information:
| spectral class | G5 | source: 96 | |
| Morgan-Keenan | K0.5V | source: 25 | |
| B-magnitude | 5,25 ±0,05 | B-V-magnitude | 0,82 |
| U-magnitude | 5,7 ±0,05 | U-B-magnitude | 0,45 |
double/multiple star system information:
| separation between brightest and second brightest component | 83,4 arcsec |
| magnitude difference between brightest and second brightest component | 5,3 |
| position angle | 104 ° |
| component | magnitude | spectral class | catalogue(s)/name(s) |
| A | 4,43 | G5 | o2Eridani, 40 Eri, HR 1325, HD 26965, SAO 131063 |
| B | 9,51 | A |
sources:
| 2 | HD and HDE Catalogs |
| Cannon, A.J., and E.C. Pickering, Harvard Annals, Vols 91-99, 1918-24, Cambridge, Massachusetts: Harvard University; Cannon, A.J., Harvard Annals, Vol. 100, 1925-36, Cambridge, Massachusetts: Harvard University; and Cannon, A.J., and M. Walton Mayall, Harvard Annals, Vol. 112, 1949, Cambridge, Massachusetts: Harvard University | |
| 19 | WDS Catalog |
| Worley, C.E., and G.G. Douglass, Washington Catalog of Visual Double Stars 1996.0, United States Naval Observatory, 1996 | |
| 25 | Bright Star Catalogue, 5th edition |
| Hoffleit, D. and Warren, W.H. Jr., The Bright Star Catalogue, 5th Revised Edition, Version 2, 1994 | |
| 33 | Hipparcos Main Input Catalogue Version 2 |
| Turon, C., et al., The Hipparcos Input Catalogue, Version 2, CDS Bull. No. 43, p.5, 1993 | |
| 96 | SAO or HD/HDE Catalog |
| Reference from Value 1 or Reference from Value 2 | |
data from Smithsonian Astrophysical Observatory Star Catalog (SAO Staff 1966; USNO, ADC 1990)
position and proper motion:
| position (J1950) | RA: 4h 12min 58,161sec | DEC: -7° 43' 45,89'' | ±0,01 arcsec |
| position (J2000) | RA: 4h 15min 16,321sec | DEC: -7° 39' 9,89'' | |
| proper motion J1950 (FK4) | RA: -0,1501 arcsec/a | DEC: -3,42 arcsec/a | ±0,002 arcsec/a in RA ±0,002 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0,1507 arcsec/a | DEC: -3,411 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 4,5 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from Harvard or San Luis photometry. |
spectral information:
| spectral class | G5 |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
remarks for duplicity and variability
| Double star in Aitken's Double Star Catalogue (Aitken 1932) |
catalogues
| source catalogue | GC, catalogue number: 5138 |
| Durchmusterung | BD-07 780 |
| Boss General Catalogue | 5138 |
| Henry Draper Catalogue | 26965 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 4h 15,3min | DEC: -7° 39' |
| proper motion (J2000) | RA: 0 arcsec/a | DEC: 0 arcsec/a |
double/multiple star system information:
| component | year | number of measures | position angle | angular separation | magnitude of 1st component | magnitude of 2nd component | spectral class(es) | discoverer code |
| A-BC | 1825 | 58 | 107° | 83,5'' | 4,43 | 9,7 | G9V | STF 518 |
| 1970 | 104° | 83,4'' | ||||||
| Aa | 1850 | 12 | 197° | 128,3'' | 4,43 | 12,2 | G5 | STF 518 |
| 1907 | 51° | 114,2'' | ||||||
| Ab | 1850 | 5 | 279° | 99,4'' | 4,43 | 12,5 | G5 | STF 518 |
| 1907 | 8° | 211'' | ||||||
| BC | 1851 | often | 157° | 3,9'' | 9,52 | 11,17 | DA dM4e | STF 518 |
| 1994 | 338° | 8,9'' | ||||||
| BP | 1922 | 1 | 196° | 147'' | 9,7 | - | - | STF 518 |
| Bb | 1922 | 1 | 356° | 279,5'' | 9,7 | - | A | STF 518 |
discoverer information:
| discoverer code | discoverer | reference |
| STF 518 | Struve, F.G.W. | - |
notes:
| note | Omicron (2) Eri. Proper motion of A -2224 -3423. BC: P = 252yr., a = 6.94", motion retrograde. B is a white dwarf, and C is a flare star, DY Eri, and a strong X-ray source. Omicron (1) Eri at 83" is physical, and is a Delta Scuti star showing coronal X-ray emission. |