o2Eridani
catalogues and names
| catalogues and names | o2Eri, NSV 15931, 40 Eri, HR 1325, HD 26965, SAO 131063, BD -7 780, 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 (2000.73) | RA: 4h 15min 18sec | DEC: -7° 39' 6'' | ||
| position (B1900) | 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 |
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| trigonometric parallax | 0.209 arcsec | |||
| galactic coordinates | longitude: 200.72° | latitude: -38° | ||
| 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 | |
| IR-note | object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978) |
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 |
| position (2000.73) | RA: 4h 15min 18sec | DEC: -7° 39' 6'' | JD: 2451811.02 | |
| 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 arcsec | ±0.021 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 200.72° | latitude: -38° | ||
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 (B1950) | RA: 4h 12min 58.161sec | DEC: -7° 43' 45.89'' | ±0.01 arcsec |
| position (2000.73) | RA: 4h 15min 26sec | DEC: -7° 36' 13'' | JD: 2451811.02 |
| position (J2000) | RA: 4h 15min 16.321sec | DEC: -7° 39' 9.89'' | |
| proper motion B1950 (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. |
data from 4th Catalog of Orbits of Visual Binaries (Worley+, 1983)
position:
| position (B1900) | RA: 4h 10.8min | DEC: -7° 49' |
magnitudes, spectral classes, orbital elements:
| author: | W.D. Heintz |
| date of observation: | 1973 |
| magnitude of component A: | 9.51 |
| magnitude of component B: | 9.51 |
| spectral class component B: | DA |
| spectral class component B: | DA |
| period [y]: | 252.1 |
| semi-major axis [arcsec]: | 6.943 |
| inclination [deg]: | 108.9 |
| node [deg]: | 150.9 |
| equinox of node: | 2000 |
| eccentricity: | 0.41 |
| time of periastron passage: | 1849.6 |
| dates of ephemeris: | 1974-1984 |
| grade: | reliable |
| reference: | Astron. J. 79, 819; 1974. |
| notes | Star A (mag. 4.43, 82", K0V) is physical, and also named omicron-2 Eridani. Star C is a flare suspect. |