DY Eridani
catalogues and names
| catalogues and names | DY Eri, HD 26976, SAO 131065, BD -7 781, WDS 04153-0739B |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 4h 15min 22.01sec | DEC: -7° 39' 34.7'' | ±0.5 arcsec | source: 18 |
| position (2000.73) | RA: 4h 15min 24sec | DEC: -7° 39' 31'' | JD: 2451811.02 | |
| proper motion (J2000) | RA: -0.1468 arcsec/a | DEC: -3.44 arcsec/a | source: 18 | |
| galactic coord. (B1950) | longitude: 200.74° | latitude: -37.98° | ||
magnitude:
| visual | 9.51 (observed) | source: 20 |
| photovisual | 9.7 | source: 2 |
| photographic | 9.7 | source: 2 |
spectral information:
| spectral class | A | source: 29 | |
| Morgan-Keenan | M4.5Ve | source: 30 | |
| B-magnitude | 9.55 ±0.034 | B-V-magnitude | 0.04 |
| U-magnitude | 8.87 ±0.008 | U-B-magnitude | -0.68 |
variability information:
| variability type | 220 |
| var. amplitude | 1.72 |
double/multiple star system information:
| separation between brightest and second brightest component | 8.9 arcsec |
| magnitude difference between brightest and second brightest component | 1.65 |
| position angle | 338 ° |
| 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 | |
| 18 | Hipparcos Input Catalog Version 2 Annex |
| Turon, C., et al., "The Hipparcos Input Catalog, Version 2," Centre de Donnees Stellaires Information Bulletin, Vol. 43, p. 5, 1993 | |
| 19 | WDS Catalog |
| Worley, C.E., and G.G. Douglass, Washington Catalog of Visual Double Stars 1996.0, United States Naval Observatory, 1996 | |
| 20 | Catalogue of Homogeneous Means in the UBV System |
| Mermilliod, J.C., Catalogue of Homogeneous Means in the UBV System, Institut d'Astronomie, Universite de Lausanne, 1994 | |
| 29 | SAOJ2000 |
| SAO on FK5 at J2000, 1989 | |
| 30 | GCVS, 4th edition |
| Kholopov, P.N., et al., General Catalogue of Variable Stars, fourth edition, Moscow: Nauka Publishing House, 1985-88 | |
data from Smithsonian Astrophysical Observatory Star Catalog (SAO Staff 1966; USNO, ADC 1990)
position and proper motion:
| position (B1950) | RA: 4h 13min 3.655sec | DEC: -7° 44' 8.92'' | ±0.054 arcsec |
| position (2000.73) | RA: 4h 15min 32sec | DEC: -7° 36' 37'' | JD: 2451811.02 |
| position (J2000) | RA: 4h 15min 21.967sec | DEC: -7° 39' 34.29'' | |
| proper motion B1950 (FK4) | RA: -0.1469 arcsec/a | DEC: -3.44 arcsec/a | ±0.01 arcsec/a in RA ±0.012 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0.1475 arcsec/a | DEC: -3.431 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 9.7 (accuracy: 1 decimal) |
| source of visual magnitude data | Based on Durchmusterung magnitudes and visual estimates |
spectral information:
| spectral class | A |
| 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: 5140 |
| Durchmusterung | BD-07 781 |
| Boss General Catalogue | 5140 |
| Henry Draper Catalogue | 26976 |
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. |