X Ophiuchi
catalogues and names
| catalogues and names | X Oph, HR 7002, HD 172171, SAO 123744, BD +8 3780, WDS 18384+0850 |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
| position (J2000) | RA: 18h 38min 21sec | DEC: +8° 50' 2'' | ||
| position (2000.72) | RA: 18h 38min 23sec | DEC: +8° 50' 4'' | ||
| position (B1900) | RA: 18h 33min 34.1sec | DEC: +8° 44' 48'' | ||
| proper motion (J2000) | RA: -0.014 arcsec/a | DEC: 0.006 arcsec/a | ||
| radial velocity | -71 km/s note: variable radial velocity |
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| trigonometric parallax | 0.011 arcsec | |||
| galactic coordinates | longitude: 39.35° | latitude: 6.9° | ||
| note (category: dynamical parallaxes): | 0.002". |
magnitude
| visual magnitude | 6.4 (original HR magnitude) |
spectral / color information
| spectral class | M6IIIe+K1III |
| B-V-magnitude | 1.32 |
| U-B-magnitude | 0.89 |
| IR-note | object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978) |
variability information
| variable star identification | X Oph |
| note (category: variability): | ADS 11524A, M 5.9 - 9.2v, 334.39d. |
double/multiple star system information
| separation | 0.4 arcsec |
| mag difference (of double or brightest multiple) | 2.2 |
| note (category: double and multiple data): | Var. MBE+K1III, 8.8, 485.3y, a = 0.34". Masses A, 15.9; B, 5.0 solar. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 18h 38min 21.131sec | DEC: +8° 50' 2.34'' | ±0.43 arcsec | source: 16 |
| position (2000.72) | RA: 18h 38min 23sec | DEC: +8° 50' 4'' | JD: 2451806.35 | |
| proper motion (J2000) | RA: 0.0001 arcsec/a | DEC: 0.012 arcsec/a | source: 25 | |
| radial velocity | -71 km/s | source: 25 | ||
| trigonometric parallax | 0.011 arcsec | ±0.001 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 39.35° | latitude: 6.9° | ||
magnitude:
| visual | 5.9 (observed) | source: 25 |
| photographic | 8.9 | source: 16 |
spectral information:
| spectral class | M0 | source: 96 | |
| Morgan-Keenan | M6IIIe+K1III | source: 25 | |
| B-magnitude | 7.22 ±0.05 | B-V-magnitude | 1.32 |
| U-magnitude | 8.11 ±0.05 | U-B-magnitude | 0.89 |
variability information:
| variability type | 180 |
| var. amplitude | 3.3 |
| var. period | 328.85 |
| var. epoch | 2444729 4. May 1981, 12:00:00 UT |
| next max light | 2451963.7 23. February 2001, 04:48:00 UT |
double/multiple star system information:
| separation between brightest and second brightest component | 0.5 arcsec |
| magnitude difference between brightest and second brightest component | 0.1 |
| position angle | 134 ° |
sources:
| 16 | PPM North and PPM South Catalogs and PPM Supplement |
| Roser, S., and U. Bastian, "Catalogue of Positions and Proper Motions," A&AS, Vol. 74, p. 449, 1988, and Bastian, U., et al., "Catalogue of Positions and Proper Motions - South," 1993 | |
| 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 | |
| 30 | GCVS, 4th edition |
| Kholopov, P.N., et al., General Catalogue of Variable Stars, fourth edition, Moscow: Nauka Publishing House, 1985-88 | |
| 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: 18h 35min 57.512sec | DEC: +8° 47' 19.71'' | ±0.086 arcsec |
| position (2000.72) | RA: 18h 38min 24sec | DEC: +8° 50' 4'' | JD: 2451806.35 |
| position (J2000) | RA: 18h 38min 21.026sec | DEC: +8° 50' 1.79'' | |
| proper motion B1950 (FK4) | RA: -0.0011 arcsec/a | DEC: 0.007 arcsec/a | ±0.022 arcsec/a in RA ±0.018 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0.0009 arcsec/a | DEC: 0.006 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 6.4 (accuracy: 1 decimal) |
| source of visual magnitude data | Source cited in source catalog introduction. |
spectral information:
| spectral class | M6e |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
remarks for duplicity and variability
| Variable star in visual magnitude in source catalog |
catalogues
| source catalogue | GC, catalogue number: 25485 |
| Durchmusterung | BD+08 3780 |
| Boss General Catalogue | 25485 |
| Henry Draper Catalogue | 172171 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 18h 38.4min | DEC: +8° 50' |
| proper motion (J2000) | RA: 0.006 arcsec/a | DEC: 0.015 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 |
| - | 1900 | 57 | 195° | 0.2'' | 8.5 | 8.6 | K1III | HU 198 |
| 1991 | 134° | 0.5'' |
discoverer information:
| discoverer code | discoverer | reference |
| HU 198 | Hussey, W.J. | - |
notes:
| note | X Oph, a Mira-type variable. A premature orbit has been computed. However, the apparent motion is nearly rectilinear. Spectrum composite; K1III+M6IIIe. |
data from 4th Catalog of Orbits of Visual Binaries (Worley+, 1983)
position:
| position (B1900) | RA: 18h 33.6min | DEC: +8° 45' |
magnitudes, spectral classes, orbital elements:
| author: | P. Baize |
| date of observation: | 1975 |
| spectral class component B: | K1III |
| spectral class component B: | K1III |
| period [y]: | 485.3 |
| semi-major axis [arcsec]: | 0.34 |
| inclination [deg]: | 150.6 |
| node [deg]: | 72.9 |
| eccentricity: | 0.715 |
| time of periastron passage: | 1873.6 |
| grade: | indeterminate |
| reference: | Astron. Astrophys. Suppl. 39, 88; 1980. |
| notes | The M5e star is the Mira-type variable X Oph, P = 334 d, and at minimum often fainter than the K1 star. The motion so far is rectilinear. |