UW Canis Majoris
catalogues and names
| catalogues and names | UW CMa, 29 CMa, HR 2781, HD 57060, SAO 173444, CD -24 5173 |
| constellation | Canis Major |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
| position (J2000) | RA: 7h 18min 40.3sec | DEC: -24° 33' 32'' | ||
| position (2000.73) | RA: 7h 18min 42sec | DEC: -24° 33' 37'' | ||
| position (B1900) | RA: 7h 14min 30.5sec | DEC: -24° 22' 34'' | ||
| proper motion (J2000) | RA: -0.006 arcsec/a | DEC: 0 arcsec/a | ||
| radial velocity | -11 km/s note: spectroscopic binaries, double lined spectra note: orbital data avaible |
|||
| rotational velocity | 136 km/s (uncertain) (variable) | |||
| galactic coordinates | longitude: 237.82° | latitude: -5.37° | ||
magnitude
| visual magnitude | 4.98 (V on UBV Johnson system) |
spectral / color information
| spectral class | O7Ia:fp |
| B-V-magnitude | -0.15 |
| U-B-magnitude | -1.01 |
| R-I-magnitude | |
| IR-note | object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978) |
| note (category: spectra): | Weak C IV for its luminosity class of Ia. Variously classified O7f, O7.5If, O8.5If, O7e + O7:, O8f + O8f. |
| note (category: colors): | Color excess E(B-V) = +0.18. |
variability information
| variable star identification | UW CMa |
| note (category: variability): | EB 4.84 - 5.33V, 4.5 - 4.8p, amp. 0.45V, 4.393407d. Sp. lines vary within about 1 hr. Variable polarization. |
double/multiple star system information
| note (category: spectroscopic binaries): | 4.3934d, K 222.5k/s, V0 +13.5k/s, asini 13.4. Alternate orbit 4.3934d, K 242k/s, V0 +13.7k/s, asini 14.6. Nearly equal components. Mass loss from primary; asymmetrically expanding atmosphere. |
miscellaneous information
| note (category: group membership): | In HII reg. S310; probable runaway star; in cluster NGC 2362. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 7h 18min 40.362sec | DEC: -24° 33' 32.06'' | ±0.19 arcsec | source: 16 |
| position (2000.73) | RA: 7h 18min 42sec | DEC: -24° 33' 37'' | JD: 2451810.11 | |
| proper motion (J2000) | RA: -0.0007 arcsec/a | DEC: -0.015 arcsec/a | source: 25 | |
| radial velocity | -11 km/s | source: 25 | ||
| galactic coord. (B1950) | longitude: 237.83° | latitude: -5.37° | ||
magnitude:
| visual | 4.84 (observed) | source: 30 |
| photovisual | 5.1 | source: 16 |
spectral information:
| spectral class | O0 | source: 96 | |
| Morgan-Keenan | O7Ia:fp | source: 25 | |
| B-magnitude | 4.83 ±0.05 | B-V-magnitude | -0.15 |
| U-magnitude | 3.82 ±0.05 | U-B-magnitude | -1.01 |
variability information:
| variability type | 10 |
| var. amplitude | 0.49 |
| var. period | 4.39 |
| var. epoch | 2436185 12. December 1957, 12:00:00 UT |
| next max light | 2451813.4 25. September 2000, 21:36:00 UT |
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 | |
| 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: 7h 16min 35.375sec | DEC: -24° 27' 58.78'' | ±0.02 arcsec |
| position (2000.73) | RA: 7h 18min 42sec | DEC: -24° 33' 37'' | JD: 2451810.11 |
| position (J2000) | RA: 7h 18min 40.349sec | DEC: -24° 33' 31.77'' | |
| proper motion B1950 (FK4) | RA: -0.0008 arcsec/a | DEC: -0.002 arcsec/a | ±0.004 arcsec/a in RA ±0.004 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0.0005 arcsec/a | DEC: 0.001 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 4.9 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from Harvard or San Luis photometry. |
spectral information:
| spectral class | Oe |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
catalogues
| source catalogue | GC, catalogue number: 9734 |
| Durchmusterung | CD-24 5173 |
| Boss General Catalogue | 9734 |
| Henry Draper Catalogue | 57060 |
data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)
position:
| position (equinox 1950.0) | RA: 7h 16min 35.4sec | DEC: -24° 27' 59'' |
variability informations:
| variability type | EB/KE: | close binary eclipsing system |
| magnitute at max. brightness | 4.84 | |
| magnitute at min. brightness | 5.33 | |
| photometric system | visual, photovisual or Johnson's V | |
| epoch for maximum light [JD] | 2436185.358 12. December 1957, 20:35:31 UT |
|
| period [d] | 4.393407 | |
| next maximum light [JD] | 2451812.706699 25. September 2000, 04:57:39 UT |
spectral information
| spectral class | O7Ia:fp+OB |
references
| to a study | Vol. I GCVS (see Kholopov et al. 1985-1988) |
| to a chart/photograph | Vol. I GCVS (see Kholopov et al. 1985-1988) |
miscanellous
| ID in the GCVS catalogue | 14/36 |
| constellation | Canis Major |
| notes on existence | The star is equivalent to '0140037 UX'. |
| There are notes in published catalog. | |
variability type description
| variability type | description |
| EB | Eclipsing binary systems. These are binary systems with orbital planes so close to the observer's line of sight (the inclination i of the orbital plane to the plane orthogonal to the line of sight is close to 90 deg) that the components periodically eclipse each other. Consequently, the observer finds changes of the apparent combined brightness of the system with the period coincident with that of the components' orbital motion. EA Algol (Beta Persei)-type eclipsing systems. Binaries with spherical or slightly ellipsoidal components. It is possible to specify, for their light curves, the moments of the beginning and end of the eclipses. Between eclipses the light remains almost constant or varies insignificantly because of reflection effects, slight ellipsoidality of components, or physical variations. Secondary minima may be absent. An extremely wide range of periods is observed, from 0.2 to >= 10000 days. Light amplitudes are also quite different and may reach several magnitudes. EB Beta Lyrae-type eclipsing systems. These are eclipsing systems having ellipsoidal components and light curves for which it is impossible to specify the exact times of onset and end of eclipses because of a continuous change of a system's apparent combined brightness between eclipses; secondary minimum is observed in all cases, its depth usually being considerably smaller than that of the primary minimum; periods are mainly longer than 1 day. The components generally belong to early spectral types (B-A). Light amplitudes are usually <2 mag in V. EW W Ursae Majoris-type eclipsing variables. These are eclipsers with periods shorter than 1 days, consisting of ellipsoidal components almost in contact and having light curves for which it is impossible to specify the exact times of onset and end of eclipses. The depths of the primary and secondary minima are almost equal or differ insignificantly. Light amplitudes are usually <0.8 mag in V. The components generally belong to spectral types F-G and later. |
| KE | Contact systems of early (O-A) spectral type, both components being close in size to their inner critical surfaces. |