RR Lyr
| catalogues and names | RR Lyr, HD 182989, SAO 48421 |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 19h 25min 27,961sec | DEC: +42° 47' 3,66'' | ±0,35 arcsec | source: 17 |
| proper motion (J2000) | RA: -0,0091 arcsec/a | DEC: -0,196 arcsec/a | source: 17 | |
| radial velocity | -72 km/s | source: 26 | ||
| trigonometric parallax | 0,011 | ±0,001 arcsec | source: 26 | |
| galactic coord. (B1950) | longitude: 74,96° | latitude: 12,3° | ||
| GCI unit vector (J2000) | X: 0,267389 | Y: -0,683473 | Z: 0,679241 | |
magnitude:
| visual | 7,1 (observed) | source: 31 |
| photographic | 8 | source: 16 |
spectral information:
| spectral class | F5 | source: 96 | |
| Morgan-Keenan | A8-F7 | source: 26 | |
| B-magnitude | 7,36 ±0,2 | B-V-magnitude | 0,3 |
| U-magnitude | 7,57 ±0,032 | U-B-magnitude | 0,15 |
variability information:
| variability type | 121 |
| var. amplitude | 1,06 |
| var. period | 0,57 |
| var. epoch | 2442923 24. May 1976, 12:00:00 UT |
| next max light | 2451621,77 18. March 2000, 06:28:48 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 | |
| 17 | ACRS |
| Corbin, T.E., and S.E. Urban, Astrographic Catalog Reference Stars, United States Naval Observatory, 1991 | |
| 26 | Bright Star Supplement |
| Hoffleit, D. and Warren, W.H. Jr., A Supplement to the Bright Star Catalogue, 1994 | |
| 30 | GCVS, 4th edition |
| Kholopov, P.N., et al., General Catalogue of Variable Stars, fourth edition, Moscow: Nauka Publishing House, 1985-88 | |
| 31 | CRM' (non-GCVS variable data) |
| Warren, W.H. Jr., Northern Hemisphere Catalog of Red Magnitudes, 1994 | |
| 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: 19h 23min 52,14sec | DEC: +42° 41' 11,91'' | ±0,044 arcsec |
| position (J2000) | RA: 19h 25min 27,833sec | DEC: +42° 47' 4,5'' | |
| proper motion J1950 (FK4) | RA: -0,011 arcsec/a | DEC: -0,184 arcsec/a | ±0,012 arcsec/a in RA ±0,01 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0,0105 arcsec/a | DEC: -0,186 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 7,2 (accuracy: 1 decimal) |
| source of visual magnitude data | Source cited in source catalog introduction. |
spectral information:
| spectral class | F5 |
| 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: 26836 |
| Durchmusterung | BD+42 3338 |
| Boss General Catalogue | 26836 |
| Henry Draper Catalogue | 182989 |
data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)
position:
| position (J1950) | RA: 19h 23min 52,1sec | DEC: +42° 41' 12'' |
variability informations:
| variability type | RRAB | pulsating variable star |
| magnitute at max. brightness | 7,06 | |
| magnitute at min. brightness | 8,12 | |
| photometric system | visual, photovisual or Johnson's V | |
| epoch for maximum light [JD] | 2442923,4193 24. May 1976, 22:03:48 UT |
|
| period [d] | 0,56686776 | |
| next maximum light [JD] | 2451621,43820944 17. March 2000, 22:31:01 UT |
|
| rising time | 19 % of period |
spectral information
| spectral class | A5.0-F7.0 |
references
| to a study | Vol. II GCVS |
| to a chart/photograph | Vol. I GCVS (see Kholopov et al. 1985-1988) |
miscanellous
| ID in the GCVS catalogue | 52/10 |
| constellation | Lyra |
| notes on existence | The star is equivalent to '0520011 RS'. |
| There are notes in published catalog. | |
variability type description
| variability type | description |
| RRAB | Variables of the RR Lyrae type, which are radially-pulsating giant A-F stars having amplitudes from 0.2 to 2 mag in V. Cases of variable light-curve shapes as well as variable periods are known. If these changes are periodic, they are called the "Blazhko effect." Traditionally, RR Lyrae stars are sometimes called short-period Cepheids or cluster-type variables. The majority of these stars belong to the spherical component of the Galaxy; they are present, sometimes in large numbers, in some globular clusters, where they are known as pulsating horizontal-branch stars. Like Cepheids, maximum expansion velocities of surface layers for these stars practically coincide with maximum light. RR(B) RR Lyrae variables showing two simultaneously operating pulsation modes, the fundamental tone with the period P0 and the first overtone, P1 (AQ Leo). The ratio P1/P0 is approximately 0.745; RRAB RR Lyrae variables with asymmetric light curves (steep ascending branches), periods from 0.3 to 1.2 days, and amplitudes from 0.5 to 2 mag in V; RRC RR Lyrae variables with nearly symmetric, sometimes sinusoidal, light curves, periods from 0.2 to 0.5 days, and amplitudes not greater than 0.8 mag in V (SX UMa). |