R Hya


The object was found in the following catalogues:
  1. The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version)

  2. SKY2000 - Master Star Catalog

  3. Smithsonian Astrophysical Observatory Star Catalog

  4. The Washington Visual Double Star Catalog, 1996.0

  5. Combined General Catalogue of Variable Stars (Vol. I-III)


catalogues and names R Hya, HR 5080, HD 117287, SAO 181695, WDS 13297-2317

data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)


object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978)

position, motion, parallax:

position (J2000) RA: 13h 29min 42,8sec DEC: -23 16' 53''
position (J1900) RA: 13h 24min 14,8sec DEC: -22 45' 52''
proper motion (J2000) RA: -0,056 arcsec/a DEC: 0,016 arcsec/a
radial velocity -10 km/s
note: variable radial velocity

magnitude

visual magnitude 4,97
(V on UBV Johnson system)

spectral / color information

spectral class M7IIIe
B-V-magnitude 1,6
U-B-magnitude 0,68
R-I-magnitude 2,42
note (category: spectra): Technetium star. SiO maser emission. Also classified M6e-M9e.

variability information

variable star identification R Hya
note (category: variability): ADS 8920A, M 3.5 - 10.9v, 388.87d. Period varies; was 500d beginning of 18th century. M8 at minimum. Discovered by Montanari in 1670.

double/multiple star system information

separation 21,2 arcsec
mag difference (of double or brightest multiple) 8,5

miscellaneous information

note (category: group membership): Hyades group.
note (category: polarization): Polarization possibly due to circumstellar dust scattering.

data from SKY2000 - Master Star Catalog (Myers+ 1997)

position, motion, parallax:

position (J2000) RA: 13h 29min 42,791sec DEC: -23 16' 52,71'' 0,19 arcsec source: 16
proper motion (J2000) RA: -0,0041 arcsec/a DEC: 0,015 arcsec/a source: 25
radial velocity -10 km/s source: 25
galactic coord. (B1950) longitude: 314,23 latitude: 38,75
GCI unit vector (J2000) X: -0,849092 Y: -0,350461 Z: -0,395246

magnitude:

visual 4,97 (observed) source: 25
photovisual 5,9 source: 16

spectral information:

spectral class M0 source: 96
Morgan-Keenan M7IIIe source: 25
B-magnitude 6,57 0,05 B-V-magnitude 1,6
U-magnitude 7,25 0,05 U-B-magnitude 0,68

variability information:

source of data: 30
variability type 180
var. amplitude 7,4
var. period 388,87
var. epoch 2443596
28. March 1978, 12:00:00 UT
next max light 2451762,27
5. August 2000, 18:28:48 UT

double/multiple star system information:

source of data: 25
separation between brightest and second brightest component 21,2 arcsec
magnitude difference between brightest and second brightest component 8,5

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 (J1950) RA: 13h 26min 58,482sec DEC: -23 1' 24,51'' 0,023 arcsec
position (J2000) RA: 13h 29min 42,788sec DEC: -23 16' 52,57''
proper motion J1950 (FK4) RA: -0,0041 arcsec/a DEC: 0,011 arcsec/a 0,004 arcsec/a in RA
0,005 arcsec/a in DEC
proper motion J2000 (FK5) RA: -0,004 arcsec/a DEC: 0,016 arcsec/a
source of proper motion data Determined by source catalog

magnitude:

visual 3,5 (accuracy: 1 decimal)
source of visual magnitude data Source cited in source catalog introduction.

spectral information:

spectral class M7e
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: 18239
Durchmusterung BD-22 3601
Boss General Catalogue 18239
Henry Draper Catalogue 117287

data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)

position and proper motion:

position (J2000) RA: 13h 29,7min DEC: -23 17'
proper motion (J2000) RA: -0,055 arcsec/a DEC: 0,011 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
- 1891 7 324 21,2'' - 12 M7IIIe HO 381

discoverer information:

discoverer code discoverer reference
HO 381 Hough, G.W. -

notes:

note A is a Mira-type variable, R Hya. Physical pair.

data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)

position:

position (J1950) RA: 13h 26min 58,5sec DEC: -23 1' 25''

variability informations:

variability type M pulsating variable star
magnitute at max. brightness 3,5
magnitute at min. brightness 10,9
photometric system visual, photovisual or Johnson's V
epoch for maximum light [JD] 2443596
28. March 1978, 12:00:00 UT
period [d] 388,87
next maximum light [JD] 2451762,27
5. August 2000, 18:28:48 UT
rising time 49 % of period

spectral information

spectral class M6e-M9eS(Tc)

references

to a study the main characteristics of the star was determined by the authors themselves
to a chart/photograph Vol. I GCVS (see Kholopov et al. 1985-1988)

miscanellous

ID in the GCVS catalogue 42/1
constellation Hydra
notes on existence The star is equivalent to '0420002 S'.
There are notes in published catalog.

variability type description

variability type description
M Mira (Omicron) Ceti-type variables. These are long-period variable giants with characteristic late-type emission spectra (Me, Ce, Se) and light amplitudes from 2.5 to 11 mag in V. Their periodicity is well pronounced, and the periods lie in the range between 80 and 1000 days. Infrared amplitudes are usually less than in the visible and may be <2.5 mag. For example, in the K band they
usually do not exceed 0.9 mag. If the amplitudes exceed 1 - 1.5 mag , but it is not certain that the true light amplitude exceeds 2.5 mag, the symbol "M" is followed by a colon, or the star is attributed to the semiregular class with a colon following the symbol for that type (SR).