Mesarthim

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

note (category: star names):

Mesarthim; Mesartim; "First Star in Aries".

position, motion, parallax:

position (J2000)	RA: 1h 53min 31.8sec	DEC: +19° 17' 37''
position (B1900)	RA: 1h 48min 2.4sec	DEC: +18° 48' 13''
proper motion (J2000)	RA: 0.079 arcsec/a	DEC: -0.104 arcsec/a
radial velocity	-1 km/s note: variable radial velocity
rotational velocity	63 km/s (uncertain) (variable)
trigonometric parallax	0.026 arcsec
galactic coordinates	longitude: 142.55°	latitude: -41.2°

note (category: dynamical parallaxes):

0.019".

magnitude

visual magnitude

4.75
(original HR magnitude)

spectral / color information

spectral class	A1pSi
B-V-magnitude	-0.04
U-B-magnitude	-0.13
R-I-magnitude

note (category: spectra):

Also classified A0pCr, A1pCrSiSr.

variability information

variable star identification

Gam Ari

note (category: variability):

Alpha CV 3.88 - 3.90V, 2.6095 or 1.7982d; also possibly 2.5 hrs., amp. 0.02, unconfirmed. Southern component of ADS 1507. Magnetic var.

double/multiple star system information

number of components of multiple star system	3
separation	7.8 arcsec
mag difference (of double or brightest multiple)	0.1
component ID	AB

note (category: double and multiple data):

Binary with HR 545, orbital period 5000 - 10000y? Component C, 9.6v at 221". Combined colors for HR 545-6; combined mag. 3.88V.

miscellaneous information

note (category: group membership):

Pleiades group.

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

position, motion, parallax:

position (J2000)	RA: 1h 53min 31.825sec	DEC: +19° 17' 37.21''	ą1.24 arcsec	source: 29
proper motion (J2000)	RA: 0.0056 arcsec/a	DEC: -0.104 arcsec/a		source: 25
radial velocity	-1 km/s			source: 25
trigonometric parallax	0.026 arcsec		ą0.003 arcsec	source: 25
galactic coord. (B1950)	longitude: 142.56°	latitude: -41.2°

magnitude:

visual	4.75 (observed)	source: 51
photovisual	4.8	source: 2
photographic	4.8	source: 2

spectral information:

Morgan-Keenan	A1pSi		source: 25
B-magnitude	4.71 ą0.05	B-V-magnitude	-0.04
U-magnitude	4.58 ą0.05	U-B-magnitude	-0.13

variability information:

source of data: 27

variability type	160
var. amplitude	0
var. period	2.61
var. epoch	2440998.99 16. February 1971, 11:45:36 UT
next max light	2452219.38 5. November 2001, 21:07:12 UT

double/multiple star system information:

source of data: 19

separation between brightest and second brightest component	7.5 arcsec
magnitude difference between brightest and second brightest component	0
position angle	0 °

component	magnitude	spectral class	catalogue(s)/name(s)
A	4.75	-	Mesarthim, g²Arietis, 5 Ari, HR 546, HD 11502, SAO 92681
B	4.83	A0	g¹Arietis, 5 Ari, HR 545, HD 11503, SAO 92680

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
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
27	Catalog of Red Magnitudes (CRM)
Warren, W.H. Jr., Northern Hemisphere Catalog of Red Magnitudes, 1994
29	SAOJ2000
SAO on FK5 at J2000, 1989
51	Harvard photometry
"H" coded (Harvard photometry) magnitudes from the BSC5.

data from Smithsonian Astrophysical Observatory Star Catalog (SAO Staff 1966; USNO, ADC 1990)

position and proper motion:

position (B1950)	RA: 1h 50min 46.872sec	DEC: +19° 2' 57.87''	ą0.014 arcsec
position (J2000)	RA: 1h 53min 31.825sec	DEC: +19° 17' 37.21''
proper motion B1950 (FK4)	RA: 0.0056 arcsec/a	DEC: -0.1 arcsec/a	ą0.002 arcsec/a in RA ą0.002 arcsec/a in DEC
proper motion J2000 (FK5)	RA: 0.0056 arcsec/a	DEC: -0.104 arcsec/a
source of proper motion data	Determined by source catalog

magnitude:

visual	4.8 (accuracy: 2 decimals)
source of visual magnitude data	Taken from Harvard or San Luis photometry.

spectral information:

spectral class	A0p
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: 2291
Durchmusterung	BD+18 243A
Boss General Catalogue	2291
Henry Draper Catalogue	11503

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

position and proper motion:

position (J2000)	RA: 1h 53.5min	DEC: +19° 18'
proper motion (J2000)	RA: 0.081 arcsec/a	DEC: -0.108 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
AB	1821	often	358°	8.6''	4.8	4.8	A1pSi B9V	STF 180
	1988		0°	7.5''
AC	1823	8	85°	228.8''	4.8	9.6	-	STF 180
	1924		84°	221.3''

discoverer information:

discoverer code	discoverer	reference
STF 180	Struve, F.G.W.	-

notes:

note	Gamma Ari. A is a variable of the Alpha CVn type. Proper motion of B +077 -115.

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

position:

position (equinox 1950.0)

RA: 1h 50min 46.9sec

DEC: +19° 2' 58''

variability informations:

variability type	ACV	rotating variable star
magnitute at max. brightness	4.62
magnitute amplitude	0.04
photometric system	visual, photovisual or Johnson's V
epoch for maximum light [JD]	2440998.99 16. February 1971, 11:45:36 UT
period [d]	2.6095
next maximum light [JD]	2452219.84 6. November 2001, 08:09:36 UT
rising time	50 % of period

spectral information

spectral class

A1p(Cr-Si-Sr)

references

to a study	Vol. I GCVS (see Kholopov et al. 1985-1988)
to a chart/photograph	no chart is avaible, but the star is contained in the 'Bonner Durchmusterung'

miscanellous

ID in the GCVS catalogue	7/9003
constellation	Aries
notes on existence	The star is equivalent to '0080001 R'.
There are notes in published catalog.

variability type description

variability type

description

ACV

Alpha2 Canum Venaticorum variables. These are main-sequence stars with spectral types B8p-A7p and displaying strong magnetic fields.
Spectra show abnormally strong lines of Si, Sr, Cr, and rare earths whose intensities vary with rotation. They exhibit magnetic field and brightness changes (periods of 0.5-160 days or more). The amplitudes of the brightness changes are usually withine 0.01-0.1 mag in V.

ACVO
Rapidly oscillating Alpha2 CVn variables. These are nonradially pulsating, rotating magnetic variables of Ap spectral type (DO Eri). Pulsation periods are in the range of 6-12 mmag (0.004-0.01 days), while amplitudes of light variation caused by the pulsation are about 0.01 mag in V. The pulsational variations are superposed on those caused by rotation.

catalogues and names	Mesarthim, g²Ari, gam Ari, 5 Ari, HR 546, HD 11502, SAO 92681, BD +18 243 B, WDS 01535+1918A
other names	Mesartim, First Star in Aries
constellation	Aries