HT Lacertae

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

position, motion, parallax:

position (J2000)	RA: 22h 5min 16.4sec	DEC: +46° 44' 41''
position (B1900)	RA: 22h 1min 18sec	DEC: +46° 15' 33''
proper motion (J2000)	RA: -0.042 arcsec/a	DEC: -0.02 arcsec/a
radial velocity	-13 km/s
galactic coordinates	longitude: 95.68°	latitude: -7.14°

magnitude

visual magnitude

6.13
(V on UBV Johnson system)

spectral / color information

spectral class	M4IIIab
B-V-magnitude	1.61
U-B-magnitude	1.76
R-I-magnitude
IR-note	object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978)

variability information

variable star identification

HT Lac

note (category: variability):

SRb 6.08 - 6.36V, 82:d.

miscellaneous information

note (category: group membership):

NGC 7209 #86.

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

position, motion, parallax:

position (J2000)	RA: 22h 5min 16.56sec	DEC: +46° 44' 41.6''	ą0.43 arcsec	source: 16
proper motion (J2000)	RA: -0.0021 arcsec/a	DEC: -0.022 arcsec/a		source: 25
radial velocity	-13 km/s			source: 25
galactic coord. (B1950)	longitude: 95.68°	latitude: -7.14°

magnitude:

visual	6.1 (observed)	source: 31
photovisual	6.3	source: 2
photographic	7.3	source: 16

spectral information:

spectral class	M0		source: 96
Morgan-Keenan	M4IIIab		source: 25
B-magnitude	7.74 ą0.05	B-V-magnitude	1.61
U-magnitude	9.5 ą0.05	U-B-magnitude	1.76

variability information:

source of data: 30

variability type	194
var. amplitude	0.28
var. period	82

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
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
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 (B1950)	RA: 22h 3min 17.016sec	DEC: +46° 30' 5.27''	ą0.033 arcsec
position (J2000)	RA: 22h 5min 16.385sec	DEC: +46° 44' 41.26''
proper motion B1950 (FK4)	RA: -0.0043 arcsec/a	DEC: -0.016 arcsec/a	ą0.007 arcsec/a in RA ą0.005 arcsec/a in DEC
proper motion J2000 (FK5)	RA: -0.0041 arcsec/a	DEC: -0.02 arcsec/a
source of proper motion data	Determined by source catalog

magnitude:

visual	6.3 (accuracy: 2 decimals)
source of visual magnitude data	Taken from Harvard or San Luis photometry.

spectral information:

spectral class	Mb
source of spectral data	Taken from the Henry Draper Catalogue or no spectrum in source catalog.

catalogues

source catalogue	GC, catalogue number: 30898
Durchmusterung	BD+46 3574
Boss General Catalogue	30898
Henry Draper Catalogue	209857

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

position:

position (equinox 1950.0)

RA: 22h 3min 17sec

DEC: +46° 30' 5''

variability informations:

variability type	SRB	pulsating variable star
magnitute at max. brightness	6.08
magnitute at min. brightness	6.36
photometric system	visual, photovisual or Johnson's V
period [d]	82 (uncertain)

spectral information

spectral class

M4IIIab

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	45/220
constellation	Lacerta
notes on existence	The star is equivalent to '0450221 HU'.
There are notes in published catalog.

variability type description

variability type

description

SRB

Semiregular variables, which are giants or supergiants of intermediate and late spectral types showing noticeable periodicity in their light changes, accompanied or sometimes interrupted by various irregularities. Periods lie in the range from 20 to >2000 days, while the shapes of the light curves are rather different and variable, and the amplitudes may be from several hundredths to several magnitudes (usually 1-2 mag in V).

SRA
Semiregular late-type (M, C, S or Me, Ce, Se) giants displaying persistent periodicity and usually small (<2.5 mag in V) light amplitudes (Z Aqr). Amplitudes and light-curve shapes generally vary and periods are in the range of 35-1200 days. Many of these stars differ from Miras only by showing smaller light amplitudes;

SRB
Semiregular late-type (M, C, S or Me, Ce, Se) giants with poorly defined periodicity (mean cycles in the range of 20 to 2300 days) or with alternating intervals of periodic and slow irregular changes, and even with light constancy intervals (RR CrB, AF Cyg). Every star of this type may usually be assigned a certain mean period (cycle), which is the value given in the Catalogue. In a number of cases, the simultaneous presence of two or more periods of light variation is observed;

SRC
Semiregular late-type (M, C, S or Me, Ce, Se) supergiants (Mu Cep) with amplitudes of about 1 mag and periods of light variation from 30 days to several thousand days;

SRD
Semiregular variable giants and supergiants of F, G, or K spectral types, sometimes with emission lines in their spectra. Amplitudes of light variation are in the range from 0.1 to 4 mag, and the range of periods is from 30 to 1100 days (SX Her, SV UMa).