H1821+643

Basic data :
7C 1821+6419 -- Seyfert 1 Galaxy Origin of the objects types : (Ref) Object type as listed in the reference "Ref" (acronym) Object type linked to the acronym according to the original reference () Anterior to 2007, before we can link the objet type to a reference, or given by the CDS team in some particular cases Other object types: X (2012ApJS,1AXG,...), QSO (2013ApJS,KODIAQ,...), IR (AKARI,IRAS,...), UV (KUV,PG,...), G (2012A&A,[SLK2004]), gam (IGR,INTREF), Rad (7C,8C), Sy1 (2012MNRAS), AGN (2010A&A), * (Gaia) Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" : ra dec : right ascension and declination (unit and frame defined according to your Output Options) Grey values are increasing the original precision due to the computation of frame transformations (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam) [error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue), position angle (in degrees North celestial pole to East) quality : flag of quality E ≥ 10" D : 1-10" (and some old data) C : 0.1-1" B : 0.01-0.1" + 2MASS, Tyc A : VLBI, Hipparcos bibcode : bibcode of the coordinates reference ICRS coord. (ep=J2000) : 18 21 57.2130271440 +64 20 36.221312076 (Optical) [ 0.0129 0.0140 90 ] A 2020yCat.1350....0G Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" : ra dec : right ascension and declination (unit and frame defined according to your Output Options) Grey values are increasing the original precision due to the computation of frame transformations (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam) [error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue), position angle (in degrees North celestial pole to East) quality : flag of quality E ≥ 10" D : 1-10" (and some old data) C : 0.1-1" B : 0.01-0.1" + 2MASS, Tyc A : VLBI, Hipparcos bibcode : bibcode of the coordinates reference FK4 coord. (ep=B1950 eq=1950) : 18 21 41.7952404312 +64 19 00.893856147 [ 0.0129 0.0140 90 ] Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" : ra dec : right ascension and declination (unit and frame defined according to your Output Options) Grey values are increasing the original precision due to the computation of frame transformations (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam) [error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue), position angle (in degrees North celestial pole to East) quality : flag of quality E ≥ 10" D : 1-10" (and some old data) C : 0.1-1" B : 0.01-0.1" + 2MASS, Tyc A : VLBI, Hipparcos bibcode : bibcode of the coordinates reference Gal coord. (ep=J2000) : 094.0024993850374 +27.4170503584680 [ 0.0129 0.0140 90 ] Syntax of proper motions is : "pm-ra pm-dec [error ellipse] quality bibcode" pm-ra : mu-ra*cos(dec) (expressed in the ICRS system in mas/yr) pm-dec : mu-dec (expressed in the ICRS system in mas/yr) [error ellipse] : error major axis and minor axis (in mas), orientation angle (in deg) quality : flag of quality (A=best quality -> E=worst quality, {� } =unknown quality) bibcode : bibcode of the proper motion reference Proper motions mas/yr : -0.006 0.004 [0.017 0.019 90] A 2020yCat.1350....0G Syntax of radial velocity (or/and redshift) is : "value [error] (wavelength) quality bibcode" value : radial velocity or/and redshift (Heliocentric frame) according to your Output Options (redshift may be not displayed if the data value is <0 and the database inside value is a radial velocity) [error] : error of the corresponding value displayed before (wavelength) : wavelength range of the measurement : Rad, mm, IR, Opt, UV, Xray, Gam or  '∼'(unknown) quality : flag of quality ( A=best quality -> E=worst quality, {� } =unknown quality) bibcode : bibcode of the value's origin Radial velocity / Redshift / cz : V(km/s) 76251 [90] / z(emission) 0.2970 [0.0003] / cz 89038 [90]    C 2013MNRAS.435.1233G Syntax of fluxes (or magnitudes) is : "filter-name (System) flux-value [error] quality MultVarFlags bibcode" filter-name : U, B, V, R, I, G, J, H, K, u, g, r, i, z (System) : may be AB (default is Vega) flux-value : value of flux or magnitude [error] : error value quality : flag of quality of the flux value ( A=best quality -> E=worst quality, {� } =unknown quality) MultVarFlags : Mult is zero or one char (J) for joined photometry ; Var can be zero or two chars (V[0-4]) bibcode : bibcode of the flux reference Fluxes (3) : B 14.23 [~] D 2010A&A...518A..10V V 14.24 [~] D 2010A&A...518A..10V G 13.882390 [0.002976] C 2020yCat.1350....0G	SIMBAD within arcmin ', {sourceSize:12, color:'#30a090'})); aladin.on('objectClicked', function(object) { var objName=object.data.MAIN_ID; aladin.showPopup(object.ra,object.dec,'',''+ objName+''); });" title="Show Simbad objects"> Overlay points in this preview 2MASS DSS SDSSXMMIRACIRISGALEX All (CDSPortal) Send to within arcsec The VizieR photometry tool allows for easy visualization of photometry points extracted around the Simbad position from photometry-enabled catalogues in VizieR. The search radius has to be specified by the user. It is currently limited to a maximum of 30 arcsec. It depends mostly on the precision or quality of the coordinates (SIMBAD and VizieR catalogs), the resolution of the images from which the sources were extracted, source extent, and source crowding. Suggestions are: crowded field: 0.5 to 1.5 arcsec, 3 arcsec otherwise; uncertain coordinates (SIMBAD quality E or coordinates without reference): 5 to 30 arsec (risky!).
Some important notes on this object about identifications and objects associations. notes: not to be confused with the cluster ClG 1821+64.

7C 1821+6419	IGR J18218+6421	QSO B1821+643	XSS J18196+6454
AKARI-FIS-V1 J1821561+642039	INTREF 900	QSO J1821+6420	[BAG2012] 275.5807+64.3694
AKARI-IRC-V1 J1821571+642036	IRAS 18216+6418	QSO B1821+642	[BDW2002] q1821+6419
1AXG J182200+6420	IRAS F18216+6419	RX J182155+64207	[HB93] 1821+643
7C 182140.90+641929.00	IRAS F18216+6419A	RX J1821.9+6420	[SLK2004] 1455
8C 1821+643A	IRAS 18216+6419	RX J1821.8+6419	[VV2000] J182157.2+642036
1E 1821+64.3	ISOSS J18218+6421	1RXS J182157.4+642051	[VV2003] J182157.2+642036
2E 4066	KODIAQ J182157+642036	SWIFT J1822.0+6421	[VV2006] J182157.2+642036
2E 1821.6+6419	KUV 18217+6419	SWIFT J1822.1+6421	[VV2010] J182157.2+642036
1ES 1821+64.3	PBC J1821.5+6421	SWIFT J1822.2+6420	[VV96] J182157.3+642036
EXO 1821.6+6419	PG 1821+643	UVQS J182157.22+642036.2	[VV98] J182157.2+642036
1H 1820+643	PSCz P18216+6418	WISEA J182157.22+642036.2	Gaia EDR3 2160562892865099392
H 1824+644	QSO B1821+6419	WISE J182157.22+642036.2
H 1821+643	QSO B1821+64	2XMMi J182157.2+642036

References (569 between 1850 and 2022) (Total 569) Simbad bibliographic survey began in 1850 for stars (at least bright stars) and in 1983 for all other objects (outside the solar system). Follow new references on this object

Collections of Measurements

External archives :

Archive data at HEASARC - High-Energy Astrophysics Science Archive Research Center

Data at NED - NASA/IPAC Extragalactic Database : H1821+643

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