Frankfurt Quasar Monitoring

PKS 0422+00
Object data

  Cross-Identifications   OF+038, OF 038, PKS 0422+004, PKS B0422+004
  TXS 0422+004, GC 0422+004, QSO B0422+004
  RGB J0424+006, VSOP J0424+0036, 0422+004
  2MASS J04244684+0036062, 1E 0422.1+0029
  87GB 042213.1+002922, MG1 J042447+0036
  1RXS J042446.8+003559, QSO J0424+0036
  Equat. coordinates   RA  04 24 46.8     DE  +00 36 07     (J2000)
  Constellation   Taurus
  Type   BL Lac
  Redshift (2)   z=0.310
  Distance (2) (3)
  1188 Mpc
  Total mag range (mv) (4)   13.65 - 17.0
  Catalog Magnitude (1)   16.98
  Absolute Magnitude (1)   --- MB
  Light Travel-Time (2)   3.385 × 109 yrs
(1) Véron-Cetty & Véron 2006, A&A 455, 776
(2) NASA/IPAC Extragalactic Database
(3) Co-Moving Radial Distance
(4) Literature

Finding chart


Comparison stars

star  B V
A 13.19 12.51
B 14.58 13.96
C 15.45 14.75
D 15.70 15.05
comparison stars from Miller et al. 1983, AJ, 88, 1301

Light curve


PKS 0422+00 is a violently variable BL Lac object in southern Taurus, close to the constellations Eridanus and Orion. The designation PKS 0422+00 refers to Parkes Radio Survey (PKS), where this object was discovered as a radio source in 1966. Today, PKS 0422+00 is classified as a BL Lac object, due to its featureless spectrum. Despite that, a redshift of z=0.310 was reported by Smith & Nair (1995). For PKS:0422+00, a redshift of z=0.310 means a distance of about 3×109 light-years. On the other hand, this redshift is not fully accepted (not listed in the quasar catalogs of Véron-Cetty & Véron 1998-2006). In addition, a new redshift of z=0.476 was published by Agudo et al. (2010). So, further research will tell about the true distance of this Blazar.

As for most BL Lac objects, also this source
has been recognized as a violently variable in the optical - in this case by more than 3 magnitudes, ranging between mag 13.65 and mag 17.0.
Visual observers with a telescope of 8- to 10-inch of aperture will need a little luck to track down this blazar visually, as it is only visible during bright state. During fainter state, larger aperture is required to be successful. In case PKS 0422+00 is visible, the sequence above will help to estimate the apparent
brightness. But primarily,
the sequence will be useful for CCD observers for photometric reduction. Another photometric sequence was published by Smith et al. (1998).

Observers who like to continue their observing session with more quasi-stellar photons may turn to another BL Lac object, MG 0509+0541, a bright and variable 15-mag object, some 12° ENE of PKS 0422+00. Heading some 13° to the SSW, observers will meet quasar PKS 0405-12, a bright 14-mag object at a distance of more than 5×109 light-years.

Adams, G. 1985, A&AS, 61, 225; UBV Photometry of Quasars and Quasar Candidates. II.
Agudo, I., Thum, C., Wiesemeyer, H., Krichbaum, T.P. 2010, ApJS, 189, 1; A 3.5 mm Polarimetric Survey of
     Radio-loud Active Galactic Nuclei.
Bolton, J.G., Shimmins, A.J., Merkelijn, J. 1968, AuJPh, 21, 81; Identification of Radio Sources between
     Declinations +27° and -30°.
Falomo, R., Scarpa, R., et al. 1994, ApJS, 93, 125; Optical Spectrophotometry of Blazars.
Falomo, R., Bersanelli, M., et al. 1993, AJ, 106, 11; The Optical to Near-Infrared Emission of BL Lac Objects:
     Simultaneous Observations.
Karge, S.; Helle Quasare für 8- bis 10-Zoll Teleskope. Ein Beobachtungsführer zur visuellen Beobachtung von
     Quasaren und BL Lacertae Objekten; Frankfurt 2005.
Katajainen, S., Takalo, L.O., et al. 2000, A&AS, 143, 357; Tuorla Quasar Monitoring. I. Observations of 1995-1997.
Kinman, T.D. 1976, IAU Circ., No. 2908; PKS 0422+004.
Margon, B., et al. 1985, ApJS, 59, 23; An Atlas of X-ray-selected Quasi-stellar Objects.
Miller, H.R., Mullikin, T.L., McGimsey, B.Q. 1983, AJ, 88, 1301; Photoelectric Comparison Sequences in the Fields
     of four BL Lacertae Objects.
Pica, A.J., Smith, A.G., Webb, J.R., et al. 1988, AJ, 96, 1215; Long-term Optical Behavior of 144 Compact
     Extragalactic Objects - 1969-1988.
Pica, A.J., Pollock, J., Smith, A., et al. 1980, AJ, 85, 1442; Long-term Optical Behavior of 114 Extragalactic Sources.
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     Classes of AGN.
Smith, P.S., Balonek, T.J. 1998, PASP, 110, 1164; Photometric Calibration of Stars in the Fields of Selected BL
     Lacertae Objects and Quasars.
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Steinicke, W.; Beobachtungsliste für helle Quasare; Umkirch 1999.
Véron-Cetty, M.-P., Véron, P. 2001, A&A 374, 92; A Catalogue of Quasars and Active Nuclei: 10th edition.
Véron-Cetty, M.-P., Véron, P. 2003, A&A 412, 399; A Catalogue of Quasars and Active Nuclei: 11th edition.
Véron-Cetty, M.-P., Véron, P. 2006, A&A 455, 776; A Catalogue of Quasars and Active Nuclei: 12th edition.
Véron-Cetty, M.-P., Véron, P. 2010, A&A 518, 10; A Catalogue of Quasars and Active Nuclei: 13th edition.
Wills, D., Wills, B.J. 1976, ApJS, 31, 143; Spectroscopy of 206 QSO Candidates and Radio Galaxies.
Wills, B.J., Wills, D. 1979, ApJS, 41, 689; Spectroscopy of 125 QSO Candidates and Radio Galaxies.
Xie, G.Z., Li, K.H., et al. 1990, A&A, 229, 329; Search for short Variability Time-scales of BL Lacertae Objects.
Xie, G.Z., Li, K.H., et al. 1992, ApJS, 80, 683; CCD Photometry of 14 BL Lacertae Objects and Theoretical Model.




© Stefan Karge (FQM)  /  last obs. 2024-03-05