Frankfurt Quasar Monitoring


S5 0716+71
Object data

  Cross-Identifications   TXS 0716+714, S5 0716+714, RGB J0721+713
  IRAS F07162+7126, 2MASS J07215342+7120362
  1RXS J072153.2+712031, WMAP J0721+7122
  GALEXASC J072153.36+712036.2, 0716+71
  87GB 071611.1+712619, GB6 J0721+7120
 
1WGA J0721.8+7120, 2EG J0720+7126
  RX J0721.8+7120, 1FGL J0721.9+7120
  8C 0716+714, 1H 0717+714, 2E 1802
  GEV J0719+7133, EGRET J0720+71
  Equat. coordinates   RA  07 21 53.3     DE  +71 20 36     (J2000)
  Constellation   Camelopardalis
  Type   BL Lac
  Redshift
  z=0.300 (2)  /  z=0.310 (5)
  Distance (2) (3)
  1153 Mpc
  Total mag range (mv) (4)    12.06 - 17.5
  Catalog Magnitude (1)   15.50
  Absolute Magnitude (1)   --- Mpc  
  Light Travel-Time (2)   3.299 × 109 yrs
(1) Véron-Cetty et al. 2006, ESO Scientific Report 22
(2) NASA/IPAC Extragalactic Database
(3) Co-Moving Radial Distance
(4) Literature
(5) Nilsson et al. (2008)

Finding chart
0716+714_chart_fqm.jpg

Comparison stars

star  B V Rc
1 12.02 (0.01)
11.46 (0.01)
11.12 (0.01)
2 13.04 (0.01)
12.43 (0.02)
12.06 (0.01)
3 13.66 (0.01) 13.19 (0.02)
12.89 (0.01)
4 14.15 (0.01)
13.55 (0.02)
13.18 (0.01)
5 14.24 (0.01)
13.63 (0.02)
13.26 (0.01)
6 14.55 (0.01) 13.74 (0.02)
13.32 (0.01)
7 14.70 (0.01)
14.10 (0.02)
13.79 (0.02)
8 15.685 (0.012)
15.025 (0.009) 14.654 (0.001)
9 16.097 (0.015)
15.550 (0.011)
15.087 (0.012)
10 16.621 (0.008)
16.028 (0.013)
15.653 (0.023)
comparison stars 1-7 from Villata et al. 1998, A&AS, 130, 305
comparison stars 8-10 from Gonzàlez-Pérez et al. 2001, AJ, 122, 2055

Colour chart
0716+714_color_fqm.jpg
Credit: DSS2  /  Size 14´x 14´ /  Chart by S. Karge

Light curve
0716+714_lc1605_fqm.jpg

Notes
S5 0716+71 is a bright and violently variable BL Lac object in Camelopardalis. Its position lies about 3.4° NE of star 43 Cam, and 2.2° N of irregular galaxy NGC 2366. S5 0716+71 was discovered as a radio source in 1977/78 during the 5 Ghz Strong Source Survey (S5). Follow-up spectroscopy clearly identified S5:0716+71 as a quasi-stellar object. Today, S5 0716+71 is classified as a BL Lac object due to its (nearly) featureless spectrum, rapid variability and strong optical polarization. The first accurate redshift measurement for S5 0716+71 was published in 2008. Besides the optical and radio, this blazar also has been kown as an emitter of infrared (IRAS), X-ray (1RXS, 1H) and even gamma (TeV) emissions (2EG, GEV, EGRET). The host galaxy itself has an apparent diameter of 5.4 arcsecs, which corresponds to a true size of only about 12 kpc.
Blazar S5 0716+71 is a violently variable object with a total optical range of more than 5 magnitudes! An exceptionally bright state in the optical was reported in January 2015, when the blazar reached 12.06 mv - the brightest magnitude for this object ever recorded.
On average, brightness varies between 13 mag and 14 mag. Due to its exceptional brightness, this blazar is an easy task for visual observers with telescopes of 8- to 10-inch of aperture, at maximum even for 6-inch telescopes. The object appears stellar even with large apertures. Without a go-to mount, tracking down blazar S5 
0716+71 may become a little tricky as it lies in a region lack of brighter stars for easy starhopping.
Both CCD observers and visual observers shall use the comparison stars given above. The comparison stars 4=13.55 and 5=13.63 are recommended for both unfiltered and v-mag photometry.
Another photometric sequence was published by Nesci et al. (2005).
Note: The data point of 12.27CV in the light curve above was CCD imaged by Manfred Mrotzek (Ger) on Jan. 17, 2015, 23:10UTC. Manfred kindly provided his images for photometric reduction, carried out by the author.
____________

When you are around for S5 0716+71, do not forget to visit the irregular galaxy NGC 2366 only 2.2° S, a low surface brightness galaxy and member of M 81-galaxy group.

Far beyond the M 81-galaxy group, and some 5° SW of S5 0716+71, another quasar is ready to be observed: HS 0624+6907. This is a bright 14-mag object at a distance of about 3.9×109 light-years.


Literature
Biermann, P., Duerbeck, H., et al. 1981, ApJ, 247, L53; Observations of six Flat Spectrum
     Sources from the 5 GHz Survey.
Gonzàlez-Pérez, J.N., et al. 2001, AJ, 122, 2055; Optical and Near-Infrared Calibration of
     AGN field stars: An All-Sky Network of faint stars calibrated on the Landolt System.
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.
Kühr, H., Johnston, K.J., et al. 1987, A&AS, 71, 493; Optical Identifications and Radio
     Morphology of the complete 5 Ghz S5 Survey.
Kühr, H., Pauliny-Toth, I.I.K., Witzel, A., Schmidt, J. 1981, AJ, 86, 854; The 5-Ghz Strong
     Source Survey. V. Survey of the area between Declinations 70° and 90°.
Nesci, R., Massaro, E., et al. 2005, AJ, 130, 1466; The long-term optical Variability of the
     BL Lacertae Object S5 0716+71: Evidence for a Precessing Jet.

Nilsson, K., Pursimo, T., et al. 2008, A&A, 487, L29; Detection of the host galaxy of
     S5 0716+714.
Raiteri, C.M, Villata, M., et al. 2003, A&A, 402, 151; Optical and Radio Behaviour of the BL
     Lacertae O
bject 0716+714.
Rector, T.A., Stocke, J.T. 2001, AJ, 122, 565; The Properties of the Radio-Selected 1 Jy
     Sample of
BL Lacertae Objects.
Steinicke, W.; Beobachtungsliste für helle Quasare; Umkirch 1999.
Véron-Cetty, M.-P., Véron, P.; A Catalogue of Quasars and Active Nuclei (10th Edition),
     ESO Scientific Report 20, ESO, Garching 2001.
Véron-Cetty, M.-P., Véron, P.; A Catalogue of Quasars and Active Nuclei (11th Edition),
     ESO Scientific Report 21, ESO, Garching 2003.
Véron-Cetty, M.-P., Véron, P.; A Catalogue of Quasars and Active Nuclei (12th Edition),
     ESO Scientific Report 22, ESO, Garching 2006.
Villata, M., Raiteri, C.M., et al. 1998, A&AS, 130, 305; BVR Photometry of Comparison Stars
     in selected B
lazar Fields, I: Photometric Sequences for 10 BL Lacertae Objects.
Wenzel, K. 2003, SuW 2/03, 60; BL-Lacertae-Objekte.
Wenzel, K. 2005, Interstellarum 38, 54; BL Lacertae-Objekte. Eine visuelle Langzeit-
     Überwachung.

Witzel, A., Schalinski, C.J., et al. 1988, A&A, 206, 245; The Occurrence of Bulk Relativistic
     Motion in
Compact Radio Sources.




Links:

Landessternwarte Heidelberg

SCAE Group (1)

SCAE Group (2)

Hamburg Quasar Monitoring

Chara/PEGA

GASP

Gary Poyner (light curve)

ATel #6953 / ATel #6962  (Optical Max. in 1/2015)


AAVSO
 

© 2016-05-05 by Stefan Karge







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