Comparison stars

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Light curve: Outburst in spring 2017

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Notes

3C 279 is a high polarization quasar (HPQ) and one of the most violent variable sources in the sky. It is a strong and violent variable from radio to gamma-rays. This OVV is very active with a total range of about 7 magnitudes (!) in the optical. The optical events show fast, spike-like flares with sharply raising and falling fluxes. 3C 279 was the first quasar detected at energies of >1 GeV with EGRET/CGRO. As a bright gamma source it was, of course, also detected by FERMI. High resolution imagery of 3C 279 showed a core-jet structure with a jet extending out to 10" to the SE. All this activity is produced by a supermassive black hole of about 1×109 solar masses. The designation 3C 279 refers to the 3rd Cambridge Radio Survey (3C), where this object was discovered as a radio source in 1959. Its optical counterpart was identified with a faint v=17.75 "blue, starlike object", which was immediately classified as a quasar by spectroscopy (with some similarities of BL Lac-like objects). For both visual and CCD observers, 3C 279 is an interesting target at any time. During the short outbursts, visual observers with telescopes of 8- to 10-inch of aperture may have no difficulties to track down this quasar. Visually, 3C 279 remains a stellar object even with large aperture telescopes. In the past 20 years, the Frankfurt Quasar Monitoring programme has recorded optical outbursts reaching maxima between mag 12.9 and mag 14.7. CCD observers, as well as visual observers, may use the comparison stars given above. Other photometric sequences were published by Doroshenko et al. (2005), Gonzàlez-Pérez et al. (2001) and the BAAVSS. ____________ Visual observers may also like to visit close double star Struve 690 (STF) = ADS 8707, only 1° to the north of 3C 279. It consists of a 7.2-mag primary and an 8.9-mag secondary, separated by 5.7 arcsec. For deep sky observers the near vicinity of 3C 279 offers two bright and large galaxies, both members of the Virgo galaxy cluster: NGC 4697 is a 10.1-mag elliptical, 1.9° W of 3C 279. NGC 4731, only 1.4° to the SW, is a distorted barred spiral due to gravitational interaction with elliptical NGC 4697. You like another deep sky showpiece? Sweep your telescope some 7° to the SW and you will meet M104, the famous "Sombrero Galaxy". Stargazers who prefer to observe more very old quasi-stellar photons are advised to turn their scopes to the most famous quasar of all: quasar "superstar" 3C 273, located some 10° NW of 3C 279. 3C 273 is an exceptionally bright 13-mag object at a distance of nearly 2×109 light-years. Another variable 15-mag quasar, PKS 1302-102, can be found about 5.3° SE.

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Literature

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Links: Landessternwarte Heidelberg Hamburg Quasar Monitoring Chara/PEGA BAAVSS AAVSO AAVSO observing campaign

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© Stefan Karge (FQM)  /  last obs. 2024-04-02

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