Optical Flaring in Two Blazars Detected by CRTS
ATel #2145; S. G. Djorgovski, A. A. Mahabal, A. J. Drake, M. J. Graham, R. Williams (Caltech); E. C. Beshore, S. M. Larson (LPL/UA); E. Christensen (Gemini Observatory);
on 4 Aug 2009; 06:47 UT
Credential Certification: S. George Djorgovski (george@astro.caltech.edu)
Subjects: Optical, AGN, Quasar
We report optical flaring of two blazars, detected by the CRTS, on 31 July 2009 UT:
CSS090731:143854+371035 = CGRaBS/CRATES J143853+371026 has been observed at ~ 17.4 mag by CRTS. The source has brightened by ~ 1 mag over the past 2 months, and by ~ 2 mag since the end of January. SDSS gives the magnitudes u = 22.7, g = 21.4, r = 21.5, i = 21.4 and z = 21.2. Follow-up observations at the Palomar 60-inch telescope give magnitudes: g = 17.7, r = 17.3, i = 17.0, and z = 16.5, uncertain by ~ 0.1 mag, on 01 Aug 2009 UT; and g = 17.9, r = 17.4, i = 17.2, and z = 16.55, uncertain by ~ 0.1 mag, on 02 Aug 2009 UT, i.e, ~ 4 mag brighter than the SDSS values. A spectrum obtained at the Palomar 200-inch telescope on 01 August 2009 UT shows a strong blue continuum, with a probable Ly-alpha 1216 and N V 1240 emission lines, and the Ly-alpha forest, corresponding to the redshift z = 2.39.
CSS090731:230734+145017 = CGRaBS/CRATES J230733+145026 has been observed at ~ 17.9 mag by CRTS. The source has generally brightened by ~ 2 mag over the past ~ 1.5 years, but with a strong variability by up to ~ 2 mag over time intervals of ~ 2 months. SDSS gives the magnitudes u = 21.7, g = 21.0, r = 20.1, i = 19.55 and z = 19.1. Follow-up observations at the Palomar 60-inch telescope give magnitudes: g = 19.3, r = 18.4, i = 17.8, and z = 17.2, uncertain by ~ 0.1 mag, on 01 Aug 2009 UT; and g = 19.2, r = 18.45, i = 17.95, and z = 17.1, uncertain by ~ 0.1 mag, on 02 Aug 2009 UT, i.e, ~ 2 mag brighter than the SDSS values. The source has a known redshift in NED, z = 0.503.
Links to the finding charts, light curves, and other data are available at: http://nesssi.cacr.caltech.edu/catalina/AllBlaz.html#table1
Catalina Real-Time Transient Survey
