ESO VLT Spectropolarimetry of AT 2016adj in NGC 5128 (Centaurus A)
ATel #8668; Yi Yang (TAMU/Mitchell Institute), Lifan Wang (TAMU/Mitchell Institute), D. Baade (ESO), Peter J. Brown (TAMU/Mitchell Institute), A. Clocchiatti (PUC), P. Hoeflich (FSU), J. Maund (QUB), F. Patat (ESO), E. Reilly (QUB), J. Spyromilio (ESO), J. C. Wheeler (Texas University - Austin), and P. Zelaya (PUC)
on 10 Feb 2016; 20:40 UT
Credential Certification: Yi Yang (firstname.lastname@example.org)
Subjects: Optical, Supernovae, Transient
We report here the first spectropolarimetric observations of AT 2016adj (Atel #8651; discovered by BOSS) at 2016-02-09.25UT with the FORS2 instrument on the ESO VLT Unit Telescope 1 (Antu). We used grisms300V+10 and obtained polarized spectrum in the range 350 nm to 930 nm, with resolution ~11.8 Ã
at 6000 Ã
The flux spectrum confirms the heavy reddening reported in Atel #8654, #8655, #8657, #8662, #8664, and #8665. We also confirmed the H-alpha emission line reported in Atel #8655, #8657, and #8664, and CaII H&K lines reported in Atel #8657. Discernible NaID lines and DIBs (around 620.4 nm, 620.6 nm, and 628.4 nm) are also shown in the flux spectrum.
A preliminary analysis of the data shows a strong polarization, reaching 9.8% in the blue and decreasing to about 3.5% in the red. We consider the majority of the polarization is due to the inter-stellar medium. A Serkowski's law fit gives peak polarization of 9.8% and the wavelength at which the polarization peaks of 450 nm.