Alladi Ramakrishnan Hall

V1331 Cyg - an outburst of results

Arpita Choudhary

Thuringer Landessternwarte Tautenburg, Tautenburg, Germany

With first epoch observations of HST-WFPC2 already available for V1331 Cyg, second epoch data was observed in 2009. Time evolution study of circumstellar nebula by analysing and comparing the two epochs suggests that the outer ring is expanding at approx. 11+/-2 km/sec. The expansion velocity of inner ring is less consistent, between 0.77 km/sec. and 3.326 km/sec. Radial color profiles do not hint on particle separation in those arcs. Additional data from other instruments - UKIDSS, SPITZER, SUBARU and TLS helped to improve the understanding of the young star in terms of viewing angle, bipolar outflow length, missing ring section and FUor phenomenon. HST planetary camera image reveals a knot like feature at 220 AU from the central source. Subaru image shows scattered light in the same direction as that of the knot. Missing ring section could be a result of shadowing due to presence of the knot. Viewing V1331 Cyg almost pole-on, the length of the bipolar outflow is updated to be 10 pc or even more.