[vsnet-alert 13277] (fwd) First Detection of T Pyx in the Radio

[Taichi Kato]

   T Pyx has been first detected in the radio.  This detection appears
to be related to the recent increase of brightness and appearance of
Fe II lines.

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ATEL #3318							     ATEL #3318

Title:	First Detection of T Pyx in the Radio
Author:	L. Chomiuk (CfA/NRAO), M. I. Krauss (NRAO), J. L. Sokoloski
		(Columbia U.), M. P. Rupen, A. J. Mioduszewski, N. Roy (NRAO), T.
		J. O'Brien (U. of Manchester), M. F. Bode (Liverpool John Moores U.),
		S. P. S. Eyres (U. of Central Lancashire)
Queries:	lchomiuk at cfa.harvard.edu
Posted:	2 May 2011; 18:15 UT
Subjects:Radio, Cataclysmic Variable, Nova

We report an EVLA radio continuum detection of the recurrent nova T Pyx,
which was discovered to be in outburst on 2011 April 14 (CBET #2700, IAUC
#9205). The EVLA detected T Pyx on May 1.1 at 33.1 GHz with a flux density
of 248 +/- 32 microJy. One week earlier, on April 22.9, we measured a flux
density of 16 +/- 30 microJy at this frequency, which we take to be a non-detection.</br>

In addition, we observed T Pyx at 5.9 GHz on both dates, but it was not
detected in either epoch, consistent with ATel #3310. The formal 5.9-GHz
flux densities are 3.1 +/- 8.0 microJy on April 22.0 and 27 +/- 11 microJy
on April 30.9.</br> 

On May 1.1, T Pyx had a spectral index (S<sub>&nu</sub> &prop &nu<sup>&alpha</sup>)
of &alpha > 1.2, consistent with the optically-thick thermal emission expected
from the early stages of expanding nova ejecta. Assuming T Pyx is optically
thick with a brightness temperature of 10^4 K and expanding with spherical
symmetry and a velocity of 1800 km/s (IAUC #9205), our 33.1 GHz measurement
implies a distance of 5.5 kpc.</br> 

We plan to continue monitoring T Pyx with the EVLA, and will post updated
results on our <a href="https://safe.nrao.edu/evla/nova/">EVLA nova webpage</a>.</br>

The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated Universities,
Inc. We are grateful to the EVLA commissioning team.</br> 

EVLA Nova Webpage: https://safe.nrao.edu/evla/nova
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Password Certification: Laura Chomiuk (lchomiuk at cfa.harvard.edu)
http://www.astronomerstelegram.org/?read=3318
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