Recurrence of Radio Counterpart of V4641 Sgr (=XTE J1819-254)
ATel #61; R. M. Hjellming (NRAO)
on 18 Jul 2000; 15:23 UT
Distributed as an Instant Email Notice Request For Observations
Credential Certification: R.M. Hjellming (rhjellmi@nrao.edu)
Subjects: Radio, Request for Observations, Black Hole, Star, Transient
Referred to by ATel #: 62
On 2000 July 17.23 UT VLA 1-km array observations detected recurrence of radio emission
from V4641 Sgr (=XTE J1819-254) at a level of 1.6 mJy at 8.4 GHz. On July 18.13 UT it was
0.6, 0.9, 1.1, and 1.2 mJy at 1.49, 4.9, 8.4, and 14.9 GHz, corresponding to a spectrum of
~0.53*nuGHz^(-0.35) mJy. This is much weaker than the peak 400 mJy levels seen in its
September 1999 outburst (Hjellming et al. 2000, Ap.J., Nov. 10 issue), but indicates that
this superluminal jet source is undergoing recurrence of weak radio activity.
It was at levels below 0.4 mJy for several observations in the last year. Multiwavelength
observations are encouraged, but it is not known what levels are possible at other
wavelengths when it is in this weak radio state.
