Swift follow-up observations of the optical transient ASASSN-19vj
L. E. Rivera Sandoval & T. J. Maccarone (Texas Tech University)
We report on X-ray and UV follow-up observations of ASASSN-19vj (ATEL #13061), which was identified as an optical transient on the rise at 17.5 mag in g by the ASAS-SN on UT 2019-08-29.99.

We obtained 645s of Swift XRT/UVOT observations of the transient on 2019-09-05. The object was not identified in X-rays in the 0.3-10keV energy band.

We determined UVOT magnitudes in the following filters (all in Vega system):

V = 16.86 +/- 0.2 B = 17.06 +/- 0.11 U = 16.81 +/- 0.13 UVW1 = 18.12 +/- 0.26 UVW2 = 18.64 +/- 0.27 UVM2 > 19.28

Given its colors and slow rise time, the object does not seem to be consistent with a dwarf nova or a nova scenario. A young stellar object is not favored given its Galactic latitude. Archival images from the VISTA hemisphere survey suggest a limiting magnitude of around 21 in the region where ASASSN-19vj is located, which means that a faint galaxy hosting a SN could be present. Spectroscopic observations are encouraged.

We thank the Swift team for approving and scheduling our ToO request.
infra-red,optical,ultra-violet,x-ray,cataclysmic variable,nova,supernovae,transient,variables,young stellar object