Continuing observations of KT Eri by Swift
ATel #17141; K. L. Page (U. Leicester)
on 10 Apr 2025; 15:10 UT
Credential Certification: Kim Page (kpa@star.le.ac.uk)
Subjects: Ultra-Violet, X-ray, Nova
Further observations of KT Eri (Nova Eri 2009) have been obtained by
the Neil Gehrels Swift Observatory, following the increase in optical
brightness announced in ATel #17125. As reported by Masetti &
Munari in ATel #17140, an observation with the X-ray Telescope (XRT)
on 2025 April 6 did not detect an X-ray source, to a 3σ upper
limit of 5 x 10-3 count s-1 (0.3-10 keV).
Observations on April 8 and 10, however, both revealed a faint X-ray
source at > 3σ significance, with a mean count rate of (4.2
+1.1/-0.9) x 10-3 count s-1. There is no
evidence of variation in the count rate between the two
observations. While there are too few counts to perform a detailed
spectral fit, it is clear that the emission is not super-soft.
Data collected by the UV/Optical Telescope show the UV emission to be
increasing, rising from w2 = 13.05 +/- 0.02 to 12.75 +/- 0.03 mag (Vega system) between
April 6 and 10.
Continuing observations with Swift are planned until KT Eri enters the
solar observing constraint on 22nd April.
