Nova Del 2013 (V339 Del) is now a bright super-soft X-ray source
ATel #5505; Julian P Osborne, Kim Page, Andrew Beardmore (University of Leicester), Chick Woodward (University of Minnesota), Greg Schwarz (AAS), Mike Bode (Liverpool JM University), Jan-Uwe Ness (ESAC), Steve Shore (University of Pisa, INFN-Pisa), Sumner Starrfield (ASU), Mark Wagner (OSU), Fred Walter (SUNY)
on 24 Oct 2013; 15:47 UT
Credential Certification: Julian P Osborne (firstname.lastname@example.org)
Regular Swift XRT monitoring of nova Del 2013 since our report in ATEL #5470 has revealed a decrease
in the high absorbing column affecting the optically thin harder X-ray emission above 1 keV; spectral fits suggest
N_H ~ 5x10^22 cm^-2 around day 45 and N_H ~ 1.8x10^22 around day 65 after discovery on Aug 14, 2013.
The super-soft X-ray source has been increasing in apparent brightness since it was first seen, the 0.3-1.0 keV grade 0 count rate is tabulated below
|UT Date ||Day since detection ||0.3-1 keV XRT count/s
|2013 Oct 13 ||60.2 ||0.0067 +0.0014/-0.0011
|2013 Oct 17 ||63.8 ||0.011 +/- 0.001
|2013 Oct 20-21 ||67.4 ||0.023 +/- 0.002
|2013 Oct 23 ||69.7 ||0.079 +/- 0.006
|2013 Oct 24 ||70.8 ||1.5 +/- 0.2
The increase in count rate is exclusively below 0.7 keV, suggesting the unveiling of the hot white
We note that the recent more-rapid SSS brightening since day 67 coincides with an apparent plateau in the AAVSO V
band light curve.
We thank the Swift PI and operations team for their support of these observations.