View here: Details for Photometry in support of TESS and Swift Observations of common-envelope post-novae
Abstract: Dr. Frederick Walter (Stony Brook University) writes: We have identified two long-lived novae that remain bright more than a decade past their classical nova eruptions. These systems, V1280 Sco and V5856 Sgr, frequently fade from their “quiescent” levels, during which their optical spectra change from being dominated by cool emission lines to displaying spectral lines indicative of hot gas, most notably He II, C IV, and [Fe VII]. During TESS sectors 91-93 (April 9 - June 29 2025) we will observe these with in X-rays with SWIFT approximately weekly (simultaneously with the TESS photometry) to test the hypothesis that the fading is due to a thinning of a common envelope, permitting a view into a hot interior. We request BVRI CCD filter photometry during this time to look for color changes in the novae.
Justification: We request nightly BVRI CCD filter photometry (see below for instructions) to look for color changes in the targets. While TESS provides a superb cadence, it is a only single-channel photometer. Color variations as the systems fade will help us assess the physical cause of the fadings, and provide insights into nature of the systems. Note that the campaign begins April 1 and TESS coverage begins April 9; nightly coverage is requested to begin immediately.