English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

We present and discuss highly accurate photometry obtained through mediumStromgren y,b bands and narrow [OIII], Halpha bands covering 500 days of theevolution of Nova Del 2013 since its maximum brightness. This is by far themost complete study of any nova observed in such photometric systems. The novabehaviour in these photometric bands is very different from that observed withthe more conventional broad bands like UBVRI or ugriz, providing uniqueinformation about extent and ionization of the ejecta, the onset of criticalphases like the transition between optically thick and thin conditions, andre-ionization by the central super-soft X-ray source. The actual transmissionprofiles of the y, b, [OIII] and Halpha photometric filters have beenaccurately measured at different epochs and different illumination angles, toevaluate in detail their performance under exact operating conditions. Theextreme smoothness of both the Halpha and [OIII] lightcurves argues for absenceof large and abrupt discontinuities in the ejecta of Nova Del 2013. Should theyexist, glitches in the lightcurves would have appeared when the ionizationand/or recombination fronts overtook them. During the period of recorded verylarge variability (up to 100x over a single day) in the super-soft X-rayemission (from day +69 to +86 past V maximum), no glitch in excess of 1% wasobserved in the optical photometry, either in the continuum (Stromgren y) or inthe lines ([OIII] and Halpha filters), or in a combination of the two(Stromgren b, Johnson B and V). Considering that the recombination time scalein the ejecta was one week at that time, this excludes global changes of thewhite dwarf as the source of the X-ray variability and supports instead clumpyejecta passing through the line of sight to us as its origin.

500 days of Stromgren b, y and narrow-band [OIII], Ha photometric evolution of gamma-ray Nova Del 2013 (= V339 Del)