University of California, Davis, U.S.A.
Talks.
Early high-cadence observations of SNe: revealing features of variability and identifying their diversity + introduction to Supernovae Types
Technical University of Denmark, DTU
21 June 2019, Lyngby, Denmark
Emmanouela Paraskeva
IAASARS, National Observatory of Athens
Abstract
Supernovae are characterised by their long term photometric evolution over days and weeks. We introduced the Supernovae evolutionary stages and their Types. Due to the fact that there is growing evidence that these objects also exhibit short term variations over seconds, minutes and hours as in SN2014J, for which a previous pilot study (Bonanos & Boumis 2016) revealed signs of rapid variability, we observed 5 supernovae before and near the maximum light. The main results and the methods were presented in this talk. The aim of this research was to characterize their early light curves and investigate their behavior on short timescales.
Early high-cadence observations of SNe: revealing features of variability and identifying their diversity
FOE, North Carolina State University
20-24 May 2019, Raleigh, North Carolina, USA
Abstract
High-cadence photometry on the early evolutionary stage of supernova light curves has the potential to
provide a better understanding of nearly every aspect of SNe, from their explosion physics to their
progenitors and the circumstellar environment. Given the increasing rate of discovery of bright
supernovae before their maximum brightness from modern time-domain optical surveys, we have theopportunity to capture their intraday behaviour near the time of their explosions.
We presented results of monitoring the optical light curves of ~9 bright SNe, primarily using the 2.3m Aristarchos telescope and 1.2m Kryoneri telescope. The supernovae were observed over several nights during the early and
late evolution with a cadence of 30-120s and high precision differential aperture photometry was derived. Differential light curves with respect to all comparison stars available on each night, as well as reconstructed light curves after implementing the Trend Filtering Algorithm (TFA; Kovacs et al. 2005) are showed. We derived the decline slope of each supernova on each night and quantify the precision of our photometry and variability in the light curves, after accounting for sources of systematic error. We encourage further high-cadence photometric monitoring of bright SNe with the goal of identifying explosion mechanisms, binary-star interaction, progenitor channels, or properties of the explosion environment.
Gaia transient follow-up from the National Observatory of Athens
8th OPTICON Gaia Science Alerts workshop,
6 - 8 December 2017, Warsaw, Poland
Abstract
We introduced the telescopes that are coordinated from the National Observatory of Athens and were used to observe Gaia transients. Gaia Photometric Science Alerts ("Gaia Alerts") is an all-sky photometric transient survey, based on the repeated, high-precision measurements made by the Gaia satellite. These repeated scans are needed to make high precision measurements of stellar positions, but they are ideal to look for variations in brightness as well. Its goal is to coordinate ground-based observations on alerts triggered by the data processing system during the mission for the confirmation of newly detected moving objects or for the improvement of orbits of some critical targets.
High-cadence photometry of bright Type Ia Supernovae with the 2.3m Aristarchos telescope
13th Hellenic Astronomical Conference
2-6 July, 2017, Heraklion, Crete, Greece
Abstract
Rapid variability of every evolutionary stage of the light curves of supernovae has the potential to provide a better understanding of nearly every aspect of supernovae, from their explosion physics to their progenitors and the circumstellar environment. We emphasised our research in bright and not heavily contaminated by their host galaxy, SNe. We presented the observations with the 2.3 m Aristarchos telescope, the methods and the results of the high-cadence monitoring of 3 Type Ia SNe in the post-peak epoch with intraday observations that exceeded 500 frames.