University of California, Davis, U.S.A.
Observations
Below is an overview of observation programmes of which I have joined as PI, coI or support astronomer.
High cadence observations of Supernovae to reveal signs of variability in blue bands
Telescope/Instrument: Aristarchos/LN2 CCD
Program ID:
Time allocated:
Status: Completed, publication in preparation
Abstract
Supernovae are characterised by their long term photometric evolution over days and weeks. 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 propose to monitor 3-6 future bright supernovae with high cadence observations in the Summer 2018, which are being discovered in increasing numbers by current wide-field transient surveys. The study will target ideally both Type Ia and Type II supernovae several days before their maximum light. The aim of this proposal is to characterize their early light curves and investigate their behavior on short timescales. The supernovae will be selected from the list of latest supernovae, published online by www.rochesterastronomy.org and the Transient Name Server (TNS)
Gaia Transient follow up
Telescope/Instrument: Aristarchos/LN2 CCD
Program ID:
Time allocated:
Status: Completed, published
Abstract
Gaia16aye was a binary microlensing event discovered in the direction towards the northern Galactic disc and was one of the first microlensing events detected and alerted to by the Gaia space mission. Its light curve exhibited five distinct brightening episodes, reaching up to I=12 mag, and it was covered in great detail with almost 25,000 data points gathered by a network of telescopes. It is the first-ever detection of the microlensing space-parallax between the Earth and Gaia located at L2. The properties of the binary system were derived from microlensing parameters, and the system is composed of two main-sequence stars with masses 0.57±0.05 M⊙ and 0.36±0.03 M⊙ at 780 pc, with an orbital period of 2.88 years and an eccentricity of 0.30.
NELIOTA: Monitoring lunar impact flashes
Telescope/Instrument: Kryoneri/Andor Zyla
Program ID:
Time allocated:
Status: Completed, published
Abstract
NELIOTA is an activity launched by the European Space Agency (ESA) at the National Observatory of Athens in February, 2015. It will run until January 2021. It aims to determine the distribution and frequency of small near-earth objects (NEOs) by monitoring lunar impact flashes. The NELIOTA project has established an operational system that started monitoring the Moon for faint NEO impacts in early 2017, using the 1.2m Kryoneri telescope, located in the Northern Peloponnese, in Greece.
The Kryoneri telescope was upgraded for the project in 2016. Specialised fast-frame cameras were installed and specialised software was developed to control the telescope and cameras, as well as process the resulting images to detect the impacts automatically. NELIOTA furthermore provides a web-based user interface, where the impact events are reported and made available to the scientific community and the general public.
The 1.2m Kryoneri telescope is capable of detecting flashes much fainter than current, small-aperture, lunar monitoring telescopes. NELIOTA is therefore expected to characterize the frequency and distribution of NEOs weighing as little as a few grams.