Astronomy Archive

eROSITA’s first all-sky image

Posted June 26, 2020 By grigoris

Recently the first all-sky image of the X-ray sky was released by the eROSITA instrument on-board the Spectrum-Roentgen-Gamma” (SRG) mission. It is fascinating that they refer to a million X-ray, which is almost 10 times more than what has been discovered from all X-ray surveys so far, so a bright X-ray future lies ahead! The […]

Evolved Massive Stars at Low-metallicity II. Red Supergiant Stars in the Small Magellanic Cloud Ming Yang, Alceste Z. Bonanos, Bi-Wei Jiang, Jian Gao, Panagiotis Gavras, Grigoris Maravelias, Shu Wang, Xiao-Dian Chen, Frank Tramper, Yi Ren, Zoi T. Spetsieri, Meng-Yao Xue We present the most comprehensive RSG sample for the SMC up to now, including 1,239 […]

Packaging Skinakas’ primary mirror

Posted March 9, 2020 By grigoris

Back in November of 2019, the primary mirror (of 1.3m) at the Skinakas Observatory was dismounted to send it for recoating (a procedure performed once every 4-5 years). The following short clip shows the packaging of the mirror, a very delicate procedure (the whole process took several hours … compressed to a few minutes).

The second nearest exoplanet – Proxima c

Posted January 20, 2020 By grigoris

It is exciting to see that the nearest star to our Sun has more than one planet (Proxima b, [1]). In a paper led by Mario Damasso and Fabio Del Sordo [2] revealed the existence of another one. The Proxima c is a planet with an orbital period of about 1900 days (~5.21 years), a […]

New paper on evaluating outreach activities

Posted November 11, 2019 By grigoris

A short paper has been presented as a poster in the EPSC-DPS Joint Meeting 2019, held 15-20 September 2019 in Geneva, Switzerland. The data originate from a series of outreach activities performed by the Hellenic Amateur Astronomy Association, entitled “Introduction to Observational Astronomy“, which aimed to introduce interested individuals to the aspects of the observational […]

Conference contributions – summer 2019 edition

Posted November 8, 2019 By grigoris

Although the summer has finished long ago, only now I got some time to update on summer activities, i.e. a number of conferences I attended and contributed to. Since 2018, I have been working in an automated classifier for massive stars in nearby galaxies, using photometric datasets. These have been produced by my colleagues within […]

Master presentation by Elias Kyritsis

Posted September 30, 2019 By grigoris

Elias Kyritsis has been a student at the Physics Department of the University of Crete that I have co-supervised with Prof. Andreas Zezas since 2017. Initially as an undergraduate student he worked on the visual classification of High-Mass X-ray Binary sources in the Large Magellanic Cloud, but later on he decided to work on a […]

Evolved Massive Stars at Low-metallicity I. A Source Catalog for the Small Magellanic Cloud Ming Yang, Alceste Z. Bonanos, Bi-Wei Jiang, Jian Gao, Panagiotis Gavras, Grigoris Maravelias, Yi Ren, Shu Wang, Meng-Yao Xue, Frank Tramper, Zoi T. Spetsieri, Ektoras Pouliasis We present a clean, magnitude-limited (IRAC1 or WISE1 ≤ 15.0 mag) multiwavelength source catalog for […]

The ASSESS group roster 2019

Posted June 27, 2019 By grigoris

During the last four days I was busy with the actual materialization of the Astrostatistics Summer School Crete 2019, which took place at the University of Crete, in Heraklion (18-21 June 2019). My duties were mainly those of the Teaching Assistant and I contributed with a short presentation of the Random Forests method for classification. […]