maravelias.info

about Grigoris Maravelias

the basics

who am i?

Astrophysicist with a robust foundation in Physics and Engineering, complemented by proficient Data Science skills encompassing statistics and machine/deep learning applications.

current position

Since September 2018 I am working as a post-doc at the National Observatory of Athens (although you will finding me more in Heraklion, Crete), with Dr. Alceste Bonanos for the ASSESS project.

research interests

Observational Astrophysics focusing on stellar astrophysics and massive stars (phases, evolution), in different galaxies. Use of statistical tools and implementation of machine/deep learning approaches. Professional-amateur networking and collaborations, and Openness in Astronomy.

latest news

Traveling:

Currently I am back home. No travels arrangements in the near future!

Teaching:

Starting an internship project on missing values imputation.

Recent Publications:

Latest publications

New paper: Shenar et al. 2024: Binarity at LOw Metallicity (BLOeM): I. a spectroscopic VLT monitoring survey of massive stars in the SMC

This is the first paper of the "Binarity at LOw Metallicity (BLOeM)" collaboration which targets to obtain spectra for about 1000 massive stars in the...

New paper: de Wit et al. 2024: Investigating episodic mass loss in evolved massive stars: II. Physical properties of red supergiants at subsolar metallicity

Stephan extends the work he has performed previously in the Magellanic Clouds to RSGs identified in the ASSESS project in galaxies at subsolar metallicity. Investigating...

New paper: Establishing a mass-loss rate relation for red supergiants in the Large Magellanic Cloud

This is a paper led by Kostas from the ASSESS team where we investigated the mass-loss in LMC/s RSGs. Interestingly this made its way to...

New paper: X-Shooting ULLYSES: Massive Stars at low metallicity: II. DR1: Advanced optical data products for the Magellanic Clouds

Paper II of the XShootU collaboration is finally accepted at A&A! That is a cornerstone paper for the collaboration since it presents the analysis of...

New paper: Investigating episodic mass loss in evolved massive stars: I. Spectroscopy of dusty massive stars in ten southern galaxies

A paper that collectively presents the results from our intensive observing campaign in the ASSESS project, focusing on the southern galaxies (a forthcoming paper will...

New paper: Introducing the ASSESS project: Episodic Mass Loss in Evolved Massive Stars – Key to Understanding the Explosive Early Universe

This is the paper that describes the ASSESS project for which I have been working since 2018 ! Introducing the ASSESS project: Episodic Mass Loss...

blog

New paper: Shenar et al. 2024: Binarity at LOw Metallicity (BLOeM): I. a spectroscopic VLT monitoring survey of massive stars in the SMC

grigoris July 27, 2024 July 27, 2024

This is the first paper of the “Binarity at LOw Metallicity (BLOeM)” collaboration which targets to obtain spectra for about 1000 massive stars in the SMC! Apart from being an extremely interesting project it really matches many of the sources I have been working with in the SMC. So perfect …

Astronomy | Publications

Exploring missing values imputation techniques with an internship student

grigoris July 5, 2024 July 27, 2024

From July 1 (2024) and for the next three months I will be closely working* with a Physics undergrad, named Simos Vlassis, who followed my Python course and wanted to dive into more interesting stuff with Python. Therefore, I found the opportunity to offer him the possibility to work on …

Astronomy

The 2024 Summer School for Astrostatistics in Crete is ready to launch!

grigoris July 5, 2024 July 5, 2024

It is Friday night and only two days are left before another Summer School for Astrostatistics in Crete ! Everything is ready and I am excited for a totally new iteration of our school. I have to admit though that after three already successful events we have streamlined the process. …

Astronomy

New paper: de Wit et al. 2024: Investigating episodic mass loss in evolved massive stars: II. Physical properties of red supergiants at subsolar metallicity

grigoris May 22, 2024 June 10, 2024

Stephan extends the work he has performed previously in the Magellanic Clouds to RSGs identified in the ASSESS project in galaxies at subsolar metallicity. Investigating episodic mass loss in evolved massive stars: II. Physical properties of red supergiants at subsolar metallicity S. de Wit, A.Z. Bonanos, K. Antoniadis, E. Zapartas, …

Astronomy | Publications

New paper: Establishing a mass-loss rate relation for red supergiants in the Large Magellanic Cloud

grigoris May 17, 2024 June 10, 2024

This is a paper led by Kostas from the ASSESS team where we investigated the mass-loss in LMC/s RSGs. Interestingly this made its way to the astrobites site. Establishing a mass-loss rate relation for red supergiants in the Large Magellanic Cloud K. Antoniadis, A.Z. Bonanos, S. de Wit, E. Zapartas, …

Astronomy | Publications

The 2024 Summer School for Astrostatistics in Crete – the announcement

grigoris March 6, 2024 March 6, 2024

The deadline for the 2024 iteration of the Summer School for Astrostatistics in Crete is approaching fast. We are excited to host this event, which actually starts to settle as an annual event. And why not since it seems there is a huge need in practical training in statistics and …

Astronomy

New paper: X-Shooting ULLYSES: Massive Stars at low metallicity: II. DR1: Advanced optical data products for the Magellanic Clouds

grigoris February 28, 2024 February 28, 2024

Paper II of the XShootU collaboration is finally accepted at A&A! That is a cornerstone paper for the collaboration since it presents the analysis of the observations and provides the final scientific products with which the whole collaboration (and everybody else) can work with. X-Shooting ULLYSES: Massive Stars at low …

Astronomy | Publications

Introducing students to Python – a university course

grigoris February 6, 2024 February 28, 2024

I have been using Python almost 15 years now! Starting from 2, over 3 and the many advances in the meantime (e.g. astropy!). So, this semester (Sprint 2024) i will be teaching the course “Introduction to Python for Physicists” (F-254) at the University of Crete. This will be an intro …

Astronomy

New paper: Investigating episodic mass loss in evolved massive stars: I. Spectroscopy of dusty massive stars in ten southern galaxies

grigoris December 14, 2023 December 15, 2023

A paper that collectively presents the results from our intensive observing campaign in the ASSESS project, focusing on the southern galaxies (a forthcoming paper will deal with the northern ones). Investigating episodic mass loss in evolved massive stars: I. Spectroscopy of dusty massive stars in ten southern galaxies A.Z. Bonanos, …

Astronomy | Publications

How does the distance affects the stars we see?

grigoris September 15, 2023 September 15, 2023

With increasing distance fainter stars, and therefore those of lower luminosity, older populations, become less observable. This means that with increasing distance we actually probe different parts of a Color-Magnitude diagram (CMD), which mainly consists of the brightest and more evolved massive stars. This is best shown in this figure …

Astronomy