During the XXXth General Assembly of the International Astronomical Union (in Vienna, Austria) I participated in a number of different meetings. In particular:
1. A poster at the IAU Focus Meeting FM14 on IAU’s role on global astronomy outreach, the latest challenges and bridging different communities (August 23, 2018):
“A paradigm to develop new contributors to Astronomy”
G. Maravelias, E. Vourliotis, K. Marouda, I. Belias, E. Kardasis, P. Papadeas, J. D. Strikis, E. Vakalopoulos, O. Voutyras
One of the most regular activities of amateur clubs is scientific outreach, a paramount chan-
nel to disseminate scientific results. It is typically performed through talks given by both ex-
perts (professional astronomers) and non-experts to a diverse audience, including amateur as-
tronomers. However, this is a rather passive, one-way, approach. The advance of technology
has provided all the tools that can help the audience/amateurs to become more active in the
scientific output. What is often missing is the proper guidance. To address that within the
Greek amateur community the Hellenic Amateur Astronomy Association materialized a train-
ing program (free-of-charge and open-accessed) to develop scientific thought and the practical
capabilities for amateurs to produce valuable results. The program ran from November 2014 to
May 2015 focusing each session (month) to: the Sun, variable stars, comets, planets, artificial
satellites, meteors. A professional and/or an experienced amateur astronomer was leading each
session consisting of a theoretical part (highlights of the field, necessary observational tech-
niques) and a hands-on part (observations and data analysis). At least 50 unique participants
gained significant experience by following parts or the complete program.
arXiv: 1810.04562
2. A talk at the meeting of Division G: Stars and Stellar Physics (August 24 and 27, 2018)
“Rings around B[e] Supergiants”
G. Maravelias, M. Kraus, L. Cidale, M. Borges Fernandes, M. L. Arias, A. F. Torres
Massive stars affect strongly the insterstellar medium through their intense stellar winds and their rich chemically processed material as they evolve. In specific short-lived transition phases (e.g. B[e] Supergiants, Luminous Blue Variables, Yellow Hypergiants) the mass-loss becomes more enhanced and usually eruptive. This leads to the formation of a complex circumstellar environment, which is not always well understood. To improve our knowledge on these phases we examined the structures found around the B[e] supergiants for a sample of Galactic and Magellanic Cloud sources. Using high-resolution optical and near-infrared spectra, we examine a set of key emission features ([OI], [CaII], CO bandheads) to trace their physical conditions and kinematics in their formation regions. Assuming Keplerian rotation of the circumstellar material we find that each B[e] Supergiant is surrounded by a unique distribution of single and/or multiple equatorial rings. Moroever, we find that these structures seem to be more stable and long-lived around single stars rather than binaries that show significant spectroscopic and photometric variability.
3. A poster at the IAU Symposium 346 on High-mass X-ray binaries: illuminating the passage from massive binaries to merging compact objects (August 27 – 31, 2018)
Clarifying the population of HMXBs in the Small Magellanic Cloud
G. Maravelias, A. Zezas, V. Antoniou, D. Hatzidimitriou, F. Haberl
Almost all confirmed optical counterparts of HMXBs in the SMC are OB stars with equatorial decretion disks (OBe). These sources emit strongly in Balmer lines and standout when imaged through narrow-band Hα imaging. The lack of secure counterparts for a significant fraction of the HMXBs motivated us to search for more. Using the catalogs for OB/OBe stars (Maravelias et al. 2017) and for HMXBs (Haberl & Sturm 2016) we detect 70 optical counterparts (out of 104 covered by our survey). We provide the first identification of the optical counterpart to the source XTEJ0050-731. We verify that 17 previously uncertain optical counterparts are indeed the proper matches. Regarding 52 confirmed HMXBs (known optical counterparts with Hα emission), we detect 39 as OBe and another 13 as OB stars. This allows a direct estimation of the fraction of active OBe stars in HMXBs that show Hα emission at a given epoch to be at least ∼ 75% of their total HMXB population.
arXiv: 1811.10933
And a short note:
I had opted to present the poster works as e-posters, i.e. displayed as an electronic pdf/presentation on interactive monitors which would be placed at each poster halls. The motivation behind this was the fact that the posters could be uploaded before the official start of each session and be available over the whole (two-week) period. But there were some issues:
1. There were only two monitors at each hall, so if somebody else was talking over their poster you had to wait… and wait… and wait… It happened to me that I wanted to show my poster to a colleague but some other people were in front of the monitor for such a long time that it became obvious that it would be easier finally to show it through my laptop.
2. It was not finally that appealing to use as somebody would have to go and see the list of all posters and select each poster to see in detail. In other words you couldn’t browser the posters like what you do when you walk around in the poster session. It would have been much nicer to have the posters rolling somehow randomly in the monitors and continuously to widen their visibility.
3. Interactive it might have been but it was not easy to navigate (e.g. change the session and see another than the active one at that time), while in many cases there were a few bugs (zooming in that resulted in hiding some presentations, or crashing during the slide change).
