Mission
Astroserver is a private, community supported non-profit organization with affordable solutions in research astronomy. The team offers expertise mainly in stellar astrophysics, spectroscopy, non-LTE model atmosphere calculations, assistance with publications and media content production, and help with service observations. These services are similar to the tasks of post-doctoral and graduate researchers. Therefore, our activity can be integrated into the programme of graduate schools and research institutes. To wrap-up: Astroserver is your "occasional post-doc".
The main goal of the Astroserver Team is to provide precise and reliable measurements of stellar atmospheric parameters in a consistent way across the Hertzsprung-Russell Diagram and make it accessible to everyone. The accuracy of these solutions depends on the choice of the model, the quality of input atomic data and observations. Therefore, our Team continuously improves the models and revise the atomic data input by analyzing high quality observations of standard objects. Beyond the main mission the Team is also keen on finding solutions to challenging problems on the frontiers of applied stellar spectroscopy.
Interested researchers: Please consider our services in the budget plan of your grant applications! Upon request we contribute to such proposals free of charge.
Feel free to contact us for more information!
- 2023
An 18.9-minute Blue Large-Amplitude Pulsator Crossing the "Hertzsprung Gap" of Hot Subdwarfs
Blue large-amplitude pulsators (BLAPs) represent a new and rare class of hot pulsating stars with unusually large amplitudes and short periods. Up to now, only 24 confirmed BLAPs have been identified from more than one billion monitored stars, including a group with pulsation period longer than 20 min ...
- 2024
A seven-Earth-radius helium-burning star inside a 20.5-min detached binary
Binary evolution theory predicts that the second common envelope (CE) ejection can produce low-mass (0.32 - 0.36 solar mass) subdwarf B (sdB) stars inside ultrashort-orbital-period binary systems. Their helium cores are ignited under nondegenerate conditions. With the orbital decay driven by gravitational-wave (GW) radiation, the minimum orbital periods of detached sdB binaries could be as short as 20 minutes. However, only four sdB binaries with orbital periods ...
- 2022
Orbital and atmospheric parameters of two O-type subdwarf binaries: BD-11° 162 and Feige 80
Using high-resolution spectra the orbital and atmospheric parameters of BD-11° 162 and Feige 80 have been solved. Masses of the companions and the sdOs were obtained, and the photospheric chemical abundances of the main-sequence stars for elements with available lines in the optical range have been derived.
- 2017
Atomic diffusion in the atmosphere of Feige 86
A re-analysis of the ultraviolet and optical spectra of Feige 86 found large abundances of xenon in its atmosphere. The star shows a rich, sharp-lined peculiar spectrum both in the ultraviolet and the optical, which marks active atomic diffusion processes.
