last week has been consistently clear weather, occasional high veil clouds. This evening clear skies and was able to observe a few comets : 29P, C/2022 QE78 and C/2025 D1. With the 2nd setup was able to obtain spectra in H-alpha area in high resolution of Be stars : Phi Leo and kappa Draconis (spectra are free available for use and can be downloaded from the BeSS-database.)
spectroscopic and comet observations on 29 march
comet and spectroscopic observations on 27 march 2025
it was a nice sunny day, towards evening high veil clouds appeared and disappeared late in the evening. However, it remained a low transparent sky. A few comets could be observed, with my 0.4-m f/3.8 newtonion telescope, including: 29P, C/2022 QE78, C/2023 H5 and C/2023 Q1, all images with photometric Bessel-R filter. With the 11″ Cassegrain telescope and LHiReSS III spectrograph I was able to capture spectra of PZ Gem ( 7 x 1200 sec exposure) in high resolution in H-alpha region. All my spectra could be seen and free downloaded in the BeSS-database after they are approved.
spectroscopic observation on 20 march
During this evening i could obtained a spectra in H-alpha region and high resolution of PZ Gem. (8 x 1200 sec exposure)
spectroscopic observations on 18 march 2025
During the evening with clear sky, i could obtain 2 spectra of Be-stars in High-resolution in H-alpha region. Be-stars that could be obtained are: QY Gem and gam Cas.
comet and spectroscopic observations on 17 march
after a sunny day, we also got a clear night with low temperatures around freezing. Transparency was initially reasonable with SQM in zenith of 18.7 to go to 19.2 later in the evening/night and drop back as the moon came out. Comets that could be observed with my 0.4-m f/3.8 Newtonion telescope were: 29P, 496P, P/2019 Y3, C/2022 E2, C/2023 H5, C/2023 Q1, C/2025 D1 (not detected in background of magn. 20.3). With the 2nd observatory ( 0.28-m f/10 cassegrain telescope with LHiReSS-III spectrograph), high resolution spectra of H-alpha region were obtained from PZ Gem (exposure: 8 x 1200 sec) and 4 Her (exposure: 3 x 1200 sec)
manuscript “The birth of Be star disks… ” published
The paper made by Jonathan Labadie-Bartz was today published: “The birth of Be star disks I. from localized ejection to circularization”; abstract:
Classical Be stars are well known to eject mass to build up a disk, but the details governing the initial distribution and subsequent evolution of this matter into a disk are in general poorly constrained through observations.
Aims. By combining high-cadence time-series spectroscopy with contemporaneous space photometry from the Transiting Exoplanet Survey Satellite (TESS), we have sampled about 30 mass ejection events in 13 Be stars. Our goal is to constrain the geometrical and kinematic properties of the ejecta as early as possible
spectroscopic observations on 11 march
during an short period of clear sky, i could obtain spectra of 2 Be-stars: gam Cas (10 x 60 sec exposure and PZ Gem (8 x 1200 sec exposure )
comet observations on 9 march
Later in the evening there was e period of clear sky. I could observe comet 29P (30 x 120 sec exposures) with Bessel-R filter