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 recorded from PZ Gem (esxposure: 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
comet observations on 7 march
Xe have clear night, so i could observe some comets. comets that could be observed are: 29P, 49P, 487P, C/2022 QE78, C/2023 H5, C/2023 X2, P/2019 Y3
comet observations on 6 march
again a clear night to observe some comets. Comets that could be observed are: 29P, 49P, 276P, 487P, 496P, A/2025 A7, P/2019 Y3
comet and spectroscopic observations on 5 march
the clear sky is perfect to observe some comets: comets that could be observed are: 29P, 43P, 49P, 476P, C/2022 E2, C/2023 H5, C/2024 A1, P/2023 S1. With my second setup, i could obtain spectra in H-alpha region of Be-stars : gam Cas, PZ Gem and Phecda
manuscript published
publication of the manuscript: “The Slow-Rotating Nucleus of Comet C/2013 R1 (Lovejoy)” via Astronomische Nachrichten where my observations were used for analysis
comet and spectroscopic observations on 4 march 2025
After another beautiful sunny day it was also a clear night, transparency was slightly better than yesterday March 3. I could observe some comets such as: 29P, C/2022 QE78, C/2022 U3, C/2023 Q1, C/2024 A1, C/2024 M1 and C/2024 N4.
comet and spectroscopic observations on 3 march 2025
After a beautiful sunny day, it was also a clear night, though with a bit less transparency. I was able to observe several comets until high clouds are drift in. Still a number of comets were observed such as: 29P, 43P, 276P, 472P, 487P, 496P, A/2025 A7, C/2017 K2, P/2019 Y3. Simultaneously, with the 2nd observatory, spectra were obtained in high resolution (R~15000) in H-alpha region of the Be stars: gam Cas, PZ Gem and 53 Boo.