AAPOD2 Image Archives

2025, June 2025 Charles Lillo 2025, June 2025 Charles Lillo

New Discovery of Faint Nebulosity Around a Cataclysmic Variable Star

Amid a rich starfield, faint red and teal wisps of ionized gas swirl around ASASSN-19ds, a cataclysmic variable (CV) star centered between two brighter foreground stars. This rare nebulosity, revealed through over 55 hours of deep exposure, marks an extraordinary discovery. CVs seldom show extended emission, making this a significant find. The intricate structure and color separation suggest a mix of ionized hydrogen (Hα, red) and oxygen (OIII, teal), hinting at complex interactions from past outbursts or surrounding interstellar material.

The image was part of a collaboration between Daniel Stern, Jon Talbot, and Dana Patchick, and the discovery was formally analyzed in a recent academic paper by Dr. Howard Bond (arXiv:2506.11306). Taken from Chile with a CDK-24 telescope, the data reveal subtle filaments and diffuse structures often missed in shorter exposures. This observation adds a rare specimen to the catalog of nebulae associated with CVs and contributes valuable insight into the life cycles of these energetic binary systems.

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2021, September 2021 Jason Matter 2021, September 2021 Jason Matter

NEW DISCOVERY - PaStDr 8 / The Bärenstein Nebula and the Supernova remnant G354-33

Image Description and Details : We are very proud to present Patchick-Strottner-Drechser 8 (PaStDr for short) the latest discovery of our team consisting of Dana Patchick from the US, Xavier Strottner from France and Marcel Drechsler from Germany.

6 MONTHS OF WORK, 68 NIGHTS AT THE CHILESCOPE AND 133 HOURS OF EXPOSURE TIME WERE NECESSARY TO IMAGE THIS EXTREMELY FAINT NEBULA.

Our discovery is a previously unknown potential planetary nebula in the constellation Sagittarius.
The structure has a diameter of almost one degree in the night sky and a distance of about 840 light years to Earth.

The special feature of this photo are the extremely filigree and blood red filaments of the supernova remnant G354-33, which can be seen in the left part of the image. This is the first photo ever taken of this almost unknown supernova remnant. In 2004 G354-33 was mentioned as a possible SNR in a scientific paper. However, with our work we were able to confirm G354-33 as a true SNR.

The scientific paper on this SNR, on which we worked with Professor Robert Fesen of Dartmoor College, can be found here:
https://arxiv.org/pdf/2102.12599.pdf

It is noteworthy that PaStDr 8 does not appear approximately spherical as usual, but appears much brighter and denser in the west (note, in the night sky the west is shown on the right and the east on the left).
We suspect that the structure of this candidate interacts with supernova remnant G354-33 or is distorted by its shock.
Measurement of the distance between the two structures suggests spatial proximity.

Our thanks to Sergey from Chilescope, who strongly supported us with this project.
We would also like to give special thanks to the many donors without whom this costly photograph would never have been possible. Especially the residents of my home community Bärenstein in Germany should be mentioned here, who also supported our project financially. We thank you so much!

Data on the central white dwarf:
- GAIA WD candidate WDJ194511.31-445954.57
- Pwd: 94.2645
- magnitude: 14.42
- Parallax: 3.8190
- Distance: 258 parsecs (+/- 2 parsecs)
- pm (mas/yr): RA -16,368 / -1,400
- Temperature: 8868,67 K
- Ultraviolet: FUV 12.602 / NUV 13.192

Acquisition data
H-alpha : 193 x 1200s (64.3 hours)
OIII : 153 x 1200s (52 hours)
RGB : 16.5 hours (5.5 hours per channel)
total exposure time : 132.8 hours

used telescopes
2 ASA 0.5 Newton (T2 and T3 on Chilescope, parallel operation)
mirror : 500 mm
focal length : 1900 mm
focal ratio : f/3.8

Copyright: Marcel Drechsler

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