My first astro image for 2025...
NGC1566 - colloquially known as the Spanish Dancer Galaxy - lies at a distance of around 69 million light years in the southern sky constellation of Dorado.
NGC1566 hosts an “active galactic nucleus” (AGN) – emitting significant energy across the EM spectrum that is theorised to result from accretion of matter by a supermassive black hole at the galaxy core. Some AGN host galaxies – including NGC1566 –have been observed to show dramatic flux and spectral changes (by orders of magnitude) in optical (Alloin et al, 1986) and X-ray (Oknyansky et al 2019) regimes over a range of remarkably short timescales (ie days (!!) to years). Galaxies displaying such features are referred to as possessing “changing-look AGNs”. (Ricci and Trakhtenbrot, 2023)
My image has an exposure time of ~27 hours, captured across 4 Nov 2024 - 7 Jan 2025. The end result is a reasonably deep image, with numerous quasars detected, including one down to Mag 21.39 and another with a redshift of z=2.400 (approx. 11 billion years ago)
Skywatcher 200PDS, Skywatcher NEQ6, QHY294C, Optolong UV-IR filter (225 x 5mins), Optolong L-Extreme filter (49 x 10mins)
Astrobin version:
https://www.astrobin.com/uncfga/0/
Refs:
Alloin, D., Pelat, D., Phillips, M., Fosbury, R., Freeman, K. (1986) Recurrent outbursts in the broad-line region of NGC 1566,
The Astrophysics Journal, 308, 23-25
Oknyansky, V. L., Winkler, H., Tsygankov, S. S., Lipunov, V. M., Gorbovskoy, E. S., Van Wyk, F., Buckley, D. & Tyurina, N. V. (2019). New changing look case in NGC 1566.
Monthly Notices of the Royal Astronomical Society, 483(1), 558-564.
Ricci, C., & Trakhtenbrot, B. (2023). Changing-look active galactic nuclei.
Nature Astronomy, 7(11), 1282-1294.
