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Leo Triplet

27 December 2024-1 January 2025

Jubera
- TS Optics Photoline 115
- Moravian C3-61000
(More info later in technical sheet)

The Leo Triplet, also known as the M66 Group, is a small group of galaxies located about 35 million light-years away in the constellation of Leo. This group is composed of three spiral galaxies: M65, M66, and NGC 3628.

The photograph of the Leo Trio gave us a good first contact with the fascinating world of small bodies in the solar system. We also took this photograph in Jubera, in the magnificent conditions that occurred during the turn of the year, 2024-2025. Compared to Andromeda, these galaxies are small for the refractor we carried, however, the sky conditions allowed us to take this reasonable shot of the set. To our surprise, we discovered a tricolor trace while exploring the noise level of the background of the stacked frame from the shots of the night of the 28th to the 29th (once stacked, combined the RGB channels and stretched).

This trace could not be an artifact, clearly, since it came from a total of more than 140 shots taken over approximately two and a half hours. Assuming that it was some nearby celestial object, I calculated the coordinates, the angle with respect to the frame and the length of the trace. From this, and the total integration time, I calculated the trajectory and the position that it should have in the following days. The calculation went well, and indeed, the stack of the next day showed the tricolor trace again, in the estimated position (with a little error, but reasonable). On returning from the trip to Jubera, I went to NASA's Small Body Database to identify the object, which turned out to be asteroid 49316 (1998 VX23) belonging to the Asteroid Belt, 7 km in diameter. With this unexpected result, I decided to explore the rest of the frame, seeing a total of 8 tricolor traces, which I identified in the same way as the first one. Discussing the matter with Pablo de la Fuente, a scientific colleague of ours at the UAM, it turns out that he is an expert in the Tycho software. Pablo put the frame into this software, and Tycho identified many more objects in the frame (of which only some are shown in the frame below, which was made by Pablo de la Fuente).

Zoom As for the galaxies, here is a high-resolution detail frame.

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TECHNICAL INFORMATION

Location        Jubera (Soria), Coord.=41.20170, -2.36595, Alt.=933 
                SQM=21.84 mag/arsec2 Bortle=Class 3
Main Tube       TS Optics Photoline 115 mm f/7 EDT Triplet Apo. 
                Flat 0.79x, F.L. eff. 632 f/5.5
Guider Tube     Homemade ThorLabs 2" tube assembly 
                F.L. eff. 200 f/4
Main camera     Moravian C3-61000, 9576 x 6388, 3.76 µm
Guider Camera   ZWO ASI290MM Mini, 1936 x 1096, 2.9 µm
Mount           iOptron GEM45

Processing info

The frames that make up the images shown in this blog correspond only to the stacking of the RGB shots from the night of the 28th to the 29th. This is a simple and direct stacking, where no subsequent noise reduction has been performed, because the Moravian was working at 25 below zero and with Dither, so that when dealing with a considerable number of frames, using a noise reduction process was not worth it.

You can find a lot of information about Leo Triplet in teh following video from NASA.

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