| Object: Arp 257 (UGC 4638 & companion) | Date: 2019 February 10 |
| Peculiarity: Irregular clumps. | |
| Constellation: Hydra | Time & altitude: 23.00 UT 36º |
| Catalogue data: | Seeing (5 high): 3/5 |
| R.A: 8h 52m | Transparency (5 high): 4/5 |
| Dec: -2º 22 | Telescope: 0.5m f4.1 Dob. |
| Magnitude 15.0 (but see notes) | Eyepiece 8mm Ethos x260 |
| Galaxy size (mins) 2.7 x 2.1 | Filters: None |
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Notes: It is easy to find the location of Arp 257, there is a noticeable line of three equidistant 12th magnitude stars nearby. Observed near culmination. Sources disagree about Arp 257’s magnitude. Megastar lists UGC 4638 as 14.8 and companion MCG+0-23-6 as 15.6. Kanipe/Webb state 15 & 17. That the main galaxy has a UGC designation implies it is no fainter than 14.5 (blue photographic). In these viewing conditions a 14.5 galaxy should be easy to see. However, this object is desperately faint and difficult. Only after studying the field for 20 minutes did I glimpse a faint oval glow. I only saw this on and off using AV. There was no sign of the MCG companion. |
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