| Object: M103 (NGC 581) | Date: 2018 December 12 |
| Type: Open cluster | |
| Constellation: Cassiopeia | Time & altitude: 19.20 UT 79º |
| Catalogue data: | Seeing (5 high): 3/5 |
| R.A: 1h 33m | Transparency (5 high): 4/5 |
| Dec: 60º 42 | Telescope: 0.5m f4.1 Dob. |
| Magnitude 7.0 | Eyepiece 17mm Ethos x120 |
| Size (mins) 6 | Filters: None |
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Notes: Why is this not known as the Christmas Tree cluster? Its outline is a well-proportioned isosceles triangle with the brightest star at the apex. The cluster stands out well from the background Milky Way because there is a void of stars around it to the N, W and S. A pleasing object. |
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