Messier 103 (also known as M103, or NGC 581) is a small open cluster of many faint stars in Cassiopeia.
It is located 9,400 light-years from the Sun and is about 15 light years across. It holds two prominent stars, of which the brightest is magnitude 10.5, and in the center of the cluster, another magnitude 10.8 red giant. Another bright foreground object is the double star Struve 131, but is not a member of the cluster. Cluster membership is about 172 stars based on >50% probability of gravitational attachment that binds the cluster together. M103 is between 12.6 to 25 million years in age.
| Object | M103 Open Star Cluster |
| Constellation: | Cassiopeia |
| Position: | RA 01h 33.2m DEC +60° 42' |
| Apparent Size: | 6 arcmin |
| Apparent Magnitude: | 7.4 |
| Distance in light years: | 9400 ly |
| Photo Data | |
| Date of Expose: | 26.10.2019 |
| Location: |
Knottenried/Oberallgäu/Germany (1002m ASL) GPS: 47°36’13“ N / 10°11’24“ E |
| Telescope: | TS 14" RC f/d 8.0 / 2845mm |
| Camera: | Sony A7Ra mod @ T sensor = +14.1°C |
| Field of View: | 0.72 x 0.48 deg |
| Pixel Scale/Resolution: | 0.35 arcsec/px |
| Expose frames/times: | OSC RAW 12x90s, 18 darks, ISO 3200 |
| Total expose: | 18min 0s |
| Filter: | no |
| Mount: | HPS 10Micron GM 3000 |
| Software: | DSS 3.3.4, Photoshop CC |
| Remarks: |
© Photos by Peter Cerveny
© Object description/intro text fully or partially by Wikipedia,
which is released under the Creative Commons Attribution-ShareAlike 4.0 International License