Messier 7 or M7, also designated NGC 6475 and sometimes known as Ptolemy's Cluster, is an open cluster of stars in the constellation of Scorpius 980 light years from earth. The cluster is easily detectable with the naked eye, close to the "stinger" of Scorpius. With a declination of −34.8°, it is the southernmost Messier object.
Telescopic observations of the cluster reveal about 80 stars within a field of view of 1.3° across. The age of the cluster is around 200 million years while the brightest member star is of magnitude 5.6.
| Object | M7 Open Cluster |
| Constellation: | Scorpius |
| Position: | RA 17h 53m 47s / Dec -34° 50' 00'' |
| Apparent Size: | 80 arcmins |
| Apparent Magnitude: | +3.3 |
| Distance in light years: | 980 ly |
| Photo Data | |
| Date: | 28 Apr 2022 - 04 Aug 2022 |
| Location: |
El Sauce Observatory Chile (1525m ASL) GPS: 30.472529° S, 70.762999° W |
| Telescope: | CHI-1-CCD: Planewave CDK24 61cm / f6.5/3962mm |
| Camera: | FLI ProLine PL9000, 12μm, 3056x3056, @ T sensor = -10.0° |
| Field of View: | 32' x 32' |
| Pixel Scale/Resolution: | 0.62 arcsec/px |
| Expose frames/times: | L 19x300s, R 19x300s, G 23x300s, B 22x300s |
| Total expose: | 6h 55min |
| Filter: | Astrodon Luminance, Red, Green, Blue |
| Mount: | Mathis MI-1000/1250 with absolute encoders |
| Software: | Siril 1.4, Photoshop CC |
| Remarks: |
© Photos and photo data 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