More than astrophotography, an astronomical exploration.
The Great Hercules Cluster
David Cruz · Astromidnight
In Hercules, more than a hundred thousand stars crowd into a ball of light 25,000 light-years away. Around it, far more distant galaxies peer out between the stars of the Milky Way.
| Catalogue | Messier, 1764 · NGC 6205 |
| Type | Globular cluster |
| Distance | ≈ 25,000 light-years |
| Field | 73.2′ × 49.0′ |
| Scale | 0.52″ / pixel |
| Orientation | 357° · north up |
| RA (centre) | 16h 41m 41s |
| DEC (centre) | +36° 28′ 01″ |
| Constellation | Hercules |
| Objects in field | M13 · NGC 6207 · IC 4617 · 1 quasar |
Distance to M13 according to NASA. Distance to NGC 6207 from the mean of Hendry et al. (2006), 20.3 ± 3.4 megaparsecs. Distance to IC 4617 and light-travel time of the quasar calculated by us from redshift (SIMBAD), with H0 = 70 km/s/Mpc. Distances to the stars from Gaia parallax (SIMBAD). No real width: the field mixes the cluster with much more distant galaxies. Image without AstroBin labels: all positions come from SIMBAD.
5 h 20 min of light
Each tick is a 240-second exposure. 80 in total, with the camera at −10 °C and gain 100. Calibrated with 50 darks, 50 flats and 50 bias. The Moon stayed below 30 % illumination throughout.
Carbon Newton 10' f/4
ZWO ASI2600MC Pro
Sky-Watcher CQ350 Pro
Askar M54 OAG · ZWO ASI120MM Mini
TS-Optics NEWTON Coma Corrector 1.0x (TSGPU)
Adobe Photoshop · Pleiades Astrophoto PixInsight · Stefan Berg Nighttime Imaging 'N' Astronomy (N.I.N.A. / NINA)
São Pedro da Gafanhoeira, Évora · 358 m
Bortle 3