More than astrophotography, an astronomical exploration.
Hickson 68
David Cruz · Astromidnight
In Canes Venatici, five galaxies crowd together in a small compact group, about 100 million light-years away. Beside them shine the large spiral NGC 5371 and two stars of our own galaxy, one orange and one blue, thousands of times closer.
| Catalogue | Hickson Compact Groups, 1982 · HCG 68 |
| Type | Compact group of galaxies |
| Distance | ≈ 100 million light-years |
| Field | 75.5′ × 50.4′ |
| Scale | 0.52″ / pixel |
| Orientation | 178° · south up |
| RA (centre) | 13h 54m 29s |
| DEC (centre) | +40° 22′ 44″ |
| Constellation | Canes Venatici |
| Objects in field | HCG 68 (5 NGC) · NGC 5371 · quasar at z = 4.7 |
Distance of HCG 68 taken from NGC 5353, the brightest member (about 30 Mpc, Hubble 2024); the NED Tully-Fisher and Faber-Jackson distances range from 26 to 31 Mpc. No real width: the field combines Milky Way stars, the group and much more distant background objects. Distance of LEDA 2161383 calculated from redshift (SIMBAD), with H0 = 70 km/s/Mpc; light travel time of the quasar calculated with the Planck cosmology (H0 = 67.7, Ωm = 0.31). Size of NGC 5371 calculated from the SIMBAD major axis (3.9′) and the distance of the group. The AstroBin labels sat beside the galaxies, so all positions come from SIMBAD coordinates.
20 h 00 min of light
Each tick is a 240-second exposure. 300 in total, with the camera at −10 °C and gain 100. Calibrated with 50 darks, 50 flats and 50 bias. The Moon stayed below 5 % 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