More than astrophotography, an astronomical exploration.
Close encounters
David Cruz · Astromidnight
In Canes Venatici, the Whirlpool Galaxy shows us its spiral arms face-on. At the tip of one of them, the small NGC 5195 passes behind and tugs on the arm with its gravity.
| Catalogue | Messier, 1773 · NGC 5194 |
| Type | Interacting spiral galaxy |
| Distance | ≈ 28 million light-years |
| Field | 80.8′ × 54.0′ |
| Scale | 0.78″ / pixel |
| Orientation | 118° · south-east up |
| RA (centre) | 13h 29m 57s |
| DEC (centre) | +47° 13′ 38″ |
| Constellation | Canes Venatici |
| Objects in field | M51 · NGC 5195 · 6 background galaxies · HD 117815 |
Distance to M51 from the tip of the red giant branch with Hubble (McQuinn et al. 2016, 8.58 Mpc); NASA gives 31 million and Chandra 26 million light-years. Distances to the background galaxies calculated from redshift (SIMBAD, NED), with H0 = 70 km/s/Mpc; that of IC 4277 is not published. Distance to HD 117815 from Gaia parallax (SIMBAD). No real width: the field mixes M51 with far more distant background galaxies. Position of M51 taken from the AstroBin label; the other labels were offset, so we used SIMBAD coordinates.
16 h 14 min of light
Each tick is one exposure. 233 in total, with the camera at −10 °C and gain 100. Calibrated with 50 darks, 50 flats and 50 bias. The Moon stayed below 65 % 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)
Player One Anti-Halo Pro Dual-Band Ha+OIII Filter 2"
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