HCG 45
HCG45
5’ x 5’ | 0.3”/px | 1000 × 1000 px
Ursa Major
RA 10h 19m 10.0s DEC +59° 06’ 21.5”
HCG45 is a quartet located in the constellation Ursa Major. The four galaxies have similar distances to Earth, in the range of approximately 1 billion light-years. Three out of four members are spiral galaxies, while the faintest is lenticular. The brightest galaxy (a) is also known as PGC 30153. It has an angular size of 1.3’ ×0.5’ and is twice as large as the next biggest. Apparent magnitudes range from 15.7 units 17.4.
Details of all six galaxies are listed in the table below.
Hickson classification: SI - Group diameter: 3.4’
| Ltr | Primary Designation | Also Known As | Type | RA (J2000) | Dec (J2000) | Distance (Mly) | Angular Size | App. Mag. (B) |
|---|---|---|---|---|---|---|---|---|
| a | PGC 30153 | UGC 5564 · MCG+10-15-061 | Spiral (SAB) | 10h 19m 14s | +59° 07′ 52″ | ~1,075 | 1.27′ × 0.47′ | 15.7 |
| b | PGC 30137 | — | Spiral (Sa) | 10h 19m 05s | +59° 06′ 20″ | ~1,071 | 0.50′ × 0.30′ | 16.3 |
| c | PGC 30143 | — | Spiral (Sc) | 10h 19m 08s | +59° 05′ 04″ | ~1,123 | 0.25′ × 0.10′ | 16.7 |
| d | PGC 30156 | — | Lenticular (SO) | 10h 19m 16s | +59° 08′ 15″ | ~1,164 | 0.19′ × 0.13′ | 17.4 |
Source: SIMBAD astronomical database, Centre de Données astronomiques de Strasbourg (CDS), Distances based on Redshift (z) using H₀ = 69.6 km/s/Mpc. Apparent magnitudes in B band.
Imaging
Visibility graph at location: Remote hosting facility Roboscopes in Fregenal de la Sierra, Spain (38°N 6°W)
| Telescope | Planewave CDK14 (2563mm @ f/7.2) |
| Mount | 10Micron GM2000HPS |
| Camera | Moravian C3-61000 Pro |
| Filters | Chroma 2" Luminance |
| Software | Voyager, MW4, PixInsight |
| Capture date(s) | 27 May 2026 |
| Settings | -10°C, gain 0, bin 1 |
| Exposure | 21 × 300s @ Gain 0 (1h 45min) |
| Filters | Chroma 2" Luminance |
| Processing | WBPP, GraXpert, BXT, MAS, NXT, invert, crop |