Galaxies NGC 672, IC 1727
History
The galaxy NGC 672 was discovered on October 26, 1786 by Wilhelm Herschel with his 18.7 "reflector telescope. Herschel seemed to have overlooked the neighboring galaxy IC 1727 due to its lower luminosity. It was only discovered on November 29, 1896 by Isaac Roberts with a 20" reflector telescope discovered photographically. [277]
Physical Properties
The two galaxies are physically very close and show gravitational interaction with one another. IC 1727 shows a strong asymmetry in the apparent distribution of young stars, while that of older stars is more even. The galaxy NGC 672 shows no asymmetry in the distribution of stars of different ages. The distance from NGC 672 is estimated at 7.22 ± 0.10 Mpc and that from IC 1727 at 7.14 ± 0.10 Mpc. It is estimated that star formation in the two galaxies occurred in two intervals 20-30 and 450-700 million years ago. [426]
The galaxy NGC 684 was discovered by Wilhelm Herschel on the same night as NGC 672. [277]
| Name | RA | Dec | Type | Bmag | Vmag | Dim | Dreyer Description | Identification |
|---|---|---|---|---|---|---|---|---|
| NGC 672 | 01 47 54.0 | +27 25 58 | Gx (SBc) | 11.5 | 10.9 | 6.00 × 2.4 | F, pL, mE 80° | UGC 1256, MCG 4-5-11, CGCG 482-16, IRAS 01450+2710, VV 338, KCPG 40B |
| NGC 684 | 01 50 14.1 | +27 38 46 | Gx (Sb) | 13.3 | 12.4 | 3.20 × 0.6 | F, vlE, * 13 f 100" | IC 165, UGC 1292, MCG 4-5-17, CGCG 482-22, IRAS 01474+2724 |
| IC 1727 | 01 47 30.0 | +27 19 57 | Gx (SBm) | 12.1 | 11.5 | 5.70 × 2.4 | F, L, st inv, I 157 nf | UGC 1249, MCG 4-5-9, CGCG 482-14, VV 338, KCPG 40A |
| IC 1731 | 01 50 12.5 | +27 11 46 | Gx (SBc) | 14.0 | 13.3 | 1.50 × 1.0 | F, E npsf, bM, prob spir | UGC 1291, MCG 4-5-18, CGCG 482-21 |
Finder Chart
The galaxy pair NGC 672 + IC 1727 is located in the constellation Triangulum, about 40 arc minutes northwest of the small open star cluster Collinder 21. The best observation time is July to February.
