The wide-field treasures include double star Zibal and the Silver Coin Galaxy
1. The Cosmic Question Mark
Equipment: 10×50
Nu (ν) Ceti is the dot at the bottom of the 2¼° long question mark that, when it is in the south of the sky, extends straight up above it. Four 6th magnitude yellowish stars make the curved part of the question mark, and the 7th magnitude star in the middle of the upright is a hot brilliant white colour that contrasts nicely with the rest of the Cosmic Question Mark asterism.
2. M77
Equipment: 15×70
M77 lies slightly less than 1° east of Delta (δ) Ceti. It’s a Seyfert galaxy, which means that most of its light comes from gas spiralling into its central black hole. This makes it quite easy to see the nucleus, but any skyglow will obscure the galactic disc, making the galaxy look star-like in binoculars. If you intend to try a Messier marathon next spring, practise finding the M77 galaxy, which is an early twilight object.
3. Zibal
Equipment: 10×50
Let’s continue with a nice easy double star. Zibal (Zeta (ζ) Eridani) is a pure white star that shines at mag. +4.8. To the northwest, 5 arcminutes away, is its mag. +6.6 companion. This is a chance line of sight pairing, not a true binary; the golden companion appears 1.8 magnitudes fainter than Zibal, but it is more than four times as distant and this conceals another reality: it is intrinsically 1.6 magnitudes more luminous.
4. 37 Ceti
Equipment: 15×70
The double star 37 Ceti lies 2.5° west of Theta (θ) Ceti. Its components are 49 arcseconds apart, which should be an easy split even with lower magnifications, but the magnitude of the companion is only mag. +7.9, which is 13 times less bright. This magnitude difference can make it tricky to split, which is why we are using larger binoculars that should be mounted for steadiness.
5. T Ceti
Equipment: 10×50
Identify 7 Ceti and navigate 2° to the southeast, where by far the reddest star in the region is the semi-regular variable (mag. +5.0 to +6.9) T Ceti. It is a red giant that has technetium in its spectrum. The most stable isotope, Tc98, has a half-life of 4.2 million years. This is much shorter than the billions of years age of the star and provides incontrovertible evidence for stellar nucleosynthesis.
6. The Silver Coin Galaxy and NGC 288
Equipment: 10×50
Nearly 5° south of Diphda (Beta (β) Ceti), you will find a right-angle of 5th magnitude stars, below which is a rhombus of fainter stars. NGC 253, the Silver Coin Galaxy, is an elongated glow nearly 1° southwest of the rhombus. Now look about 2° in the direction of Alpha (α) Sculptoris, where you should see the glow of globular cluster NGC 288.