The year,
in four.
A body is highest, steadiest and least smeared by air the moment it crosses the meridian, so what a night is worth is decided months in advance by which objects transit while it is dark. Pick a quarter before you pick a date.
Winter
The longest dark and the worst steadiness of the year, both at once. The jet stream sits over these latitudes in January, so the 610 spends the quarter at low power and the 355 does most of the work.
| Object | Class | In | Mag | Transit | From the eyepiece |
|---|---|---|---|---|---|
| M42 | Orion Nebula | Orion | 4.0 | 22:10 | The Trapezium splits to six on a 2/5 night |
| M45 | Pleiades | Taurus | 1.6 | 20:40 | Naked eye from the lawn; the 127 holds all seven |
| NGC 869/884 | Double Cluster | Perseus | 4.3 | 19:50 | Needs the field, not the aperture |
| M35 | Open cluster | Gemini | 5.3 | 23:30 | And NGC 2158 behind it, four times further off |
Spring
Galaxy season, and the dark hours shorten to nothing by the solstice — after 10 June there is no astronomical dark at this latitude at all, and the programme moves to doubles, the moon and the sun.
| Object | Class | In | Mag | Transit | From the eyepiece |
|---|---|---|---|---|---|
| M51 | Whirlpool galaxy | Canes Venatici | 8.4 | 23:05 | Both cores, and the bridge on a 21.7 sky |
| M81 / M82 | Galaxy pair | Ursa Major | 6.9 | 21:50 | One field at 157×, and they look nothing alike |
| M13 | Globular cluster | Hercules | 5.8 | 02:40 | Resolves to grain at 210× on the 610 |
| Cor Caroli | Double star | Canes Venatici | 2.9 | 22:30 | 19″ apart — the easy one to learn on |
Summer
Short dark, warm air, and the best seeing of the year. The Milky Way runs overhead through Cygnus and the sweeping eyepiece stays in the 355 for most of the quarter.
| Object | Class | In | Mag | Transit | From the eyepiece |
|---|---|---|---|---|---|
| M57 | Planetary nebula | Lyra | 8.8 | 23:50 | The ring holds its hole even at low power |
| Albireo | Double star | Cygnus | 3.1 | 00:40 | Gold and blue. Nobody expects to like it most |
| M27 | Planetary nebula | Vulpecula | 7.4 | 01:10 | Apple-core shape with an O-III filter in |
| M11 | Open cluster | Scutum | 5.8 | 23:20 | Low, and worth the low — a wedge of a thousand |
Autumn
The quarter the deep-sky sessions are booked for. Dark returns before most people have eaten, the air is dry after the equinox, and Andromeda is at the meridian before midnight.
| Object | Class | In | Mag | Transit | From the eyepiece |
|---|---|---|---|---|---|
| M31 | Spiral galaxy | Andromeda | 3.4 | 21:40 | Two dust lanes on a moonless night |
| M33 | Spiral galaxy | Triangulum | 5.7 | 22:10 | The sky-quality test object. If you see it, it is a good night |
| NGC 7662 | Planetary nebula | Andromeda | 8.3 | 21:05 | Blue, small, and obviously not a star at 287× |
| M15 | Globular cluster | Pegasus | 6.2 | 19:40 | Tighter core than M13, and it shows |
Deep-sky sessions run in new-moon week only, and this is the quarter they fill. If you want the 610 on M33 rather than on Saturn, book October or November and book early.
Always
up.
North of declination 37.6° a star never touches the horizon at this latitude — it circles the pole and stays. These nine are the brightest of them, straight out of the same catalogue the field behind this page is drawn from, so what is written here and what is turning behind it are the same numbers.
Vega
Mag 0.03
RA 18h 37m · Dec +38.8°
Capella
Mag 0.08
RA 5h 17m · Dec +46.0°
Deneb
Mag 1.25
RA 20h 41m · Dec +45.3°
Alioth
Mag 1.77
RA 12h 54m · Dec +56.0°
Dubhe
Mag 1.79
RA 11h 04m · Dec +61.8°
Mirfak
Mag 1.79
RA 3h 24m · Dec +49.9°
Alkaid
Mag 1.86
RA 13h 48m · Dec +49.3°
Menkalinan
Mag 1.90
RA 5h 60m · Dec +44.9°
Polaris
Mag 2.02
RA 2h 32m · Dec +89.3°