Seeing the Andromeda Galaxy through a telescope

A large, soft, oval glow — brighter towards the middle and fading with no edge you can point at. Bigger than the full Moon, and almost nobody sees it that way because only the core is bright enough.

16 mmDetectable
79 mmRecognisable
238 mmDetailed

Millimetres of aperture to reach each level. Observing heuristics, quoted at Bortle 4 and adjusted per class of sky — somebody else's eyes, somebody else's night.

Through three telescopes, under a suburban sky

Each circle is the true field of a 25 mm eyepiece. Same target, same sky; only the aperture changes.

70 mm · 20×

Detectable

130 mm · 36×

Recognisable

250 mm · 70×

Detailed

The aperture it takes, by sky

Millimetres of aperture to reach each level. Observing heuristics, quoted at Bortle 4 and adjusted per class of sky — somebody else's eyes, somebody else's night.

Level	Milky Way blazing	Milky Way, barely	No Milky Way
Detectable	8 mm	16 mm	25 mm
Recognisable	42 mm	79 mm	126 mm
Detailed	125 mm	238 mm	377 mm

What it takes to see it

The cheapest model in the catalogue that reaches each level under the suburban sky of the views above (Bortle 6), at its observed price. The thresholds are observing heuristics, not optics; a darker sky needs less, and the table above says how much.

130 mm · 26×

Recognisable · from 79 mm

Sky-Watcher Heritage 130P FlexTube

€197 seen 7 Oct 2026 at Astroshop

The most-recommended first telescope of the last decade. The open tube needs a light shield in a garden with a street lamp.

See it at Astroshoppaid link

Also search at First Light Optics · Optique Unterlinden · Pierro Astro · Teleskop-Express

254 mm · 50×

Detailed · from 238 mm

Omegon Advanced X N 254/1250

€622 seen 7 Oct 2026 at Astroshop

24.4 kg in all, of which the tube is 15 kg. One eyepiece in the box: the 25 mm gives 50× on 254 mm, an exit pupil of 5.1 mm, and any higher power needs a second eyepiece bought separately. The fan behind the mirror runs on 12 V, and the listing's contents name no power source for it. At f/5 it needs collimating before it shows what it can.

See it at Astroshoppaid link

Also search at First Light Optics · Optique Unterlinden · Pierro Astro · Teleskop-Express

What more aperture buys

The main dust lane shows in 100–150 mm from a dark site, as the edge where the glow stops short along one side. The two companion galaxies, M32 and M110, show in 80 mm.

When to look

Autumn evenings in the northern hemisphere.

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