How much aperture does it take?
Seeing Albireo through a telescope
A gold star and a blue star, side by side, 35 arcseconds apart. The most obvious colour contrast in the sky and completely unaffected by light pollution — the best target there is for a city beginner's first night.
Through three telescopes, under a suburban sky
Each circle is the true field of a 10 mm eyepiece. Same target, same sky; only the aperture changes.
Detailed
Detailed
Detailed
The aperture it takes, by sky
Albireo does not care about light pollution: it is bright, and the air, not the sky glow, sets the limit.
| Level | Milky Way blazing | Milky Way, barely | No Milky Way |
|---|---|---|---|
| Detectable | 10 mm | 10 mm | 10 mm |
| Recognisable | 50 mm | 50 mm | 50 mm |
| Detailed | 60 mm | 60 mm | 60 mm |
When to look
Summer and autumn evenings in the northern hemisphere.