Every picture on this page is an artistic rendering that we created ourselves, and none of them is a photograph of a real object. They are here to show what kinds of things the app helps you find and what makes each of them a different challenge.
An emission nebula is a cloud of gas that shines because a nearby group of hot young stars is exciting it, and hydrogen does most of the work, which is why these clouds look deep red. The dark shapes that cut across the glow are dense lanes of dust that block the light from behind.
This is the kind of target that rewards a modified camera or a hydrogen alpha filter, and it copes better than most objects with a bright moon.
A reflection nebula produces no light of its own. Fine dust near a few bright stars scatters their light, and blue light scatters best, so the cloud takes on a soft blue colour that no filter can improve. It is a target for dark skies and patient exposure, since the dust is faint.
Because the colour comes from starlight, an unfiltered camera does well here.
Spiral galaxies are enormous, but their light is spread so thinly that they are among the most demanding subjects in the sky. The warm centre is made of old stars and the bluer arms are where new stars are being born, with dark dust lanes running along the inner edges.
Expect to gather several hours of exposure under a dark sky before the arms begin to appear.
A globular cluster is a tight sphere of many thousands of very old stars that orbit the centre of a galaxy together. Toward the middle the stars are so crowded that they merge into a single glow, and towards the edge they separate into individual points.
These are forgiving targets that show well even from a town, which makes them a good choice on a night with a bright moon.
A planetary nebula has nothing to do with planets. It is a shell of gas that a star like our sun casts off near the end of its life, glowing in teal from oxygen and in red from hydrogen and nitrogen while the faint remnant of the star sits at the centre.
They are small and bright, so a longer focal length helps, and narrowband filters bring out the colours very well.
Not every rewarding night needs a telescope. A camera on a tripod, a wide lens and a dark horizon are enough to record the Milky Way arching over the trees, and on a night without a moon the whole arch of it can be seen with the naked eye.
This is the picture that most beginners should try first, and the journal article about a first night with a camera and a tripod explains how.
A comet usually shows two tails that point in different directions. The curved golden one is made of dust and follows the path of the comet, while the straight blue one is made of ionised gas that the solar wind pushes directly away from the sun.
Bright comets are rare and change quickly, which is why AstroNight includes them in its calendar.
The renderings were produced with our own software from noise, simulated dust and star fields, so they resemble the sky without copying any existing photograph. Real astronomical photographs are the work of their photographers and are protected by copyright, which is why none are used here.
