Prepare an observation

The objects below are those that rise above 30° while the sky is in full darkness, longest window first. Neither condition is enough on its own: a target high in broad daylight cannot be observed, and neither can a dark sky over a target that has set.

If you already know what you are after, name it: a Messier number, M31 for instance, or a right ascension and a declination in degrees.

Whether a target fits in the frame depends on the optical train, not on the telescope alone. The table below gives how finely each one samples the sky; the chart under it draws what each one frames, on the real sky and around the target you chose. Both come from the focal length and the sensor, held in the inventory.

The table above answers « which instrument covers what », and that question has no target. This chart answers the other one: on this object, what does it give. It shows the real sky, photographed, with the field of the chosen configuration drawn on it, to scale and at the angle you set.

It appears once you have named a target above. Its images come from the Centre de données astronomiques de Strasbourg, so nothing loads before you agree, as with the videos and the maps elsewhere on this site.

These two panels come from meteoblue, not from us. They bring what we cannot yet measure: the seeing, in arc seconds. Nothing loads before you agree, as with the videos and the maps elsewhere on this site.

And right now, what is the weather doing?