Filament
A strand of cool gas suspended over the photosphere by magnetic fields, which appears dark as seen against the disk ...
A strand of cool gas suspended over the photosphere by magnetic fields, which appears dark as seen against the disk ...
A small, wide-field telescope attached to a larger telescope. The finder is used to help point the larger telescope to ...
A small telescope used to aim your main scope at an object in the sky. Finderscopes have low magnifications, wide ...
An extremely bright meteor. Also known as bolides, fireballs can be several times brighter than the full Moon. Some can ...
A faint red star that appears to change in brightness due to explosions on its surface.
The phenomenon of emitting light upon absorbing radiation of an invisible wavelength.
The distance (usually expressed in millimeters) from a mirror or lens to the image that it forms. In most telescopes ...
A lens or mirror's focal length divided by its aperture. For instance, a telescope with an 80-mm-wide lens and a ...