# Separation

Also called: sep.

The angle between two objects — for a double star, the distance between its stars in arcseconds.

Separation decides how easy a double star is: Albireo's 34″ splits at 20×; Epsilon Lyrae's pairs, about 2.3″ apart, need 100–150× and steady air. Your telescope's [resolution](https://astropilot.space/glossary/resolution) sets the limit.

**Examples:** [albireo](https://astropilot.space/object/albireo.md), [epsilon-lyrae](https://astropilot.space/object/epsilon-lyrae.md), [mizar](https://astropilot.space/object/mizar.md)

**Related:** [Double star](https://astropilot.space/glossary/double-star.md), [Position angle](https://astropilot.space/glossary/position-angle.md), [Resolution](https://astropilot.space/glossary/resolution.md), [Angular size](https://astropilot.space/glossary/angular-size.md)

From the AstroPilot astronomy glossary: https://astropilot.space/glossary/separation