Does brightest mean biggest or closest?

Neither. Apparent magnitude is how bright a star looks from Earth, which combines its true luminosity with its distance. Canopus is far more luminous than Sirius and appears dimmer only because it is about nine times further away.

Why do the names look like “Alp CMa”?

That is the Bayer designation — Alpha Canis Majoris. The catalogue leaves the proper-name column blank for most entries, so this saver maps the well-known designations to their common names and falls back to the catalogue number otherwise.

Yes. It comes from The Bright Star Catalogue (Hoffleit & Jaschek) served by VizieR at the Centre de Données astronomiques de Strasbourg. Nothing is invented or simulated, and if the source cannot be reached the saver reports that instead of drawing something plausible.

Does it cost anything or need an account?

No. Every screensaver here is free, runs in the browser and needs no sign-up. This one uses a public API that requires no key.

The Brightest Stars Screensaver

The Brightest Stars screensaver ranks the brightest stars in the sky by apparent magnitude, read live from the Bright Star Catalogue via VizieR at Strasbourg. Magnitude runs backwards — lower is brighter — and the scale is logarithmic, so Sirius at -1.46 is about twenty-five times brighter to the eye than a star at 0.85. It runs in the browser with nothing to install; press ESC to exit.

How the The Brightest Stars screensaver works

The saver reads The Bright Star Catalogue (Hoffleit & Jaschek) served by VizieR at the Centre de Données astronomiques de Strasbourg.

No account and no key: the request goes straight from your browser, or from this site's own refreshed copy of the feed where the source does not allow browser access.

Values are drawn on a canvas that resizes with the window, so it works on a laptop or a wall display.

If the source is unreachable the saver says so on screen rather than showing stale numbers as though they were current.

A worked example

Each star gets a disc sized by its actual brightness ratio and tinted by spectral class — blue-white for hot O and B stars, yellow for G, orange-red for K and M — with its proper name, Bayer designation, spectral type and magnitude. Sirius leads, then Canopus, Arcturus, Alpha Centauri and Vega.

Settings & tips

Accent and Background recolour the display without changing the data.
Add it to a Multi-view grid to watch it alongside other live savers.
Press ESC at any time to leave fullscreen.

Frequently asked questions

Does brightest mean biggest or closest?: Neither. Apparent magnitude is how bright a star looks from Earth, which combines its true luminosity with its distance. Canopus is far more luminous than Sirius and appears dimmer only because it is about nine times further away.
Why do the names look like “Alp CMa”?: That is the Bayer designation — Alpha Canis Majoris. The catalogue leaves the proper-name column blank for most entries, so this saver maps the well-known designations to their common names and falls back to the catalogue number otherwise.
Is this real data?: Yes. It comes from The Bright Star Catalogue (Hoffleit & Jaschek) served by VizieR at the Centre de Données astronomiques de Strasbourg. Nothing is invented or simulated, and if the source cannot be reached the saver reports that instead of drawing something plausible.
Does it cost anything or need an account?: No. Every screensaver here is free, runs in the browser and needs no sign-up. This one uses a public API that requires no key.

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