Skip to main content


BL Lacertae

"Twinkle, twinkle quasi-star
Biggest puzzle from afar
How unlike the other ones
Brighter than a billion suns
Twinkle, twinkle, quasi-star
How I wonder what you are."
- George Gamow, "Quasar" 1964.

Gamma Cassiopeiae and the Be Stars

Gamma Cassiopeiae and the Be Stars

UV Ceti and the flare stars

Proxima Centauri
Figure 1: An infrared image of Proxima Centauri, the closest star to Earth (other than the Sun) and a flare star. From the 2MASS Atlas Image Gallery. Atlas Image courtesy of 2MASS/UMass/IPAC

Eta Carinae

Sovereign of the South

NASA/HST image of Eta Carinae and its pair of billowing gas and dust clouds.

P Cygni

P Cygni from the<br />
Second Digital Sky Survey

RR Tauri

"Stars are equal; it is not birth but mass that makes the difference"

(paraphrasing Voltaire on men)

Birth of a star: getting to the main sequence

FU Orionis

All in the FUor Family

T Tauri

An Interesting Neighborhood to Live In


TU Cassiopeiae

"Cepheids are the most useful stars in the sky."

-L. Campbell and L. Jacchia, 1941, in The Story of Variable Stars

The Most Useful Variable Stars

W Virginis

Not Your Classical Cepheid

Virgo  Cluster
Click image to enlarge.


AAVSO 49 Bay State Rd. Cambridge, MA 02138 617-354-0484