Stars | Astronomy.com

A black-and-white photograph shows two men standing side by side in dark, flowing academic or ceremonial robes and matching, structured black caps. The man on the left, who has a mustache, holds a small notebook while writing in it with a pen, and both men look down at the pages together. They stand against a light-colored wall that creates high contrast with their dark attire.

Today in the History of Astronomy

Oct. 8, 1873: The birth of Ejnar Hertzsprung

Hubble image of variable star RS Puppis

How to become a variable star observer

A Hubble Space Telescope image of Sirius A, the brightest star in the night sky, appearing as an intensely bright white-blue point of light with four prominent diffraction spikes extending diagonally across the dark blue background. Sirius B, its much fainter white dwarf companion, is visible as a small distinct point of light in the lower left of the frame.

Observing, Science, Stars

Which naked-eye star is richest in metals?

A complex, octagonal satellite wrapped in black panels and gold foil dominates the upper portion of the frame inside a large, dark circular testing chamber. Near the bottom left, a person wearing a white lab coat and blue surgical cap kneels while touching one of the satellite’s rectangular panels. A intense white light shines from the center of the structure, creating sharp highlights and high contrast against the dark background.

Today in the History of Astronomy

Aug. 8, 1989: The Hipparcos satellite launches

A circular image shows a bright teal, comet-like streak streaming horizontally across a pitch-black field filled with countless tiny stars. The teal streak features a brighter, compact head near the center of the circle, trailing off into a wispy blue-green tail toward the left. The surrounding dark background is dotted with mostly white and warm orange pinpricks of light, creating high contrast with the central glowing shape.

Today in the History of Astronomy

Aug 3, 1596: David Fabricius discovers Mira

Andromeda’s star formation is slowing down

A richly detailed telescope image of a star-forming nebula, filled with swirling clouds of blue, orange, and pink gas and dust. Dark pillars of dense dust cut through the center of the image, surrounded by glowing nebular material and hundreds of orange and yellow stars scattered throughout. A bright cluster of young stars illuminates the lower right portion of the image, casting a warm glow against the surrounding gas clouds.

RCW 36: A bird of prey sails away

Is this the first known binary system to produce two supernova remnants?

An artist's illustration of two stars against a dense, starry background with red and blue nebula clouds. A large, intensely bright white star dominates the left side of the image, while a smaller, vivid blue star glows to its right, suggesting a binary star system.

How can a young blue giant have a white dwarf companion star that’s billions of years older?

A vintage, monochromatic photograph shows a grainy, dark grey surface with a single, small white star shining brightly in the exact center of the frame. The star emits a subtle, four-pointed cross of light against the textured, speckled background. The outer edges of the image are framed by uneven, darker tattered borders that appear worn and decayed.

Today in the History of Astronomy

July 16, 1850: Bond and Whipple photograph Vega

A dark night sky chart transitions from a deep purple at the top to a warm orange glow along a jagged black mountain horizon at the bottom. A crescent moon and several small, white star dots are scattered across the sky, each accompanied by a white text label. In the lower-center of the frame, a single bright white dot sits next to the bold labels "SATURN" and "JUPITER" just above the date text "December 21."

Today in the History of Astronomy

June 17, 2 BCE: A conjunction between Venus and Jupiter

An artistic color illustration depicts a large, glowing orange-red star on the left with dark spots on its surface, stretching slightly toward a smaller, brilliant white star on the right. The white star is enveloped in a bright, glowing red ring and has a faint, hourglass-shaped white mist radiating from its center. A thin stream of glowing red matter connects the two stars across a black background dotted with tiny white specks.

Today in the History of Astronomy

June 12, 2021: Seiji Ueda discovers Nova Herculis 2021