astrophysics

Explore stellar spectral classification: OBAFGKM types, luminosity classes, HR diagram, color indices, reddening, metallicity, and modern methods to classify stars. The post Stellar Spectral Types: OBAFGKM, Lines, and HR Diagram first appeared on .

Payne's 1925 calculation was right, but the familiar story misses why it looked wrong and how Russell's independent 1929 analysis both confirmed and explicitly credited her earlier result.

China has narrowed the search for Tianwen-3’s Mars landing site to eight candidates as preparations accelerate for a 2028 sample-return mission targeting signs of ancient life.

[astro-ph.EP]. Beta Pictoris is a young and nearby planetary system hosting an edge-on debris disk and at least three gas-giant planets. Their circumplanetary environments could host exomoons and rings, a […] The post The Hill Sphere Transits of Beta Pictoris c and The Search for Another 1981-like Event appeared first on Astrobiology .

[astro-ph.EP] The flux of meteoroids reaching the Earth is continuous, ranging from microscopic grains to occasional metre and decametre scale bodies. The smallest ones fully ablate in the upper atmosphere, […] The post Sample Return Tech: Pre-impact Meteorite Strewn Field Predictions For Imminent Impactors And Meteorite Recovery appeared first on Astrobiology .

NASA’s Chandra X-Ray Observatory is the agency’s flagship mission for X-ray astronomy. On Sept. 5, 2001, NASA announced that astronomers using Chandra in October of the previous year had witnessed a fast, strong X-ray flare coming from the supermassive black hole at the center of our galaxy. This black hole, named Sagittarius A* (Sgr A*) Continue reading "Sept. 5, 2001: The Milky Way has a black …

Looking for a sky event this week? Check out our full Sky This Week column.  September 4: Get in a workout Titan, Saturn’s brightest moon, orbits its parent world with a period of about 16 days. You’ll find this moon passing near Saturn today and tomorrow, when it will be northeast and northwest of the ringed world, Continue reading "The Sky Today on Saturday, September 5: Titan near Saturn" The …

Researchers want to explore the idea that microscopic particles shed by alien civilizations have accumulated on the lunar surface, making it an archive of extraterrestrial technology.

"Some of my earliest memories are sitting with my dad in the family room watching Star Trek during the original broadcasts on NBC. I was only 4 or 5, so I don't have much memory of it, but I grew up just knowing all the stories. Star Trek was literally my mythology as a child. For me, Star Trek is about exploration—going into places we've never been. The fact that it placed such a central focus o…

We have seen that the orbits of the planets around the sun can be found, to a good approximation, by only considering a two-body system (a planet and the sun) interacting through a central force. However, all the other planets cause slight variations in the predicted path of an individual planet. Astronomers have been able to calculate the expected precession of Mercury’s apsides (due to the forc…

Nature Astronomy, Published online: 04 September 2026; doi:10.1038/s41550-026-02934-2 Little red dots (LRDs) are a new class of object uncovered by deep JWST surveys at high redshift. This Perspective summarizes our current observational understanding of LRDs and considers possible scenarios for their central engines.

The newest DESI Legacy Imaging Surveys map covers three-quarters of the sky and catalogs nearly four billion objects. This publicly-available database contains stars, galaxies, supernovae, gravitational lenses, and much more.

The Sloan Digital Sky Survey (SDSS) has officially launched its twentieth data release (DR20), featuring updated data from multiple observations projects.

Astronomers have used the MeerKAT radio telescope to detect hydrogen gas located billions of light-years away, from a period when the cosmos was billions of years younger.

UC Santa Barbara & UT Austin physicists traced runaway black hole RBH-1, traveling at 1,000 km/s, to a violent galactic collision—a first for predicted black hole mergers.

Two UMBC undergrads spent their summer at the the University of Hawai'i's Institute for Astronomy studying supermassive black holes and colliding galaxies using fresh data from the James Webb Space Telescope and Subaru Observatory. They also hiked on volcanoes, explored Hawaiian cultural history, and grew their scientific networks. The experience sharpened their research skills, opened new career…

The Nancy Grace Roman Space Telescope’s mirror may get the headlines, but its detector chips, photon-counting cameras, and downlink amplifier tell the electronics story.