The Astronomical Journal (often abbreviated AJ in scientific papers and references) is a peer-reviewed monthly scientific journal owned by the American Astronomical Society and currently published by Institute of Physics Publishing. It is one of the premier journals for astronomy in the world. Until 2008, the journal was published by the University of Chicago Press on behalf of the American Astronomical Society. The reason for the change were given by the society as the desire of the University of Chicago Press to revise its financial arrangement and their plans to change from the particular software that had been developed in-house. The other two publications of the society, the Astrophysical Journal and its supplement series, followed in January 2009. The journal was established in 1849 by Benjamin A. Gould. It ceased publication in 1861 due to the American Civil War, but resumed in 1885. Between 1909 and 1941 the journal was edited in Albany, New York. In 1941, editor Benjamin Boss arranged to transfer responsibility for the journal to the American Astronomical Society. The first electronic edition of The Astronomical Journal was published in January, 1998. With the July, 2006
For several years, astronomers and cosmologists have theorized about the existence of an additional planet with a mass 10 times greater than that of Earth, situated in the outermost regions of the solar system. This hypothetical ...
Astronomers using NASA's Hubble Space Telescope have found evidence that the spinning of a small comet slowed and then reversed its direction of rotation, offering a dramatic example of how volatile activity can affect the ...
Planetary Sciences
Mar 26, 2026
0
125
For decades, astronomers have struggled to differentiate giant planets from brown dwarfs, a class of objects more massive than planets but too small to ignite nuclear fusion like true stars. Through a telescope, these cosmic ...
Astronomy
Mar 18, 2026
0
42
The discovery of a possible "super-Earth" less than 20 light-years from our own planet is offering scientists new hope in the hunt for other worlds that could harbor life, according to an international team including researchers ...
Astrobiology
Oct 23, 2025
1
177
As NASA's New Horizons spacecraft traveled through the Kuiper Belt at a distance of more than 5.5 billion miles from Earth, an international team of astronomers used the far-flung probe to conduct an unprecedented experiment: ...
Observations with the James Webb Space Telescope (JWST) have provided new clues about how the exoplanet WASP-121b has formed and where it might have originated in the disk of gas and dust around its star. These insights stem ...
Planetary Sciences
Jun 3, 2025
0
202
An unusual planetary system with three known ultra-low density "super-puff" planets has at least one more planet, according to new research led by researchers from Penn State and Osaka University.
Planetary Sciences
Dec 3, 2024
1
114
Astronomers from the University of Wisconsin–Madison and Harvard–Smithsonian Center for Astrophysics (CfA) have inspected a Galactic open cluster known as NGC 2506 as part of the WIYN Open Cluster Study. Results of the study, ...
The Event Horizon Telescope (EHT) Collaboration has conducted test observations achieving the highest resolution ever obtained from the surface of the Earth, by detecting light from the centers of distant galaxies at a frequency ...
Astronomy
Aug 27, 2024
0
519
A team of astronomers and citizen scientists has discovered a planet in the habitable zone of an unusual star system, including two stars and potentially another exoplanet.
Astronomy
Apr 30, 2024
0
811
