astronomy Archives

Where the Dyson sphere on and off fits of M77 differ most, and how new photometry changes the comparison. In each panel, the upper sub-panel shows the median posterior AGENT-on (solid red) and AGENT-off (dashed blue) model spectra with shaded 16–84% posterior bands and the fitted photometry overplotted (open black circles), while the lower sub-panel shows the percent deviation of the AGENT-on model relative to the AGENT-off model, with the shaded band giving the 1σ uncertainty propagated in quadrature from the two independent fits. -- [astro-ph.GA]

The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies. V. When Galaxies Glow with Industry

by Keith CowingAugust 14, 2026August 14, 2026

[astro-ph.GA] We present the most robust stellar population synthesis (SPS)-based search for galaxy-spanning technological waste heat to date, applied to 129 nearby galaxies spanning a wide range of spectral energy […]

The Helix Nebula and the cosmic recycling of stellar material. The bright central nebula surrounds a white dwarf, the remnant of the star that created it. Farther out, newly revealed bow shocks show fragments of material cast off by that star colliding with surrounding interstellar gas. The fragments become progressively smaller and more disrupted as they are stripped, shredded and mixed into space. The new MOTHRA data is shown in black, with previous data from the Hubble Space Telescope and the Kitt Peak 4m telescope in color. Credit for the previous data: NASA, ESA, C. R. O’Dell (Vanderbilt University) and M. Meixner, P. McCullough and G. Bacon (Space Telescope Science Institute).

Astrochemistry

Astrochemistry: A Cosmic Recycling System In Action In The Helix Nebula

by Keith CowingAugust 14, 2026August 14, 2026

[Northwestern University] An international team of scientists, including Northwestern University astrophysicists, has captured an unprecedented view of a dying star’s remains in the act of being recycled.

Mid-infrared image of the IRS 3 environment, observed with NACO (VLT) and MIRI/MRS (JWST). The background image is in the L band (3.6 μm), the yellow inset shows a slice from the channel 3 long data cube covering 15.41−17.98 μm. The light blue boxes highlight an area of 1.6″ × 1.6″. A yellow × marks the SMBH Sgr A*, located at RA 17h45m40.05s and Dec −29:00:28.120. The projected distance between Sgr A* and IRS 3 is about 4.4 arcsec, corresponding to 0.17 parsec. The NACO field of view (FOV) is about 13.5″ × 6.5″. In both the NACO and MIRI MRS images, the emission from IRS 3 is dominated by the extended envelope of the AGB star. -- University of Cologne

Astrochemistry

A Stellar Envelope Near The Black Hole Sgr A* Contains Water

by Keith CowingAugust 12, 2026August 12, 2026

[University of Cologne] Studies of the star IRS 3, located near the black hole at the centre of our galaxy, suggest that the star is emitting large quantities of gas […]

Penalty incurred when phase is unknown, with polarimetry. The true phase set is α = (150◦, 120◦, 90◦, 60◦, 30◦, 5◦). Left: known-phase radius consequence, in which trial phases are fixed to the true set. Middle: unknown-phase radius consequence, in which trial phase tuples are marginalized over the sampled grid while the normalized I400 lightcurve shape is included with the intensive observables. Right: unknown-phase to known-phase penalty ratio. -- [astro-ph.EP]

Astronomy & Telescopes

Multi-epoch Ultraviolet Observables For Breaking The Radius-albedo Degeneracy In Directly Imaged Exoplanets

by Keith CowingAugust 12, 2026August 12, 2026

[astro-ph.EP] Direct imaging measures how bright a planet appears in reflected starlight, but brightness alone cannot tell whether the planet is large and dark or small and bright. This radius-albedo […]

CAD layout of the MANTIS spacecraft showing how the instrument unit and spacecraft unit are distinct, with a single 37-pin micro-D connector between the two. This is a significant reduction in complexity to prior CU-LASP CubeSats where the instrument and spacecraft by necessity are integrated. -- [astro-ph.IM]

Cubesats and smallsats

Optomechanical Design of the MANTIS SmallSat: An Extreme-, Far- and Near-Ultraviolet Spectrograph for Exoplanet Host Stars

by Keith CowingAugust 12, 2026August 12, 2026

[astro-ph.IM] The MANTIS (Monitoring Activity of Nearby sTars with uv Imaging and Spectroscopy) observatory is a compact, multi-instrument small satellite designed for simultaneous extreme- (EUV; 100 – 560 Angstrom), far- […]