Astronomy Archives

September 18, 2024September 18, 2024 by Evan Gough

The Early Universe Had a Lot of Black Holes

The Hubble Ultra Deep Field seen in ultraviolet, visible, and infrared light. Image Credit: NASA, ESA, H. Teplitz and M. Rafelski (IPAC/Caltech), A. Koekemoer (STScI), R. Windhorst (Arizona State University), and Z. Levay (STScI)

The Hubble Deep Field and its successor, the Hubble Ultra-Deep Field, showed us how vast our Universe is and how it teems with galaxies of all shapes and sizes. They focused on tiny patches of the sky that appeared to be empty and revealed the presence of countless galaxies. Now, astronomers are using the Hubble Ultra-Deep Field and follow-up images to reveal the presence of a large number of supermassive black holes in the early Universe.

This is a shocking result because, according to theory, these massive objects shouldn’t have been so plentiful billions of years ago.

September 17, 2024September 17, 2024 by Matt Williams

Astronomers Have Found a Star with a Hot Jupiter and a Cold Super Jupiter in Orbit

Artist's vision of a cold super-Jupiter in the HD 118203 system. It is an extremely massive gas planet orbiting its star in an orbit six times that of Earth. Credit: NCU/ Maciejewski, G. et al (2024)

Located in the constellation Ursa Major, roughly 300 light-years from Earth, is the Sun-like star HD 118203 (Liesma). In 2006, astronomers detected an exoplanet (HD 118203 b) similar in size and twice as massive as Jupiter that orbits very closely to Liesma (7% of the distance between Earth and the Sun), making it a “Hot Jupiter.” In a recent study, an international team of astronomers announced the detection of a second exoplanet in this system: a Super Jupiter with a wide orbit around its star. In short, they discovered a “Cold Super-Jupiter” in the outskirts of this system.

September 17, 2024September 20, 2024 by Matt Williams

Future Gravitational Wave Observatories Could See the Earliest Black Hole Mergers in the Universe

A simulation of two merging black holes. Credit: Simulating eXtreme Spacetimes (SXS) Project

In February 2016, scientists at the Laser Interferometer Gravitational-wave Observatory (LIGO) confirmed they made the first-ever detection of gravitational waves (GWs). These events occur when massive objects like neutron stars and black holes merge, sending ripples through spacetime that can be detected millions (and even billions) of light-years away. Since the first event, more than 100 GW events have been confirmed by LIGO, the Advanced VIRGO collaboration, and the Kamioka Gravitational Wave Detector (KAGRA).

Moreover, scientists have found numerous applications for GW astronomy, from probing the interiors of supernovae and neutron stars to measuring the expansion rate of the Universe and learning what it looked like one minute after the Big Bang. In a recent study, an international team of astronomers proposed another application for binary black hole (BBH) mergers: using the earliest mergers in the Universe to probe the first generation of stars (Population III) in the Universe. By modeling how the events evolved, they determined what kind of GW signals the proposed Einstein Telescope (ET) could observe in the coming years.

September 16, 2024September 17, 2024 by David Dickinson

Earth’s Shadow Nicks the Moon During This Week’s Partial Lunar Eclipse

The Moon just brushes the umbral shadow of the Earth during Tuesday night’s partial lunar eclipse.

A shallow partial lunar eclipse is on tap for the night of September 17th/18th. The eclipse is a slight one to be sure, but will be noticeable as the northwestern limb of the Moon just slips past the dark inner umbral shadow of the Earth. The eclipse is just over 8% partial at its maximum, meaning the Full Moon will look a little ‘smushed’ on one side at mid-eclipse.

September 13, 2024September 13, 2024 by Matt Williams

More Bodies Discovered in the Outer Solar System

The Subaru Telescope at the Mauna Kea Observatories, Hawaii. Credit: NAOJ

The outer Solar System has been a treasure trove of discoveries in recent decades. Using ground-based telescopes, astronomers have identified eight large bodies since 2002 – Quouar, Sedna, Orcus, Haumea, Salacia, Eris, Makemake, and Gonggang. These discoveries led to the “Great Planet Debate” and the designation “dwarf planet,” an issue that remains contentious today. On December 21st, 2018, the New Horizons mission made history when it became the first spacecraft to rendezvous with a Kuiper Belt Object (KBO) named Arrokoth – the Powhatan/Algonquin word for “sky.”

Since 2006, the Subaru Telescope at the Mauna Kea Observatory in Hawaii has been observing the outer Solar System to search for other KBOs the New Horizons mission could study someday. In that time, these observations have led to the discovery of 263 KBOs within the traditionally accepted boundaries of the Kuiper Belt. However, in a recent study, an international team of astronomers identified 11 new KBOs beyond the edge of what was thought to be the outer boundary of the Kuiper Belt. This discovery has profound implications for our understanding of the structure and evolution of the Solar System.

September 12, 2024September 12, 2024 by David Dickinson

Book Review: Is Earth Exceptional?

A new book looks at the latest scientific insights versus a key question in astronomy and space science.

It’s tough to answer a scientific question, with a just data point of one. How special are we, and how common (or rare) is the story of how life arose on the Earth in the grander drama of the cosmos?

A new book out this week entitled Is Earth Exceptional? The Quest for Cosmic Life by Mario Livio and Jack Szostak looks at the scientific state of answering this key question. The book offers a sweeping view of the nascent science of astrobiology, a multi-disciplinary field melding biology, chemistry, astronomy and more.

September 10, 2024September 12, 2024 by David Dickinson

Amateur Astronomer Finds Additional Asteroids With Remote Telescopes

Orbit — The orbit of Near Earth Asteroid 2024 QS. Credit: NASA/JPL

Three amazing recent asteroid finds show what’s possible in terms of astronomy online.

Practical astronomy is increasingly becoming an online affair. In 2023 we wrote about this trend, and highlighted how Russian observer and amateur astronomer Filipp Romanov used time on remote observatory networks to successfully discover two asteroids, which he named 623826 Alekseyvarkin and 623827 Nikandrilyich after his great-grandfathers. Now, Filipp has repeated this feat and pushed the limit of what’s possible online with the discovery of a trio of asteroids, including a rare near-Earth asteroid discovery found using a remote system.

September 9, 2024September 9, 2024 by Evan Gough

The True Size of Galaxies is Much Larger Than We Thought

Visualisation of the gas shroud of starburst galaxy IRAS 08339+6517. Astronomers struggle to observe this gas clearly, but new research found a way. Image Credit: Cristy Roberts ANU/ASTRO 3D

Ask most people what a galaxy is made up of, and they’ll say it’s made of stars. Our own galaxy, the Milky Way, hosts between about 100 to 300 billion stars, and we can see thousands of them with our unaided eyes. But most of a galaxy’s mass is actually gas, and the extent of the gas has been difficult to measure.

Researchers have found a way to see how far that gas extends into the cosmos.

September 3, 2024September 3, 2024 by Evan Gough

This Ancient Galaxy Merger Will Produce a very Luminous Quasar

This illustration depicts two quasars in the process of merging. There are many unanswered questions around galaxy mergers and the quasars that can result. Image Credit: NOIRLab/NSF/AURA/M. Garlick)

In the contemporary Universe, massive galaxies are plentiful. But the Universe wasn’t always like this. Astronomers think that galaxies grew large through mergers, so what we see in space is the result of billions of years of galaxies merging. When galaxies merge, the merger can feed large quantities of gas into their centers, sometimes creating a quasar.

Much of this is theoretical and shrouded in mystery, but astronomers might have found evidence of a galaxy merger creating a quasar.

September 3, 2024September 3, 2024 by David Dickinson

Catch a Fall Feast of Lunar Occultations in September

September offers a number of fascinating lunar occultation events worldwide.

Chances are, there’s one near you this month. The Moon is certainly busy in September, as its passage covers up (occults) multiple celestial objects worldwide. If skies are clear, you may just get a chance to see one of these events listed below, as the Moon blocks out a star, planet or star cluster.