The story of a star that survived its own supernova explosion is one of cosmic resilience. Located within the Milky Way galaxy, this remarkable star shone even brighter after being struck by a massive explosion in 2012. Its journey to becoming a supernova survivor began thousands of years ago, and it has captivated scientists ever since.

The spiral galaxy NGC 1309, situated about 100 million light-years away in the constellation Eridanus, is home to this incredible star. In stunning images captured by the NASA/ESA Hubble Space Telescope, the galaxy reveals its intricate details: bluish stars, dark brown gas clouds, and a pearly white center. The image also showcases hundreds of distant background galaxies, each one a cosmic wonder in its own right.

The remarkable story of this supernova survivor begins with two significant events: SN 2002fk in 2002 and SN 2012Z in 2012. While the first event was a perfect example of a Type Ia supernova, which occurs when the core of a dead star (a white dwarf) explodes, the second event was different – it was classified as a Type Iax supernova.

Unlike its Type Ia counterpart, SN 2012Z did not completely destroy the white dwarf, leaving behind a ‘zombie star’ that shone even brighter than before. This phenomenon has never been observed before, and scientists have used Hubble observations to study this extraordinary event in detail.

In fact, these observations also made it possible to identify the white dwarf progenitor of a supernova for the first time ever, providing valuable insights into the cosmic processes that shape our universe. The story of this star’s survival is a testament to the awe-inspiring power and complexity of the cosmos.

The discovery of an ultra-hot Jupiter exoplanet named TOI-2109b has left astronomers on high alert, as this extreme planet is now spiraling towards its star at a breakneck pace. Located a staggering 870 light-years from Earth, this gargantuan gas giant completes an orbit around its star in just 16 hours – a record that makes it the closest hot Jupiter ever discovered.

“We’re witnessing a cosmic death dance,” says Dr. Jaime A. Alvarado-Montes, a Macquarie Research Fellow who led the international study published on July 15 in The Astrophysical Journal. “TOI-2109b is super-close to its star, and its mass is nearly five times that of Jupiter. It’s like Mercury’s mass, but it takes just 16 hours for this huge gas giant to orbit its star.”

The team analyzed transit timing data from multiple ground-based telescopes, NASA’s TESS mission, and the European Space Agency’s CHEOPS satellite spanning 2010 to 2024. The results revealed subtle changes in the planet’s orbit, confirming that TOI-2109b may be spiraling towards its star.

The researchers have identified three possible fates for this doomed exoplanet: it could be torn apart by tidal forces, plunge directly into its star, or have its gaseous envelope stripped away by intense radiation, leaving only a rocky core. This cataclysmic event could provide valuable insights into the mysteries of planetary evolution and the formation of rocky worlds.

The study suggests that some rocky planets in other solar systems might be the stripped cores of former gas giants – a possibility that could reshape our understanding of planetary evolution. As astronomers continue to monitor TOI-2109b over the next three to five years, they will detect the predicted orbital changes, providing real-time observation of a planetary system in its death throes.

This remarkable discovery has left scientists on high alert, and it’s only a matter of time before we witness the impending doom of this ultra-hot Jupiter. As we gaze into the cosmos, we are reminded that there is still so much to learn about our universe and its many secrets waiting to be uncovered.

The discovery of a retrograde planet in the nu Octantis binary star system has sent shockwaves through the astronomical community. Led by Professor Man Hoi Lee from the University of Hong Kong, an international team of researchers has confirmed the existence of this unprecedented planet, which orbits in the opposite direction to its parent stars. The findings, published in Nature, have shed new light on the formation and evolution of planets in tight binary systems.

The nu Octantis system consists of two stars: a primary subgiant star, nu Oct A, with about 1.6 times the mass of the Sun, and a secondary star, nu Oct B, with approximately half the mass of the Sun. The two stars orbit each other with a period of 1,050 days. An additional periodic signal in the radial velocity observations was first reported by Dr David Ramm during his PhD studies at the University of Canterbury, New Zealand, in 2004. This signal suggested the presence of a Jovian planet of about twice the mass of Jupiter orbiting around nu Oct A, with a period of approximately 400 days.

However, the existence of this planet was controversial due to its wide orbit and the strong theoretical grounds against its formation. To settle the debate, the research team obtained new high-precision radial velocity observations using the European Southern Observatory’s (ESO) HARPS spectrograph. The analysis confirmed the presence of the planet signal, with stable fits that required the planetary orbit to be retrograde and nearly in the same plane as the binary orbit.

Another key focus of the study was the determination of the nature of the secondary star, nu Oct B. The mass of nu Oct B suggested that it could be either a low-mass main-sequence star or a white dwarf. Using the adaptive optics imaging instrument SPHERE at ESO’s Very Large Telescope, the research team observed the system and found that nu Oct B was not detected, indicating that it must be a very faint white dwarf.

The discovery that nu Oct B is a white dwarf opens new possibilities for how the retrograde planet may have originated. The research team proposed two scenarios: either the planet formed in a retrograde disc of material around nu Oct A accreted from the mass ejected by nu Oct B, or it could be captured from a prograde orbit around the binary into a retrograde orbit around nu Oct A.

As astronomers continue to search for planets in different environments, this study highlights that planets in tight binary systems with evolved stellar components could offer unique insights into the formation and evolution of planets. The research uses two facilities operated by ESO: HARPS and SPHERE.