For the first time, astronomers have captured video footage of bubbles sloshing about on the surface of a distant star, R Doradus.

Their results, now published in Nature, were made with observations from the European Southern Observatory’s Very Large Telescope (VLT), situated atop a mountain in Chile.

These bubbles, known as convection cells, are commonly observed on the sun as well. As such, the fact the cells exist in itself isn’t a mystery, but it’s rare feat to have spotted them on a distant star. Similar cells have been earlier spotted in Betelgeuse, a red-giant just like R Doradus, using VLT. But the new study is the first to track similar cells moving.

The cells, captured in observation studies done between July and August 2023, are the biggest known to astronomers yet. The researchers say some 75 suns can fit into an individual convection cell appearing on the star. (For context, R Doradus is some 350 times larger than our sun).

The convection cells move a lot faster than theory predicts, completing one revolution a month.

The convection cells

But the cells are formed just the same way as they do so in sun and stars like it. Hot gas from inside the star rises up to the surface, taking advantage of its density that’s lower than the cooler gas in the upper layers. But the journey upward isn’t without hurdles, as the energetic atoms lose that energy in clashes with atoms from the upper layers. This cools down the gas, inevitably slowing it down. But many of those atoms escape the star’s surface.  Most of them don’t, and sinks back into the star. The gas now radiates dimmer light in comparison to the bulk of the surrounding hot gas on the surface that’s yet to lose their energy. The contrast can be picked up with sensitive telescopes here on earth – outlining a grain on the star’s surface.

But the latest finding has also left the researchers curious. The convection cells move a lot faster than theory predicts, completing one revolution a month. While theorists are yet to explain that, the authors speculated our sun’s future. A billion years had presumably gone by since R Doradus was a star just as hot and small like the sun. And perhaps we’re witness to our sun’s fate already, as it’ll turn into a similar red-giant star some five billion years from now.

In a remarkable discovery, astronomers have unearthed what could be the oldest known reference to a total solar eclipse, embedded within the ancient Hindu text, the Rig Veda. This revelation places the eclipse approximately 6,000 years ago, predating previous records by millennia.

The Rig Veda, a sacred compilation of hymns and philosophical discourses from around 1500 B.C., has long been recognized for its rich historical and astronomical references. Traditionally, these references have been used to track celestial events like the position of the vernal equinox. By studying these texts, astronomers can pinpoint historical astronomical phenomena due to Earth’s axial precession—a gradual wobble that shifts the positions of celestial events over millennia.

In particular, the Rig Veda describes the vernal equinox’s location shifting from Orion around 4500 B.C. to the Pleiades around 2230 B.C., indicating that some of the text’s celestial records predate its compilation. Recent research by Mayank Vahia from the Tata Institute of Fundamental Research in Mumbai and Mitsuru Soma from the National Astronomical Observatory of Japan has now identified references that likely describe a total solar eclipse.

Their analysis, published in the Journal of Astronomical History and Heritage, highlights passages that describe the sun being “pierced” by darkness and gloom, with “magic arts” of the sun vanishing—imagery fitting for an eclipse. Importantly, these descriptions precede the well-known Hindu mythological story of Rahu and Ketu, suggesting they were documented before this mythos emerged.

Further examination of the Rig Veda’s astronomical references narrowed down the eclipse to a period when the vernal equinox was in Orion, occurring just days before an autumnal equinox. The analysis identified two potential dates for the eclipse: October 22, 4202 B.C., and October 19, 3811 B.C. These dates surpass previous records, including a clay tablet from Syria dated to around 1375 B.C. or 1223 B.C. and a rock carving in Ireland from approximately 3340 B.C.

“We propose that the eclipse recorded in the Rig Veda refers to observations made of an eclipse around 4000 BC. By analyzing the description, we propose that the eclipse was the one that occurred in 4202 BC or else in 3811 BC. We propose that it was observed in Central Asia. To our knowledge, this is one of the oldest known references to a specific total solar eclipse mentioned in the historical literature,” the authors said in their study.

This discovery not only pushes back the timeline of recorded astronomical events but also offers a fascinating glimpse into ancient astronomical knowledge and its transmission through sacred texts.

In a pioneering advancement in electronics, scientists at the S. N. Bose National Centre for Basic Sciences, Kolkata, India, have unveiled a revolutionary transistor that operates using single molecules controlled by mechanical forces. This innovative approach could lead to significant improvements in quantum information processing, ultra-compact electronics, and advanced sensing applications.

The research team, led by Dr. Atindra Nath Pal and Biswajit Pabi, has developed a transistor using a technique known as the mechanically controllable break junction (MCBJ). Instead of relying on traditional electrical signals, this novel transistor uses mechanical forces to control the flow of electricity. The process involves breaking a macroscopic metal wire with a piezoelectric stack to create an extremely precise sub-nanometer gap, into which a single molecule, ferrocene, is inserted.

Ferrocene, composed of an iron atom sandwiched between two cyclopentadienyl (Cp) rings, exhibits unique electrical properties when subjected to mechanical manipulation. The researchers discovered that the orientation of the ferrocene molecules between silver electrodes significantly impacts the transistor’s performance. Depending on how the molecules are aligned, the device can either enhance or reduce electrical conductivity, highlighting the crucial role of molecular geometry in designing these advanced transistors.

Further experiments involving gold electrodes and ferrocene at room temperature revealed a notable reduction in resistance. The measured resistance was approximately 12.9 kΩ, which is about five times lower than the quantum resistance but much less than the typical resistance of a molecular junction, which usually hovers around 1 MΩ. This reduction suggests the potential for creating low-power molecular devices with impressive efficiency.

These findings represent a major leap forward in the development of more sustainable and high-performance electronic devices. By harnessing mechanical forces to control electron transport at the molecular level, this new technology opens up possibilities for greener electronics, lower power consumption, and enhanced functionality in quantum computing and sensing technologies. The implications of this research could reshape the future of electronic device design and application.