Space & Physics
New Dust Models Shed Light on the End Stages of Sun-like Stars
New Insights into Hydrogen-Deficient Stars: Study of Planetary Nebula IC 2003 Reveals Key Evolutionary Clues

Careful modelling of the thermal and ionization structure of planetary nebulae, based on observations from the Vainu Bappu Telescope in Kavalur, Tamil Nadu, India, has enabled astronomers to deepen their understanding of the formation and evolution of these unusual hydrogen-deficient stars.
Planetary nebulae are shells of gas and dust ejected by stars like our Sun after they exhaust the hydrogen and helium fuel in their cores—a fate our Sun is expected to face in approximately 5 billion years. As the star’s core contracts due to the lack of nuclear fusion, it heats up and emits intense far-ultraviolet radiation. In the past, these stars appeared planet-like when viewed through small telescopes, a resemblance that led to their name.
While most stars in this late phase of their lives produce core remnants surrounded by tiny residual hydrogen envelopes, about 25% of them exhibit a deficiency of hydrogen and are instead rich in helium on their surfaces. Some of these stars also display strong mass loss and emission lines of ionized helium, carbon, and oxygen, characteristics identified as Wolf-Rayet (WR) features.
IC 2003, a rare planetary nebula, features a hydrogen-deficient central remnant star with WR characteristics.

Although the evolutionary status of typical central stars of planetary nebulae is well-understood, the mechanisms behind the formation of hydrogen-poor stars remain largely unclear. The physical and chemical structures of the nebulae surrounding these stars provide valuable clues about their origin and evolution, making it essential to study their gas and dust in detail.
To investigate this further, astronomers from the Indian Institute of Astrophysics (IIA), an autonomous institute under the Department of Science and Technology, observed IC 2003 using the optical medium-resolution spectrograph (OMR) attached to the 2.3-meter Vainu Bappu Telescope at the Vainu Bappu Observatory in Kavalur, Tamil Nadu. “We also used ultraviolet spectra from the IUE satellite and broadband infrared fluxes from the IRAS satellite archives for this study,” said K. Khushbu, the lead author and Ph.D. student. These combined observations provided critical insights into the role of gas and dust in shaping the thermal structure of the nebula, ultimately enabling the team to derive precise parameters for the central star.
The models they used revealed that the nebula’s parameters, including the ionizing source’s mass and temperature, were significantly different from those predicted by dust-free models. “This study highlights the importance of dust grains in the thermal balance of ionized gas and helps explain the large temperature variations seen in nebulae, which are often key to resolving abundance discrepancies in astrophysical nebulae,” explained Prof. C. Muthumariappan, the supervisor and co-author of the study. “We used a one-dimensional dusty photo-ionization code, CLOUDY17.3, to simulate data from ultraviolet, optical, and infrared observations,” he added.
By modeling the photoelectric heating of the nebula caused by the dust grains, the researchers were able to replicate the thermal structure observed in the planetary nebula. “We even reproduced the large temperature gradient typically seen in nebulae with WR stars. Our determination of element abundances, such as helium, nitrogen, and oxygen, differs significantly from the values obtained empirically,” Khushbu noted.
The study also provided accurate grain size distributions within the nebula and highlighted the crucial role of photoelectric heating in explaining temperature variations. From their models, the researchers derived accurate values for the luminosity, temperature, and mass of the central star. They concluded that the star’s initial mass was 3.26 times that of the Sun, indicating it was a more massive star.
This research advances our understanding of the complex processes at work in the evolution of hydrogen-deficient stars and offers valuable insights into the origins of the unique features observed in planetary nebulae.
Space & Physics
MIT unveils an ultra-efficient 5G receiver that may supercharge future smart devices
A key innovation lies in the chip’s clever use of a phenomenon called the Miller effect, which allows small capacitors to perform like larger ones

A team of MIT researchers has developed a groundbreaking wireless receiver that could transform the future of Internet of Things (IoT) devices by dramatically improving energy efficiency and resilience to signal interference.
Designed for use in compact, battery-powered smart gadgets—like health monitors, environmental sensors, and industrial trackers—the new chip consumes less than a milliwatt of power and is roughly 30 times more resistant to certain types of interference than conventional receivers.
“This receiver could help expand the capabilities of IoT gadgets,” said Soroush Araei, an electrical engineering graduate student at MIT and lead author of the study, in a media statement. “Devices could become smaller, last longer on a battery, and work more reliably in crowded wireless environments like factory floors or smart cities.”
The chip, recently unveiled at the IEEE Radio Frequency Integrated Circuits Symposium, stands out for its novel use of passive filtering and ultra-small capacitors controlled by tiny switches. These switches require far less power than those typically found in existing IoT receivers.
A key innovation lies in the chip’s clever use of a phenomenon called the Miller effect, which allows small capacitors to perform like larger ones. This means the receiver achieves necessary filtering without relying on bulky components, keeping the circuit size under 0.05 square millimeters.

Traditional IoT receivers rely on fixed-frequency filters to block interference, but next-generation 5G-compatible devices need to operate across wider frequency ranges. The MIT design meets this demand using an innovative on-chip switch-capacitor network that blocks unwanted harmonic interference early in the signal chain—before it gets amplified and digitized.
Another critical breakthrough is a technique called bootstrap clocking, which ensures the miniature switches operate correctly even at a low power supply of just 0.6 volts. This helps maintain reliability without adding complex circuitry or draining battery life.
The chip’s minimalist design—using fewer and smaller components—also reduces signal leakage and manufacturing costs, making it well-suited for mass production.
Looking ahead, the MIT team is exploring ways to run the receiver without any dedicated power source—possibly by harvesting ambient energy from nearby Wi-Fi or Bluetooth signals.
The research was conducted by Araei alongside Mohammad Barzgari, Haibo Yang, and senior author Professor Negar Reiskarimian of MIT’s Microsystems Technology Laboratories.
Society
Ahmedabad Plane Crash: The Science Behind Aircraft Take-Off -Understanding the Physics of Flight
Take-off is one of the most critical phases of flight, relying on the precise orchestration of aerodynamics, propulsion, and control systems. Here’s how it works:

On June 12, 2025, a tragic aviation accident struck Ahmedabad, India when a regional passenger aircraft, Air India flight A1-171, crashed during take-off at Sardar Vallabhbhai Patel International Airport. According to preliminary reports, the incident resulted in over 200 confirmed casualties, including both passengers and crew members, and several others are critically injured. The aviation community and scientific world now turn their eyes not just toward the cause but also toward understanding the complex science behind what should have been a routine take-off.
How Do Aircraft Take Off?
Take-off is one of the most critical phases of flight, relying on the precise orchestration of aerodynamics, propulsion, and control systems. Here’s how it works:
1. Lift and Thrust
To leave the ground, an aircraft must generate lift, a force that counters gravity. This is achieved through the unique shape of the wing, called an airfoil, which creates a pressure difference — higher pressure under the wing and lower pressure above — according to Bernoulli’s Principle and Newton’s Third Law.
Simultaneously, engines provide thrust, propelling the aircraft forward. Most commercial jets use turbofan engines, which accelerate air through turbines to generate power.
2. Critical Speeds
Before takeoff, pilots calculate critical speeds:
- V1 (Decision Speed): The last moment a takeoff can be safely aborted.
- Vr (Rotation Speed): The speed at which the pilot begins to lift the nose.
- V2 (Takeoff Safety Speed): The speed needed to climb safely even if one engine fails.
If anything disrupts this process — like bird strikes, engine failure, or runway obstructions — the results can be catastrophic.

Environmental and Mechanical Challenges
Factors like wind shear, runway surface condition, mechanical integrity, or pilot error can interfere with safe take-off. Investigators will be analyzing these very aspects in the Ahmedabad case.
The Bigger Picture
Take-off accounts for a small fraction of total flight time but is disproportionately associated with accidents — approximately 14% of all aviation accidents occur during take-off or initial climb.
Space & Physics
MIT claims breakthrough in simulating physics of squishy, elastic materials
In a series of experiments, the new solver demonstrated its ability to simulate a diverse array of elastic behaviors, ranging from bouncing geometric shapes to soft, squishy characters

Researchers at MIT claim to have unveiled a novel physics-based simulation method that significantly improves stability and accuracy when modeling elastic materials — a key development for industries spanning animation, engineering, and digital fabrication.
In a series of experiments, the new solver demonstrated its ability to simulate a diverse array of elastic behaviors, ranging from bouncing geometric shapes to soft, squishy characters. Crucially, it maintained important physical properties and remained stable over long periods of time — an area where many existing methods falter.
Other simulation techniques frequently struggled in tests: some became unstable and caused erratic behavior, while others introduced excessive damping that distorted the motion. In contrast, the new method preserved elasticity without compromising reliability.
“Because our method demonstrates more stability, it can give animators more reliability and confidence when simulating anything elastic, whether it’s something from the real world or even something completely imaginary,” Leticia Mattos Da Silva, a graduate student at MIT’s Department of Electrical Engineering and Computer Science, said in a media statement.
Their study, though not yet peer-reviewed or published, will be presented at the August proceedings of the SIGGRAPH conference in Vancouver, Canada.
While the solver does not prioritize speed as aggressively as some tools, it avoids the accuracy and robustness trade-offs often associated with faster methods. It also sidesteps the complexity of nonlinear solvers, which are commonly used in physics-based approaches but are often sensitive and prone to failure.
Looking ahead, the research team aims to reduce computational costs and broaden the solver’s applications. One promising direction is in engineering and fabrication, where accurate elastic simulations could enhance the design of real-world products such as garments, medical devices, and toys.
“We were able to revive an old class of integrators in our work. My guess is there are other examples where researchers can revisit a problem to find a hidden convexity structure that could offer a lot of advantages,” Mattos Da Silva added.
The study opens new possibilities not only for digital content creation but also for practical design fields that rely on predictive simulations of flexible materials.
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