Billions of years ago, our young sun may have consumed a planet several times the mass of Earth, and the chemical fingerprints of that ancient collision could still be detectable deep inside the star today, according to new research published in the journal Monthly Notices of the Royal Astronomical Society.

The study, authored by Mutlu Yildiz, an astronomer at Ege University in Turkey, presents a model suggesting the sun engulfed a “super-Earth-mass” planet — one estimated at five to 10 times the mass of Earth — early in its history. The finding offers a possible explanation for two longstanding puzzles in solar science that conventional models have struggled to fully resolve.

“Our new study suggests that a planet several times more massive than Earth may have fallen into the young Sun and left a lasting chemical imprint deep inside it,” Yildiz said in a statement.

Two mysteries in search of a common cause

The research grew out of separate, seemingly unrelated problems in solar astronomy. The first involves the sun’s convection zone, the star’s outermost layer, where standard models have consistently had difficulty matching actual observational data. The second concerns lithium, an element that should be among the earliest to survive largely intact through a star’s evolution, yet the sun’s surface shows a notable lithium deficiency compared with other stars of similar size and age.

Yildiz set out to determine whether these two unrelated anomalies might share a single origin. “We were interested [in] whether these problems might have a common origin in the early chemical history of the Sun,” Yildiz said. “Since planets are made of material that is chemically different from the gas in the disc, we wondered whether the early engulfment of a planet could have left a chemical signature inside the young Sun.”

Modeling a cosmic collision

To test the idea, Yildiz used an open-source stellar evolution module to run through a wide range of possible accretion scenarios, essentially testing different combinations of events that could have produced the sun as it appears today. Among the scenarios tested, the one that best matched observed data involved the young sun consuming a super-Earth-mass planet.

The resulting numbers lined up closely with existing measurements of the sun’s internal structure and its surface lithium content, lending additional weight to the scenario. Yildiz noted that the precision of the result came as something of a surprise even to him.

“We thought planetary engulfment might affect the solar structure but did not expect the calculations to converge on such a specific super-Earth mass range,” Yildiz said. “That was one of the most interesting outcomes of the study.”

A possible clue to the makeup of our solar system

Beyond addressing the lithium and convection-zone puzzles, the engulfment scenario may also help explain another peculiar feature of our solar system: the conspicuous absence of super-Earth-sized planets, a category common in many other star systems observed by astronomers. If an early super-Earth once orbited close to the young sun and was ultimately pulled in and destroyed, its disappearance could account for why no planet of that size exists in our solar system today.

Evidence, not proof

Yildiz was careful to frame the findings as evidence supporting a plausible scenario rather than definitive confirmation that the event occurred. In the paper, he wrote that the calculations “strengthen the physical plausibility” of the sun having swallowed a super-Earth-sized planet, while stopping short of claiming certainty. The paper describes the scenario as a promising candidate for the “key missing ingredient” that has been absent from existing solar and stellar models.

Yildiz said the next phase of research will focus on searching for more direct, independently verifiable evidence of the ancient engulfment buried within the sun’s structure. “Our paper asks whether the Sun itself could still carry observable evidence that such an engulfment actually happened, and we believe it could,” Yildiz said. “The next step is to see if these fingerprints can be independently detected.”

Why planetary engulfment matters to astronomers

Stellar engulfment of planets is not considered a rare phenomenon in the broader universe. Astronomers have observed direct evidence of stars consuming nearby planets in other systems, and theoretical models suggest such events are a natural, if violent, part of how planetary systems evolve and stabilize over billions of years. Planets that form too close to their host star, or whose orbits become unstable over time due to gravitational interactions with other bodies, can spiral inward and eventually be pulled apart and absorbed by the star’s immense gravity and heat.

What makes the sun’s case distinctive, according to the new research, is the possibility that this kind of event left behind detectable chemical evidence that has persisted for billions of years, offering scientists a potential window into the sun’s earliest, most chaotic period of formation.

The study adds to a growing body of research using increasingly sophisticated stellar modeling techniques to probe the sun’s distant past, a period that remains difficult to study directly given how much the star’s structure and composition have evolved since its formation roughly 4.6 billion years ago. If future observational work is able to confirm the specific chemical signatures Yildiz’s model predicts, it could mark a significant step toward resolving decades-old questions about the sun’s internal chemistry and, more broadly, about how the current architecture of our solar system came to be.

For now, the case remains open, but the new modeling gives astronomers a specific and testable hypothesis to pursue in the search for what really happened inside our solar system’s earliest, most turbulent chapter.

The Securities and Exchange Board of India (Sebi) has announced the successful launch of Demat 2.0, a pilot project for tokenised corporate bonds that seeks to test a new way of issuing, holding, trading and settling bonds in India. The announcement was made jointly by RBI Governor Sanjay Malhotra and Sebi Chairman Tuhin Kanta Pandey at the Global Fintech Fest in Mumbai.

For investors in corporate bonds, the launch of Sebi’s Demat 2.0 pilot could change how bond transactions are settled and how payments are received. The tokenised bond system is designed to enable faster settlement, quicker access to funds from secondary-market transactions and automated processing of interest and redemption payments.

What is Demat 2.0?

Demat 2.0 is a new market infrastructure developed to test the tokenisation of corporate bonds.

Under the system, a bond is created as a digital token on a distributed ledger. The ledger is a shared electronic record maintained simultaneously by market infrastructure institutions using distributed ledger technology (DLT), while the ledger is owned by the depositories.

Demat 2.0 is connected to the RBI’s wholesale central bank digital currency (CBDC), or e-rupee, through the Unified Market Interface.

This enables atomic settlement, where the bond and money move instantaneously.
For investors, this means the securities and corresponding funds can move at the same time, removing the gap between the completion of the two sides of a transaction.

Faster access to funds after selling bonds

One of the key changes for investors is the time taken to receive money from secondary-market transactions.

Sebi said investors can receive funds immediately in secondary-market transactions under Demat 2.0. Under the earlier process, funds generally took two to three days to be received.

The shorter settlement timeline means funds from a completed secondary-market transaction can be deployed elsewhere immediately.

Interest and redemption payments can be automated

Demat 2.0 also seeks to change how investors receive interest and redemption payments on their bonds.

Currently, the issuer or its registrar needs to obtain the list of bondholders from the depositories, calculate the amount payable to each holder and route the payments separately through the banking channel.

Under Demat 2.0, bondholder details are visible to authorised institutions on the shared ledger. Smart contracts — instructions written into the ledger that execute automatically — can trigger interest and redemption payments.

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Sebi said payments in e-rupee can reach bondholders’ CBDC wallets on the due date.

For investors, this means interest and redemption payments can be processed automatically through the new infrastructure.

Settlement risk eliminated

Atomic settlement is another feature that Sebi has highlighted.

Under the system, the bond and money move instantaneously. Sebi said this eliminates settlement risk, as one side of the transaction does not remain pending after the other side has been completed.

Three issuers have raised Rs 1,025 crore

Three companies have issued tokenised bonds so far under the pilot, raising a combined Rs 1,025 crore.

REC was the first issuer on September 7, 2026. The public sector NBFC raised Rs 500 crore from 18 investors.

L&T was the second issuer on September 9, raising Rs 500 crore from four investors.

IIFL was the third issuer on September 9, raising Rs 25 crore from one investor.

The pilot is being implemented in phases. The first phase is currently focused on issuances. Later phases will extend the system to buying and selling tokenised bonds through existing request-for-quote (RFQ) platforms and eventually to retail investor access.

What Demat 2.0 means for investors

From an investor’s perspective, the pilot introduces several changes to the way corporate bond transactions and payments can be handled.

Immediate secondary-market funds: Investors can receive funds immediately from secondary-market transactions, compared with the earlier two-to-three-day timeline.

Simultaneous settlement: Atomic settlement allows the bond and money to move instantaneously.

Lower settlement risk: Sebi said settlement risk is eliminated because the two sides of the transaction do not remain pending separately.

Automated interest payments: Smart contracts can trigger interest payments on the due date.

Automated redemption: Redemption payments can also be triggered through smart contracts.

Direct e-rupee payments: Interest and redemption payments can reach bondholders’ CBDC wallets in e-rupee on the due date.

India’s approach to tokenised bonds

Sebi said tokenisation pilots and commercial launches have taken place globally, including Project Helvetia III in Switzerland and Project Evergreen in Hong Kong. Tokenised treasury bonds and bonds from BlackRock, JPMorgan and the Asian Infrastructure Investment Bank are also among the global examples cited by Sebi.

According to Sebi, tokenisation in these cases has largely been undertaken by individual issuers on separate platforms.

India’s approach under Demat 2.0 is to issue corporate bonds natively on a distributed ledger, with the record of ownership held by statutory depositories and funds settled in central bank digital currency within the existing regulated market infrastructure.

For bond investors, the pilot is currently focused on issuance, while future phases are expected to bring tokenised bonds into secondary-market buying and selling and eventually extend access to retail investors.

This article has been written by Kumar Gaurav, who is not a SEBI-registered Research Analyst or an Investment Adviser. Gaurav and his/her ‘relative(s)’ (as defined under Section 2(77) of the Companies Act, 2013) do not hold any financial interest in the companies mentioned in this article as of the date of publication. The views/recommendations mentioned in this article, wherever applicable, are those of the respective SEBI-registered Research Analyst/brokerage and have been reproduced/reported with due attribution. They should not be construed as the views or recommendations of The Economic Times Digital or the journalist. Readers are advised to consider the original research report and make their investment decisions based on their own assessment.