Star – HOPS‑315

Source: TH

Context: Astronomers have, for the first time, captured the condensation of solid rock from vapor around a newborn star — HOPS‑315 — using the James Webb Space Telescope and ALMA, revealing the earliest stage of planet formation.

About Star – HOPS‑315:

What is HOPS‑315?

• Newborn Protostar: HOPS‑315 is a young, still-forming star located in the Orion molecular cloud, surrounded by a dense protoplanetary disc of gas and dust.

• Tilted Disc Advantage: Its disc is uniquely inclined, allowing Earth-based telescopes a rare view deep into its planet-forming interior.

• Key Observations: James Webb Space Telescope (JWST) detected strong silicon monoxide gas emissions (~470 K) and crystalline silicates within 2.2 AU of the star — the region where rocky planets may eventually form. ALMA identified cooler surrounding gases and confirmed the absence of slow-moving SiO, indicating the crystals were embedded in the rising disc atmosphere rather than in stellar outflows.

• James Webb Space Telescope (JWST) detected strong silicon monoxide gas emissions (~470 K) and crystalline silicates within 2.2 AU of the star — the region where rocky planets may eventually form.

• ALMA identified cooler surrounding gases and confirmed the absence of slow-moving SiO, indicating the crystals were embedded in the rising disc atmosphere rather than in stellar outflows.

• Crystallisation Process: At around 1 AU from HOPS‑315, computer simulations and real data suggest dust vaporised at ~1300 K, then re-condensed into minerals like forsterite, enstatite, and silica — similar to those in ancient Earth meteorites.

• First-Ever Direct Evidence: This is the first observational proof of rock vapor turning into solid crystals in another star system, capturing the earliest step of rocky planet formation.

Significance of the Discovery:

• Planet Formation Genesis: Offers direct insight into how rocky planets like Earth begin forming from vaporized rock.

• Solar System Parallel: Mimics early processes from our own Solar System, bridging observational gaps in planetary evolution.

• Rare Astronomical Window: Tilt of the disc allowed an unprecedented look at inner disc chemistry — rarely accessible in other systems.

• Interstellar Mineral Match: Mineral types mirror chondritic meteorite inclusions, hinting at universal chemistry in rocky planet birth.