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Keldura Daily · Science & Space

Three new views of how the cosmos moves, recycles and grows

Satellite eclipse tracking, unexpected stellar-debris structures and a possible new class of early-universe object offer unusually visual explanations of cosmic processes across radically different scales.

The field note

4 sources · 4 items
  1. MTG-I1 observes Europe and northern Africa from geostationary orbit about 36,000 km above Earth, allowing it to…
  2. The satellite recorded the Moon’s shadow converging with Europe’s advancing twilight as dusk fell.[1]
  3. Totality followed a narrow track, but a partial eclipse was visible from northern Canada and the Nordic countri…
Story 012 sources

How did a weather satellite track Europe’s total eclipse?

MTG-I1 images captured the path of totality crossing Greenland and Iceland before reaching northeastern Portugal and Spain, where mainland totality lasted only a few minutes.[1] Ground-level photographs simultaneously revealed the solar corona, normally overwhelmed by the bright solar disc, as the eclipse passed from Greenland toward Europe.[4]

Why it matters

The event demonstrates how a geostationary weather satellite can provide a continuous, continent-scale view of an eclipse while observers inside the narrow path record details of the Sun’s atmosphere.[1][4]

Key insights

  • MTG-I1 observes Europe and northern Africa from geostationary orbit about 36,000 km above Earth, allowing it to keep the same region continuously in view.[1]
  • The satellite recorded the Moon’s shadow converging with Europe’s advancing twilight as dusk fell.[1]
  • Totality followed a narrow track, but a partial eclipse was visible from northern Canada and the Nordic countries to the western African coast as far south as Sierra Leone and Liberia.[1]
Story 022 sources

What could a “black hole star” actually be?

The object MoM-BH*-1 appeared in the early universe as a red source roughly 100 billion times more energetic than any known star can physically produce.[7] Simulations most closely matched a central black hole about 100,000 times the Sun’s mass surrounded by a dense, star-like hydrogen envelope roughly the size of the solar system.[7][8]

Why it matters

If the interpretation holds, this previously unobserved configuration could help explain the numerous “little red dots” found in JWST imagery and clarify how massive black holes operated only a few hundred million years after the Big Bang.[7][8]

Key insights

  • Unlike an ordinary star, the proposed object would be powered by material accreting onto a black hole rather than by nuclear fusion.[7]
  • Its spectrum contains almost no metal signatures beyond hydrogen and helium and displays an exceptionally deep Balmer break associated with dense, photon-absorbing gas.[8]
  • Researchers reached the model after ordinary stellar explanations could not reproduce the observed luminosity and simulations incorporating an accreting black hole produced the closest match.[7][8]
  • MoM-BH*-1 outshines its host galaxy, but researchers say other, dimmer JWST red dots are also consistent with the same general model.[7][8]

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