Reading dust, rings, gaps, and asymmetry around stars, while distinguishing observations from possible planetary explanations.
Exozodiacal dust makes an Earth-like planet harder to detect by adding background light and sometimes confusing structure near the planet’s apparent position. The main problem is not an opaque screen. A very thin dust cloud can still matter because a reflected-light planet is extraordinarily faint. Three obstacles that need different solutions Obstacle What it does … Read more
A debris disk can look deceptively simple from a distance: a faint ring of dust surrounding a star, something like a scaled-up version of the Solar System’s asteroid belt or Kuiper Belt. But when astronomers observe these disks with instruments such as the Atacama Large Millimeter/submillimeter Array (ALMA), the Hubble Space Telescope, and the James … Read more
A warm debris disk is a population of dust around a star whose thermal emission is associated with relatively warm, inner-system material. Around a Sun-like star, it can reveal collisions or delivery of small bodies into regions closer to the star than a cold outer belt. “Warm” is an observational description, not a fixed temperature … Read more
Astronomers usually establish circumstellar dust by showing that a star has more infrared emission than its photosphere can explain, then testing whether that excess really belongs to the star. A resolved ring is a richer result, but many disks are first detected without a photograph of their shape. Start with a prediction, not an attractive … Read more