Posts Tagged ‘Hercules’

Credit: NASA, ESA, and The Hub­ble Her­itage Team (STScI/AURA)

Col­or­ful shapes and lines play in this NASA Hub­ble Space Tele­scope image of the glow­ing plan­e­tary neb­ula IC 4593. Plan­e­tary neb­ula have noth­ing to do with plan­ets. In the 17th and 18th cen­turies, astronomers peer­ing through small tele­scopes look­ing for plan­ets would find objects that resem­bled plan­ets. Astronomers now know that these neb­ula are the last remains of dying Sun-like stars. As a star reaches the end of its life and the hydro­gen fuel needed to sus­tain fusion in its core runs out, the star expands into a red giant. Even­tu­ally, how­ever, the star col­lapses back on itself. This increases the tem­per­a­ture at its core and it explodes. Most of the star’s mate­r­ial is cat­a­pulted into space, form­ing a bub­ble around the star. This doesn’t hap­pen all at once but in stages.

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