NASAのインスタグラム(nasa) - 12月18日 01時32分

Just in time for the holidays, a festive Hubble Space Telescope image that resembles a holiday wreath made of sparkling lights! The bright southern hemisphere star RS Puppis, at the center of the image, is swaddled in a gossamer cocoon of reflective dust illuminated by the glittering star. The super star is ten times more massive than our sun and 200 times larger.

RS Puppis rhythmically brightens and dims over a six-week cycle. It is one of the most luminous in the class of so-called Cepheid variable stars. Its average intrinsic brightness is 15,000 times greater than our sun’s luminosity.

The nebula flickers in brightness as pulses of light from the Cepheid propagate outwards. Hubble took a series of photos of light flashes rippling across the nebula in a phenomenon known as a "light echo." Even though light travels through space fast enough to span the gap between Earth and the moon in a little over a second, the nebula is so large that reflected light can actually be photographed traversing the nebula.

Image Credit: NASA/ESA/Hubble Heritage (STScI/AURA)-Hubble/Europe Collab.

#nasa #space #hubble #galaxy #hst #universe #esa #nebula #earth #light #science #astronomy

[BIHAKUEN]UVシールド(UVShield)

>> 飲む日焼け止め！「UVシールド」を購入する