February 4, 2000
The universe does not repeat itself. Every sunrise is unique, every snowflake singular, and every birthday yours alone.
X-Ray Stars Of Orion
Birthday · February 4, 2000
A little universe, just for you
Your date.
Ready to give.
Free PNG · 1080 × 1350 · No account needed
Image rights and credit requirements apply when sharing or reusing imagery.
Date & occasion only
Change the year
APOD published February 4, 2000. Full image credits are on the original APOD entry below. A publication-date match, not a photo taken on your date. Independent of NASA.
The stars of Orion shine brightly in northern winter skies where the constellation harbors the closest large stellar nursery, the Great Nebula of Orion, a mere 1500 light-years away. In fact, the apparently bright clump of stars near the center of this Chandra X-ray telescope picture of a portion of the nebula are the massive stars of the Trapezium - the young star cluster which powers much of the nebula's visible-light glow. But the sheer number of other stars seen in this X-ray image, which spans about 10 light-years, has surprised and delighted astronomers and this picture was recently touted as the richest field of X-ray sources ever recorded in a single observation. The picture does dramatically illustrate that young stars are prodigious sources of X-rays, thought to be produced in hot stellar coronas and surface flares in a young star's strong magnetic field. Our middle-aged Sun itself was probably thousands of times brighter in X-rays when, like the Trapezium stars, it was only a few million years old. The dark lines through the image are instrumental artifacts.