Αστρονομική Εικόνα της Ημέρας από τη NASA

Προηγούμενες Αστρονομικές Εικόνες της Ημέρας από τη NASA

Animation: Black Hole Destroys Star

16/06/2024

What happens if a star gets too close to a black hole? The black hole can rip it apart -- but how? It's not the high gravitational attraction itself that's the problem -- it's the difference in gravitational pull across the star that creates the destruction. In the featured animated video illustrating this disintegration, you first see a star approaching the black hole. Increasing in orbital speed, the star's outer atmosphere is ripped away during closest approach. Much of the star's atmosphere disperses into deep space, but some continues to orbit the black hole and forms an accretion disk. The animation then takes you into the accretion disk while looking toward the black hole. Including the strange visual effects of gravitational lensing, you can even see the far side of the disk. Finally, you look along one of the jets being expelled along the spin axis. Theoretical models indicate that these jets not only expel energetic gas, but also create energetic neutrinos -- one of which may have been seen recently on Earth. Almost Hyperspace: Random APOD Generator

Prominences and Filaments on the Active Sun

15/06/2024

This colorized and digitally sharpened image of the Sun is composed of frames recording emission from hydrogen atoms in the solar chromosphere on May 15. Approaching the maximum of solar cycle 25, a multitude of planet-dwarfing active regions and twisting, snake-like solar filaments are seen to sprawl across the surface of the active Sun. Suspended in the active regions' strong magnetic fields, the filaments of plasma lofted beyond the Sun's edge appear as bright solar prominences. The large prominences seen near 4 o'clock, and just before 9 o'clock around the solar limb are post flare loops from two powerful X-class solar flares that both occurred on that day. In fact, the 4 o'clock prominence is associated with the monster active region AR 3664 just rotating off the Sun's edge.

RCW 85

14/06/2024

From the 1960 astronomical catalog of Rodgers, Campbell and Whiteoak, emission region RCW 85 shines in southern night skies between bright stars Alpha and Beta Centauri. About 5,000 light years distant, the hazy interstellar cloud of glowing hydrogen gas and dust is faint. But detailed structures along well-defined rims within RCW 85 are traced in this cosmic skyscape composed of 28 hours of narrow and broadband exposures. Suggestive of dramatic shapes in other stellar nurseries where natal clouds of gas and dust are sculpted by energetic winds and radiation from newborn stars, the tantalizing nebula has been called the Devil's Tower. This telescopic frame would span around 100 light-years at the estimated distance of RCW 85.

Messier 66 Close Up

13/06/2024

Big, beautiful spiral galaxy Messier 66 lies a mere 35 million light-years away. The gorgeous island universe is about 100 thousand light-years across, similar in size to the Milky Way. This Hubble Space Telescope close-up view spans a region about 30,000 light-years wide around the galactic core. It shows the galaxy's disk dramatically inclined to our line-of-sight. Surrounding its bright core, the likely home of a supermassive black hole, obscuring dust lanes and young, blue star clusters sweep along spiral arms dotted with the tell-tale glow of pinkish star forming regions. Messier 66, also known as NGC 3627, is the brightest of the three galaxies in the gravitationally interacting Leo Triplet.

Aurora over Karkonosze Mountains

12/06/2024

It was the first time ever. At least, the first time this photographer had ever seen aurora from his home mountains. And what a spectacular aurora it was. The Karkonosze Mountains in Poland are usually too far south to see any auroras. But on the amazing night of May 10 - 11, purple and green colors lit up much of the night sky, a surprising spectacle that also appeared over many mid-latitude locations around the Earth. The featured image is a composite of six vertical exposures taken during the auroral peak. The futuristic buildings on the right are part of a meteorological observatory located on the highest peak of the Karkonosze Mountains. The purple color is primarily due to Sun-triggered, high-energy electrons impacting nitrogen molecules in Earth's atmosphere. Our Sun is reaching its maximum surface activity over the next two years, and although many more auroras are predicted, most will occur over regions closer to the Earth's poles.

Colorful Stars and Clouds near Rho Ophiuchi

11/06/2024

Why is the sky near Antares and Rho Ophiuchi so colorful, yet dusty? The colors result from a mixture of objects and processes. Fine dust -- illuminated by starlight -- produces blue reflection nebulae. Gaseous clouds whose atoms are excited by ultraviolet starlight produce reddish emission nebulae. Backlit dust clouds block starlight and so appear dark. Antares, a red supergiant and one of the brighter stars in the night sky, lights up the yellow-red clouds on the upper right of the featured image. The Rho Ophiuchi star system lies at the center of the blue reflection nebula on the left, while a different reflection nebula, IC 4605, lies just below and right of the image center. These star clouds are even more colorful than humans can see, emitting light across the electromagnetic spectrum. Open Science: Browse 3,400+ codes in the Astrophysics Source Code Library

Sh2-132: The Lion Nebula

10/06/2024

Is the Lion Nebula the real ruler of the constellation Cepheus? This powerful feline appearing nebula is powered by two massive stars, each with a mass over 20 times greater than our Sun. Formed from shells of ionized gas that have expanded, the nebula's energetic matter not only glows, but is dense enough to contract gravitationally and form stars. The angular size of the Lion Nebula, officially named Sh2-132, is slightly greater than that of the full moon. The gaseous iconic region resides about 10,000 light years away in a constellation named after the King of Aethopia in Greek mythology. Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)

How to Identify that Light in the Sky

09/06/2024

What is that light in the sky? The answer to one of humanity's more common questions may emerge from a few quick observations. For example -- is it moving or blinking? If so, and if you live near a city, the answer is typically an airplane, since planes are so numerous and so few stars and satellites are bright enough to be seen over the glare of artificial city lights. If not, and if you live far from a city, that bright light is likely a planet such as Venus or Mars -- the former of which is constrained to appear near the horizon just before dawn or after dusk. Sometimes the low apparent motion of a distant airplane near the horizon makes it hard to tell from a bright planet, but even this can usually be discerned by the plane's motion over a few minutes. Still unsure? The featured chart gives a sometimes-humorous but mostly-accurate assessment. Dedicated sky enthusiasts will likely note -- and are encouraged to provide -- polite corrections. Chart translations: Italian, German, Latvian, Persian, Polish, Slovenian, Spanish, and Turkish

Η Αστρονομική Εικόνα της Ημέρας από τη NASA

Rigel and the Witch Head Nebula

31/10/2024