Αστρονομική Εικόνα της Ημέρας από τη NASA

Προηγούμενες Αστρονομικές Εικόνες της Ημέρας από τη NASA

GK Per: Nova and Planetary Nebula

30/04/2024

The star system GK Per is known to be associated with only two of the three nebulas pictured. At 1500 light years distant, Nova Persei 1901 (GK Persei) was the second closest nova yet recorded. At the very center is a white dwarf star, the surviving core of a former Sun-like star. It is surrounded by the circular Firework nebula, gas that was ejected by a thermonuclear explosion on the white dwarf's surface -- a nova -- as recorded in 1901. The red glowing gas surrounding the Firework nebula is the atmosphere that used to surround the central star. This gas was expelled before the nova and appears as a diffuse planetary nebula. The faint gray gas running across is interstellar cirrus that seems to be just passing through coincidently. In 1901, GK Per's nova became brighter than Betelgeuse. Similarly, star system T CrB is expected to erupt in a nova later this year, but we don't know exactly when nor how bright it will become.

Comet, Planet, Moon

29/04/2024

Three bright objects satisfied seasoned stargazers of the western sky just after sunset earlier this month. The most familiar was the Moon, seen on the upper left in a crescent phase. The rest of the Moon was faintly visible by sunlight first reflected by the Earth. The bright planet Jupiter, the largest planet in the Solar System, is seen to the upper left. Most unusual was Comet 12P/Pons-Brooks, below the Moon and showing a stubby dust tail on the right but an impressive ion tail extending upwards. The featured image, a composite of several images taken consecutively at the same location and with the same camera, was taken near the village of Llers, in Spain's Girona province. Comet Pons-Brooks passed its closest to the Sun last week and is now dimming as it moves into southern skies and returns to the outer Solar System. Almost Hyperspace: Random APOD Generator

Rings Around the Ring Nebula

28/04/2024

The Ring Nebula (M57) is more complicated than it appears through a small telescope. The easily visible central ring is about one light-year across, but this remarkably deep exposure - a collaborative effort combining data from three different large telescopes - explores the looping filaments of glowing gas extending much farther from the nebula's central star. This composite image includes red light emitted by hydrogen as well as visible and infrared light. The Ring Nebula is an elongated planetary nebula, a type of nebula created when a Sun-like star evolves to throw off its outer atmosphere and become a white dwarf star. The Ring Nebula is about 2,500 light-years away toward the musical constellation Lyra. Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)

All Sky Moon Shadow

27/04/2024

If the Sun is up but the sky is dark and the horizon is bright all around, you might be standing in the Moon's shadow during a total eclipse of the Sun. In fact, the all-sky Moon shadow shown in this composited panoramic view was captured from a farm near Shirley, Arkansas, planet Earth. The exposures were made under clear skies during the April 8 total solar eclipse. For that location near the center line of the Moon's shadow track, totality lasted over 4 minutes. Along with the solar corona surrounding the silhouette of the Moon planets and stars were visible during the total eclipse phase. Easiest to see here are bright planets Venus and Jupiter, to the lower right and upper left of the eclipsed Sun.

Regulus and the Dwarf Galaxy

26/04/2024

In northern hemisphere spring, bright star Regulus is easy to spot above the eastern horizon. The alpha star of the constellation Leo, Regulus is the spiky star centered in this telescopic field of view. A mere 79 light-years distant, Regulus is a hot, rapidly spinning star that is known to be part of a multiple star system. Not quite lost in the glare, the fuzzy patch just below Regulus is diffuse starlight from small galaxy Leo I. Leo I is a dwarf spheroidal galaxy, a member of the Local Group of galaxies dominated by our Milky Way Galaxy and the Andromeda Galaxy (M31). About 800 thousand light-years away, Leo I is thought to be the most distant of the known small satellite galaxies orbiting the Milky Way. But dwarf galaxy Leo I has shown evidence of a supermassive black hole at its center, comparable in mass to the black hole at the center of the Milky Way.

NGC 604: Giant Stellar Nursery

25/04/2024

Located some 3 million light-years away in the arms of nearby spiral galaxy M33, giant stellar nursery NGC 604 is about 1,300 light-years across. That's nearly 100 times the size of the Milky Way's Orion Nebula, the closest large star forming region to planet Earth. In fact, among the star forming regions within the Local Group of galaxies, NGC 604 is second in size only to 30 Doradus, also known as the Tarantula Nebula in the Large Magellanic Cloud. Cavernous bubbles and cavities in NGC 604 fill this stunning infrared image from the James Webb Space Telescope's NIRCam. They are carved out by energetic stellar winds from the region's more than 200 hot, massive, young stars, all still in early stages of their lives.

Dragon's Egg Bipolar Emission Nebula

24/04/2024

How did a star form this beautiful nebula? In the middle of emission nebula NGC 6164 is an unusually massive star. The central star has been compared to an oyster's pearl and an egg protected by the mythical sky dragons of Ara. The star, visible in the center of the featured image and catalogued as HD 148937, is so hot that the ultraviolet light it emits heats up gas that surrounds it. That gas was likely thrown off from the star previously, possibly the result of a gravitational interaction with a looping stellar companion. Expelled material might have been channeled by the magnetic field of the massive star, in all creating the symmetric shape of the bipolar nebula. NGC 6164 spans about four light years and is located about 3,600 light years away toward the southern constellation Norma. New Mirror: APOD now available via WhatsApp

Contrail Shadow X

23/04/2024

What created this giant X in the clouds? It was the shadow of contrails. When airplanes fly, humid engine exhaust may form water droplets that might freeze in Earth's cold upper atmosphere. These persistent streams of water and ice scatter light from the Sun above and so appear bright. These contrails cast long shadows. That was just the case over Istanbul, Türkiye, earlier this month. Contrails occur all over planet Earth and, generally, warm the Earth when the trap infrared light but cool the Earth when they efficiently reflect sunlight. The image was taken by a surprised photographer in the morning on the way to work.

Η Αστρονομική Εικόνα της Ημέρας από τη NASA

Spiral Galaxy NGC 6744

01/11/2024