Imagem Astronómica do Dia

Witness XZ Andromedae Wink

09/09/2026

Explicação: Is this star winking at us? The central object in today’s animation is not one but two stars. XZ Andromedae, indicated by the bold lines, is an Algol-type eclipsing binary with a nearly edge-on orbit from Earth’s perspective. The bottom light curve shows the amount of light from the system dim and brighten as the cooler star eclipses its hotter, brighter companion. Analysis of several XZ Andromedae light curves indicates there may be two other stars orbiting the system. This particular light curve was created with Citizen Astronomy, an open-source software for differential photometry. The software takes the difference in brightness between a target and comparison star and traces its behavior over time. This technique reduces most variations from the instrument and Earth’s atmosphere. In addition to eclipsing binaries, this analysis is useful for studying transiting exoplanets, accreting black holes, supernovae, and many more time-varying astronomical phenomena. Astrophotographers: try it out on your own data!

Hubble: Decagon Around Saturn's South Pole

08/09/2026

Explicação: Why are Saturn’s poles geometric? Saturn’s North Pole has been known to be surrounded by a hexagonal (6 sides) cloud since discovery in 1987 in data taken by NASA’s Voyager spacecrafts, which quickly flew past the ringed world in the early 1980s. Now, recent observations of Saturn by the Hubble Space Telescope reveal a slightly different geometric cloud pattern around the South Pole: a decagon (10 sides). The geometric boundaries are possibly caused by waves when the fast-moving gas away from the poles interacts with slower-moving gas closer to the poles. In the featured image composite by the Hubble taken last year, the South Pole of Saturn is marked by an X and surrounded by bands of circulating clouds. The decagon appears most prominent in the dark inner regions. The northern hexagon has proven stable for over 40 years, while the stability of the southern decagon will surely remain a topic of research. APOD's main NASA site is moving: From apod.nasa.gov to science.nasa.gov/apod

The Pelican Nebula in Gas, Dust, and Stars

07/09/2026

Explicação: The Pelican Nebula is slowly being transformed. IC 5070 (an official designation) is divided from the larger North America Nebula by a molecular cloud filled with dark dust. The deep featured picture from Utah, USA incorporates 25 hours of exposure and brings out great details of this filamentary dust. The Pelican Nebula receives much study because it is a particularly active mix of star formation and evolving gas clouds. The light from young energetic stars is slowly transforming the cold gas to hot gas, with the advancing boundary between the two, known as an ionization front, visible in bright orange on the upper right. Particularly dense tentacles of cold gas remain. Millions of years from now, the Pelican Nebula, bounded by dark nebula LDN 935, might no longer be known as the Pelican, as the balance and placement of stars and gas will surely leave something that appears completely different. APOD's main NASA site is moving: From apod.nasa.gov to science.nasa.gov/apod

Créditos: Mark Killion

Pluto in Enhanced Color

06/09/2026

Explicação: Pluto is more colorful than we can see. Color data and high-resolution images of our Solar System's most famous dwarf planet, taken by the robotic New Horizons spacecraft during its flyby in 2015 July, have been digitally combined to give an enhanced-color view of this ancient world sporting an unexpectedly young surface. The featured enhanced color image is not only esthetically pretty but scientifically useful, making surface regions of differing chemical composition visually distinct. For example, the light-colored heart-shaped Tombaugh Regio on the lower right is clearly shown here to be divisible into two regions that are geologically different, with the leftmost lobe, Sputnik Planitia, also appearing unusually smooth. After Pluto, New Horizons continued on, shooting past asteroid Arrokoth in 2019 with enough speed to escape our Solar System completely.

Chasing the Moon's Shadow

05/09/2026

Explicação: Chasing the shadow of a New Moon, NASA’s WB-57F high altitude research aircraft took to the skies off the coast of Iceland on August 12 to observe a total solar eclipse. At 50,000 feet the aircraft was piloted along the precisely determined path of totality to maximize its time in the Moon’s shadow. A suite of high-resolution cameras on board was able to record eclipse data from above the clouds, dust, and atmospheric water vapor that interfere with observations made closer to the ground. This view from the cockpit, taken from an inflight video, captures the solar corona emerging at the beginning of totality. The sky appears dark in the shadow of the Moon. Venus is shining left of center in the video frame, while Jupiter and Mercury are just visible to the right of the eclipsed Sun. But the sky is bright along the distant horizon below, beyond the reach of the Moon's shadow. APOD's main NASA site is moving: From apod.nasa.gov to science.nasa.gov/apod

Nā ʻUhane Māhoe Huki Pū i ke Ola

04/09/2026

Explicação: Nā ʻUhane Māhoe Huki Pū i ke Ola, is the Hawaiian name given to this image of a pair of spiral galaxies locked in a mutual gravitational embrace. Some 200 million light-years distant toward the high flying constellation Pegasus their spectacular, galactic scale merger is captured in sharp detail in the image from the 8.1 meter Gemini North telescope on Maunakea, Hawai‘i. The galaxy pair, known as NGC 7253 and Arp 278, was chosen as a target, researched, and given a Hawaiian name by high school students in the joint Gemini Observatory and University of Hawaiʻi Project Hōkūlani internship program. The name translates to "The Twin Spirits Pulling Together Creating Life". That's both culturally and astronomically appropriate for galaxy collisions that trigger a cosmic maelstrom of star formation from galactic reservoirs of elemental building blocks of life. These merging galaxies are found within a region of Pegasus identified as the Hawaiian navigational constellation Ka Lupe o Kawelo. APOD's main NASA site is moving: From apod.nasa.gov to science.nasa.gov/apod

The Eclipse and the Stork

03/09/2026

Explicação: How do animals react to a total solar eclipse? The featured image shows a stork roosting on her nest in Poland at a partial phase of the recent total solar eclipse. If you are lucky enough to experience a total eclipse somewhere quiet and close to nature, you may be able to notice unusual daytime animal behaviors. During totality, you may hear nighttime sounds like crickets and frogs and see fireflies. In the dark, most birds are quiet. Thinking that it is time to go to bed, ducks and other waterfowl prepare to sleep on one leg, with their heads turned around and their beaks tucked into their back feathers (they don't really sleep with their heads tucked under one wing). When sunlight returns at the end of totality, songbirds greet the new "morning" with their dawn songs. The crickets and frogs go quiet again. Animals and people resume their lives, only briefly disturbed by the chance alignment of our Sun and Moon. APOD's main NASA site is moving : From apod.nasa.gov to science.nasa.gov/apod

Créditos: Włodzimierz Bubak Text: Cecilia Chirenti (NASA GSFC, UMCP, CRESST II)