What happens when a star dies? In the case of low-mass stars like our Sun and M2-9 pictured above, such stars transform themselves into white dwarfs by throwing off their outer gaseous envelopes. The expelled gas often forms a planetary nebula that fades away over thousand of years. M2-9 is a butterfly planetary nebula 2100 light-years away. There are two stars orbiting inside the central gaseous disk 10 times larger than the orbit of Pluto. The expelled gas of the dying star breaks out from the disk in a bipolar pattern.
NGC 520 is a pair of colliding galaxies a bit over 100 million light-years away. Simulations indicate the pair began interacting about 300 million years ago. The system is still in an early stage of its merger with each galaxy still moving at its own velocity.
This is Messier 96, a spiral galaxy a bit more than 35 million light-years away in the constellation of Leo (The Lion). It is roughly the same mass and size as the Milky Way, but unlike our more or less symmetrical galaxy, M96 is lopsided. Its dust and gas are unevenly spread throughout its weak spiral arms, and its core is not exactly at the apparent galactic center. Its arms are also asymmetrical, perhaps because of the gravitational pull of other galaxies within the same group as Messier 96.
This is the planetary nebula NGC 3918, a brilliant cloud of colorful gas in the constellation of Centaurus, roughly 4,900 light-years from Earth. In the center of the cloud of gas lies a tiny star, the dying remnant of a red giant. When such a star dies, huge clouds of gas are ejected from its surface before collapses to become a white dwarf. Intense ultraviolet radiation from the tiny remnant star causes the surrounding gas cloud to glow.
NGC 3918 has a distinctive eye-like shape with a bright inner shell of gas and a more diffuse outer shell that extends far from the nebula and looks as if it could be the result of two separate irruptions of gas. However, studies of the object suggest that the two cloud components were formed at the same time but are being blown from the star at different speeds. The powerful jets of gas emerging from the ends of the large structure are estimated to be shooting away from the star at speeds of up to 350,000 km/h/
Those squiggly blue lines (most of which are to the right of the frame) are all images of the same galaxy, its light having been gravitationally lensed by the Abell 3827 galaxy cluster. The same galaxy is visible in six different locations in the picture.
That’s the star Hen 2-427 (aka WR 124) at the center of this picture. It’s surrounded by the nebula M1-67. They’re found in the constellation of Sagittarius about 15,000 light-years away. The star shines brightly at the very center of these hot clumps of surrounding gas that it’s ejecting into space at over 150,000 km per hour.
Hen 2-427 is a Wolf–Rayet star. Named after the astronomers Charles Wolf and Georges Rayet, Wolf–Rayet stars are super-hot and characterized by a fierce ejection of mass. In this case, that results in the nebula M1-67 which is estimated to be less than 10,000 years old, a newbie in astronomical terms,
This Hubble image shows the light from a distant quasar being gravitationally lensed by a pair of closer galaxies. The quasar shows up in five places in the image. The four bright spots are obvious. The fifth is a dark spot near the center caused by an interference effect resulting from two galaxies bending the light.
This false color image from infrared data taken by the Herschel Space Observatory shows a stellar nursery about 5,000 light-years away. These dust clouds are associated with the Rosette Nebula in the constellation Monoceros. The bright smudges are cocoons of dust surrounding massive embryonic stars, which will grow up to 10 times the mass of our Sun. The small spots near the center of the image are the embryos of less massive stars.
This visualization shows the new sample of oscillating red giant stars (colored dots) discovered by the Transiting Exoplanet Survey Satellite (TESS). The colors map to each 24-by-96-degree swath of the sky observed during the primary mission. The view then changes to show the positions of these stars within our galaxy, based on distances determined by the Gaia mission. The scale shows distances in kiloparsecs, each equal to 3,260 light-years, and extends nearly 20,000 light-years from the Sun.
Video Credit: Kristin Riebe, Leibniz Institute for Astrophysics Potsdam
Gravitational lensing occurs when light from a distant galaxy is bent by the gravitational pull of an intervening astronomical object. In this image assembled from multiple observations by the Hubble Space Telescope a relatively nearby galaxy cluster (MACSJ0138.0-2155) has lensed the galaxy (MRG-M0138) which is located 10 billion light-years from us.
These images are among the first from Hubble after its return to full science operations. On the left is ARP-MADORE2115-273, a rarely observed example of a pair of interacting galaxies. On the right is ARP-MADORE0002-503, a large spiral galaxy with unusual spiral arms. Most disk galaxies have an even number of spiral arms, but this one has three.
This Hubble image peers deep into the core of the Crab Nebula, revealing its beating heart. At its center are the remnants of a supernova which sends out clock-like pulses of radiation and waves of charged particles. The neutron star at the very center of the Crab Nebula has about the same mass as the Sun, but it’s compressed into an incredibly dense sphere that is only a few miles across. Spinning 30 times a second, the neutron star ticks along, shooting out detectable beams of energy.
This image taken with Hubble’s Wide Field Camera 3 shows a pair of dissimilar galaxies. The one in the upper left is the lenticular galaxy cataloged as 2MASX J03193743+4137580. The spiral galaxy in the lower right has the shorter designation of UGC 2665. They’re both about 350 million light-years away.
UGC 5340 is a nearby dwarf galaxy that is a bit of a puzzlement. It seems to be much younger that the Milky Way and the other galaxies in our local group. We don’t know for sure if that true or, if it is, why.
NGC 1052-DF2 is so diffuse that distant background galaxies can be seen through it. It’s about as wide as the Milky Way, but it contains fewer than 1 % the number of stars. It lacks a central core, spiral arms, or a disk. It also seems to lack any significant amount of dark matter.
Arp 188, aka the Tadpole Galaxy, is a disrupted barred spiral galaxy about 420 million light-years from Earth . Its most noticeable feature is a massive tail of stars about 280,000 light-years long. Astronomers believe that the tail was formed about 100 million years ago by a merger or near merger of two galaxies.
A more compact galaxy crossed in front of a larger one and was partially strung out behind the resulting Tadpole by the gravitational interactions.
This video is a full-globe map of Neptune created from Hubble Space Telescope data taken in January, 2020. The planet completes a rotation every 16 hours.
Neptune has dynamic weather. White clouds of methane ice crystals swirl around the planet, and two giant dark spots, giant storms, circle around the northern hemisphere. Around the southern pole, banding is concentrated where the winds are blowing west to east, in the same direction as the planet’s rotation. but near the equator, the winds blow east to west, in the opposite direction as the planet’s rotation.
The giant vortex near the equator is 4,600 miles across, wider than the Atlantic Ocean. Its slightly smaller companion is 3,900 miles across.