Image (Credit): The Dorado group in the southern hemisphere. (ESA/Euclid/Euclid Consortium/NASA)
This week’s image was captured by the European Space Agency’s (ESA) Euclid space telescope. Launched last summer to create a 3D map of the universe, it has been pretty busy sending back some impressive images. This particular image shows the Dorado group of galaxies, one of the richest group of galaxies in the southern hemisphere. The grouping of approximately 70 galaxies is about 62 million light-years away.
Image (Credit): Hubble image of a triple-star system. (NASA, ESA, G. Duchene (Universite de Grenoble I); Image Processing: Gladys Kober (NASA/Catholic University of America))
This week’s image is from the NASA/ESA Hubble Space Telescope. It shows a triple-star system that consists of the variable star HP Tau, HP Tau G2, and HP Tau G3.
HP Tau is known as a T Tauri star, a type of young variable star that hasn’t begun nuclear fusion yet but is beginning to evolve into a hydrogen-fueled star similar to our Sun. T Tauri stars tend to be younger than 10 million years old ― in comparison, our Sun is around 4.6 billion years old ― and are often found still swaddled in the clouds of dust and gas from which they formed.
Image (Credit): Jupiter with the small moon Amalthea appearing in its Great Red Spot. (Image data: NASA/JPL-Caltech/SwRI/MSSS. Image processing by Gerald Eichstädt)
This week’s image comes from NASA’s Juno mission during a flyby back in March. It shows Jupiter’s smallest moon Amalthea orbiting Jupiter with the Great Red Spot in the background. The potato-shaped moon has a radius of 52 miles and completes an orbit of the giant planet in about half an Earth day.
You can read more about the photograph at this NASA site.
Image (Credit): Close-up of Jupiter with the small moon Amalthea appearing in its Great Red Spot. (Image data: NASA/JPL-Caltech/SwRI/MSSS. Image processing by Gerald Eichstädt)
Image (Credit): The Little Dumbell Nebula as captured by the Hubble Space Telescope. (NASA, ESA, STScI)
This week’s image comes from the NASA/European Space Agency’s Hubble Space Telescope. It shows what is called the Little Dumbbell Nebula, more formally called Messier 76, M76, or NGC 650/651, which is about 3,400 light-years away. The image is being shared as part of the celebration of Hubble’s 34th anniversary, which is discussed in this video.
M76 is classified as a planetary nebula, an expanding shell of glowing gases that were ejected from a dying red giant star. The star eventually collapses to an ultra-dense and hot white dwarf. A planetary nebula is unrelated to planets, but have that name because astronomers in the 1700s using low-power telescopes thought this type of object resembled a planet.
M76 is composed of a ring, seen edge-on as the central bar structure, and two lobes on either opening of the ring. Before the star burned out, it ejected the ring of gas and dust. The ring was probably sculpted by the effects of the star that once had a binary companion star. This sloughed off material created a thick disk of dust and gas along the plane of the companion’s orbit. The hypothetical companion star isn’t seen in the Hubble image, and so it could have been later swallowed by the central star. The disk would be forensic evidence for that stellar cannibalism.
The primary star is collapsing to form a white dwarf. It is one of the hottest stellar remnants known at a scorching 250,000 degrees Fahrenheit, 24 times our Sun’s surface temperature. The sizzling white dwarf can be seen as a pinpoint in the center of the nebula. A star visible in projection beneath it is not part of the nebula.
Pinched off by the disk, two lobes of hot gas are escaping from the top and bottom of the “belt,” along the star’s rotation axis that is perpendicular to the disk. They are being propelled by the hurricane-like outflow of material from the dying star, tearing across space at two million miles per hour. That’s fast enough to travel from Earth to the Moon in a little over seven minutes! This torrential “stellar wind” is plowing into cooler, slower-moving gas that was ejected at an earlier stage in the star’s life, when it was a red giant. Ferocious ultraviolet radiation from the super-hot star is causing the gases to glow. The red color is from nitrogen, and blue is from oxygen.
Given our solar system is 4.6 billion years old, the entire nebula is a flash in the pan by cosmological timekeeping. It will vanish in about 15,000 years.
Image (Credit): The Horsehead Nebula captured by the JWST. (NASA, ESA, CSA, Karl Misselt (University of Arizona), Alain Abergel (IAS, CNRS))
This week’s image comes from the James Webb Space Telescope (JWST). It shows a close-up of the well known Horsehead Nebula, which is about 1,375 light years from Earth. The clarity of the many galaxies in the distance makes this an even more amazing image.
This image of the Horsehead Nebula from NASA’s James Webb Space Telescope focuses on a portion of the horse’s “mane” that is about 0.8 light-years in width. It was taken with Webb’s NIRCam (Near-infrared Camera). The ethereal clouds that appear blue at the bottom of the image are filled with a variety of materials including hydrogen, methane, and water ice. Red-colored wisps extending above the main nebula represent both atomic and molecular hydrogen. In this area, known as a photodissociation region, ultraviolet light from nearby young, massive stars creates a mostly neutral, warm area of gas and dust between the fully ionized gas above and the nebula below. As with many Webb images, distant galaxies are sprinkled in the background.