Young Stars Blast a Hole in Space


There is a black patch of space in NGC 1999, and for years astronomers have thought it was just a dense cloud of gas and dust, blocking light from passing through. But the Herschel infrared space telescope – which has the ability to peer into these dense clouds — has made an unexpected discovery. This black patch is actually a hole that has been blown in the side of the nebula by the jets and winds of gas from the young stellar objects in this region of space. “No-one has ever seen a hole like this,” said Tom Megeath, of the University of Toledo in the USA. “It’s as surprising as knowing you have worms tunneling under your lawn, but finding one morning that they have created a huge, yawning pit.”

Any previous descriptions of NCG 1999 said that the ominous dark cloud in the center was actually a condensation of cold molecular gas and dust so thick and dense that it blocks light. And astronomers had no reason to believe otherwise, until Herschel’s powerful infrared eyes took a look from space.

A Hubble image of NCG 1999 showing the dark patch. Credit: Hubble Heritage Team (STScI) and NASA

When Herschel looked in the direction of this nebula to study nearby young stars, the cloud continued to look black. But, that should not be the case. Herschel’s infrared eyes are designed to see into such clouds. Either the cloud was immensely dense or something was wrong.

Investigating further using ground-based telescopes, astronomers found the same story however they looked: this patch looks black not because it is a dense pocket of gas but because it is truly empty. Something has blown a hole right through the cloud.

Stars are born in dense clouds of dust and gas. Although jets and winds of gas have been seen coming from young stars in the past, it has always been a mystery exactly how a star uses these to blow away its surroundings and emerge from its birth cloud. With Herschel, this may be the first time we can see this process.

The astronomers think that the hole must have been opened when the narrow jets of gas from some of the young stars in the region punctured the sheet of dust and gas that forms NGC 1999. The powerful radiation from a nearby mature star may also have helped to clear the hole. Whatever the precise chain of events, it could be an important glimpse into the way newborn stars disperse their birth clouds.

Source: ESA

Herschel Spots Previously Unseen Stars in Rosette Nebula

Infrared image of the Rosette molecular cloud by the Herschel space observatory. Credits: ESA/PACS & SPIRE Consortium/HOBYS Key Programme Consortia

Wow, what a gorgeous new image from the Herschel telescope – and what makes this especially stunning is that we’ve never seen these stars before! And these stars in the Rosette Nebula are huge, as each one is up to ten times the mass of our Sun. “High-mass star-forming regions are rare and further away than low-mass ones,” said Frédérique Motte, from the Laboratoire AIM Paris-Saclay, France. “So astronomers have had to wait for a space telescope like Herschel to reveal them.”
Continue reading “Herschel Spots Previously Unseen Stars in Rosette Nebula”

New VISTA of Orion


Oh-oh-oh Orion! The new VISTA (Visible and Infrared Survey Telescope for Astronomy) infrared survey telescope has used its huge field of view to show the full splendor of the Orion Nebula. With its infrared eyes, it has peered deeply into dusty regions that are normally hidden to expose the curious behavior of the very active young stars buried there.

VISTA is the latest addition to ESO’s Paranal Observatory. It is the largest survey telescope in the world and is dedicated to mapping the sky at infrared wavelengths. The large (4.1-metre) mirror, wide field of view and very sensitive detectors make VISTA a unique instrument. This dramatic new image of the Orion Nebula illustrates VISTA’s remarkable powers.

The Orion Nebula is about 1,350 light-years from Earth. Although spectacular when seen through an ordinary telescope, what can be seen using visible light is only a small part of a cloud of gas in which stars are forming. Most of the action is deeply embedded in dust clouds and to see what is really happening astronomers need to use telescopes with detectors sensitive to the longer wavelength radiation that can penetrate the dust. VISTA has imaged the Orion Nebula at wavelengths about twice as long as can be detected by the human eye.

Four highlights of the new VISTA image of Orion. Credit: ESO

On the upper-left, the central region of VISTA’s view of the Orion Nebula is shown, centered on the four dazzling stars of the Trapezium. A rich cluster of young stars can be seen here that is invisible in normal, visible light images. In the lower-right panel the part of the nebula to the north of the center is shown. Here there are many young stars embedded in the dust clouds that are only apparent because their infrared glow can penetrate the dust and be detected by the VISTA camera. Many outflows, jets and other interactions from young stars are apparent, seen in the infrared glow from molecular hydrogen and showing up as red blobs. On the upper-right, a region to the west of center is shown. Here the fierce ultraviolet light from the Trapezium is sculpting the gas clouds into curious wavy shapes. A distant edge-on spiral galaxy is also seen shining right through the nebula. At the lower-left a region south of the center is shown. Each extract covers a region of sky about nine arcminutes across.

All these features are of great interest to astronomers studying the birth and youth of stars.

Source: ESO

Pretty Picture of the Week: NGC 3603

This magnificent image of the giant stellar nursery surrounding NGC 3603 was taken by the Very Large Telescope at Cerro Paranal, Chile. This nebula is a starburst region, a huge star-making factory where stars form frantically from the nebula’s billowing clouds of gas and dust. It is located 22,000 light-years away from the Sun, and is the closest region of this kind known in our galaxy. Thousands of stars inhabit this region, with most having masses similar to that of our sun. But other stars are some of the most spectacular and massive stars around. In fact, one star, NGC 3603 A1, is the most massive star ever “weighed.” Several blue supergiant stars crowd into a volume of less than a cubic light-year, along with three so-called Wolf-Rayet stars — extremely bright and massive stars that will do the supernova gig relatively soon. The Bad Astronomer tells it way better than I, so go check out his gigantisized blog post.

Source: ESO

Stunning New Look at the Cat’s Paw Nebula


This striking new image shows the vast cloud of gas and dust known as the Cat’s Paw Nebula or NGC 6334. This glowing nebula resembles a gigantic pawprint of a celestial cat out on an errand across the Universe. This complex region of gas and dust, where numerous massive stars are born, lies near the heart of the Milky Way galaxy, about 5500 light-years away. It covers an area on the sky slightly larger than the full Moon. The whole gas cloud is about 50 light-years across.

This new portrait of the Cat’s Paw was created from images taken with the Wide Field Imager instrument at the 2.2-metre MPG/ESO telescope at the La Silla Observatory in Chile, combining images taken through blue, green and red filters, as well as a special filter designed to let through the light of glowing hydrogen.

The nebula appears red because its blue and green light are scattered and absorbed more efficiently by material between the nebula and Earth. The red light comes predominantly from hydrogen gas glowing under the intense glare of hot young stars.

Particularly striking is the red, intricate bubble in the lower right part of the image. This is most likely either a star expelling large amount of matter at high speed as it nears the end of its life or the remnant of a star that already has exploded.

NGC 6334 is one of the most active nurseries of massive stars in our galaxy and has been extensively studied by astronomers. The nebula conceals freshly minted brilliant blue stars — each nearly ten times the mass of our Sun and born in the last few million years. The region is also home to many baby stars that are buried deep in the dust, making them difficult to study. In total, the Cat’s Paw Nebula could contain several tens of thousands of stars.

Click here to see videos that pan and zoom into this stunning new image.

Nebula Wallpaper

Nebula Wallpaper

Want a nebula wallpaper to put as the background image of your computer desktop? Here’s a handful of nebula images. To make any of them your computer’s background image, just click on the image to see a larger version. Then right-click on the image and choose to set the image as your desktop background.

The nebula wallpaper is the Flame Nebula, captured by the European Southern Observatory. Also known as NGC 2024, it’s a famous nebula located about 1,500 light-years away in the constellation of Orion. The bright star at the top of the image is Alnitak, one of the belt stars of Orion.

Crab Nebula

This is a wallpaper image of the Crab Nebula taken by the Hubble Space Telescope. Also known as M1, the Crab Nebula is the results of a supernova explosion that occurred almost 1000 years ago. Astronomers in 1054 AD reported a star brighting in the sky, and lasting for a few weeks before it dimmed again. That was the supernova that went on to create the Crab Nebula.

Butterfly Nebula

This is a wallpaper of the Butterfly Nebula (or NGC 6302) captured by Hubble. This is a planetary nebula, the result of a dying star blasting out its outer layers into space. This is what our own Sun might do in about 7 billion years from now after it becomes a red giant star.

Ring Nebula

This is Hubble Space Telescope image of the Ring Nebula, also known as M57. It’s actually a planetary nebula, where the outer layers of a dying star are puffed out into space. The Ring Nebula is located about 4000 light-years away, and measures about 500 times larger than the Solar System.

Carina Nebula

This is the Carina Nebula, photographed by the Hubble Space Telescope. This is just one pillar of gas and dust in the nebula, measuring 2 light-years across. It’s located about 7,500 light years from Earth.

We’ve written many articles about nebulae for Universe Today. Here’s an article about dust in the Iris Nebula, and here’s an article about Hubble images of the Helix Nebula.

If you’d like more information on nebulae, check out NASA’s Photo Gallery of Nebulae, and here’s a link to the Hubblesite Homepage for recent stories and images.

We’ve recorded an episode of Astronomy Cast all about nebulae. Listen here, Episode 111: Nebulae.

Pillars of Creation

The pillars of creation are a part of the emission nebula, or H II region, M16 (also called the Eagle Nebula).

The iconic Hubble Space Telescope image shown here was taken on April Fool’s Day, 1995, using the WFPC2 camera (you can tell it’s that camera from the W-shaped bite taken out of it). It was snapped as part of a research program by Arizona State University’s Jeff Hester and Paul Scowen, and released to the general public on 2 November (i.e. after the proprietary six-month period was over). Embryonic Stars Emerge from Interstellar “Eggs” – that’s the title of the HubbleSite Press Release; “eggs” is a play on EGGs, Evaporating Gas Globules, “dense, compact pockets of interstellar gas“. Interestingly, the name “pillars of creation” is found only in the image title, and nowhere in the Press Release text!

The pillars of creation – and M16 – are about 7,000 light-years away, and each are several light-years long (of course, there’s no “up” in space, so if you turn the image upside down, you see downward hanging linear features … but ‘stalactites of creation’ just isn’t at all catchy).

This region of M16 has been imaged in the x-ray region of the electromagnetic spectrum, by Chandra, in the infrared by Spitzer, and in infrared hi-def from the ground by the ESO’s VLT ANTU telescope.

Hubble has imaged many similar star-forming regions, complete with their own pillars; for example NGC 602 (in the Small Magellanic Cloud; zooming in on this image is fun – can you spot some of the ‘stalactites of creation’?), NGC 6357 (in our own Milky Way, just a tad further away than M16), and a different pillar (“Stellar Spire”) in the Eagle Nebula. Who knows? Maybe, one day, the Horsehead Nebula may become a pillar of creation too!

Universe Today has many articles on these pillars, Shadows Helped Form the “Pillars of Creation”, The Eagle … Has Arrived, Chandra Gives Another Look at the Pillars of Creation, Spitzer’s Version of the Pillars of Creation, and Eagle Nebula’s Pillars Were Wiped Out Thousands of Years Ago.

The Pillars of Creation also feature in Astronomy Cast episodes Nebulae, Stellar Populations, and Stellar Nurseries.

The Eye of God

There was an email going around a few years ago talking about “the Eye of God”. This photo was actually an image of the Helix Nebula taken by the Hubble Space Telescope.

The Eye of God nebula is a bright planetary nebula located about 700 light-years away in the constellation Aquarius; it’s also known as NGC 7293. In fact, the Helix Nebula is probably the closest planetary nebula we can see in the sky, and it shows the future that stars like our Sun go through when they run out of fuel and puff out their outer layers.

It’s thought that the Helix Nebula is actually cylindrical shaped. From our perspective, we’re looking down the cylinder to see the central star. Astronomers estimate that the Helix Nebula is about 10,600 years old, based on the rate of expansion of the nebula.

With the power of the Hubble Space Telescope, astronomers were able to see knots of material in the nebula. They’ve now discovered more than 20,000 of these cometary knots in the nebula. These knots have cometary tails, and it’s been discovered that they can collide with one another.

Here’s the email you might get:

Subject: Fw: Eye of God
This is a picture taken by NASA with the Hubble telescope. They are referring to it as the “Eye of God”. I thought it was beautiful and worth sharing.

Some emails even say that this is a rare event that only happens once every 3,000 years. The reality is that this is just a beautiful photograph taken by the Hubble Space Telescope. There are other images that have been taken by other telescopes and they look beautiful as well.

We’ve written several articles about the Helix Nebula for Universe Today. Here’s an article about a new view into the Helix Nebula, and here’s an article about comets colliding inside the Helix Nebula.

If you’d like more info on the Helix Nebula, here’s a nice picture from the La Silla Observatory at Astronomy Picture of the Day.

We’ve also recorded an entire episode of Astronomy Cast just about nebulae. Listen here, Episode 111: Nebulae.

Hubble Sees Dazzling Dust in the Iris Nebula


Another gorgeous image from Hubble! This close-up of NGC 7023, or the Iris Nebula, shows an area filled with cosmic dust. Illuminated from above by the nearby star HD 200775, the dust resembles pink cotton candy, accentuated with diamond-like stars. The “cotton candy” is actually made up of tiny particles of solid matter, with sizes from ten to a hundred times smaller than those of the dust grains we find on Earth, and the “diamonds” are both background and foreground stars.

The image was taken previous to Hubble’s recent servicing mission, using the Advanced Camera for Surveys. Astronomers also used Hubble’s Near Infrared Camera and Multi-Object Spectrometer (NICMOS) instrument to try to determine which chemical elements are present in the nebula.

NGC 7023 is a reflection nebula, which means it scatters light from the massive nearby star. Reflection nebulae are different from emission nebulae, which are clouds of gas that are hot enough to emit light themselves. Reflection nebulae tend to appear blue because of the way light scatters, but parts of the Iris Nebula appear unusually red-ish or pink.

See more, including a movie pan of the nebula here.

Helix Nebula

The Helix Nebula is one of the most familiar nebulae in astronomy, and it’s been nicknamed the “Eye of God”. Its official designation is NGC 7293, the Helix Nebula is located inside the constellation of Aquarius. The Helix Nebula is one of the closest examples of a planetary nebula. Astronomers have estimated its distance to only be 700 light-years away.

The central star of the Helix Nebula was once a star very similar to our own Sun. As the star neared the end of its life, it expanded into a red giant and puffed away its outer layers. The central star is destined to become a white dwarf star, as it slowly cools down. It’s no longer actively fusing hydrogen, and only shines with the remaining heat from when it was once a star.

The Helix Nebula that we see today is actually just a momentary phase in the death of the star. The inner layers of gas and dust expanding away from the central star were probably released about 6,500 years ago, with the outer layer released about 12,000 years ago. We can see them because they’re illuminated by the central star. But eventually they’ll get far enough away that they’re no longer bright enough to see. From that point on we’ll just see the central white dwarf star.

Because the Helix Nebula is so close, images from the Hubble Space Telescope revealed knots of material in the expanding shells of gas and dust. There are more than 20,000 of these knots in the nebula, and they have cometlike tails stretching away from the central star.

We’ve written many articles about the Eye of God nebula for Universe Today. Here’s an article about a new view into the Helix Nebula, and here’s an article about comets colliding inside the Helix Nebula.

Here’s a nice photograph of the Helix Nebula taken by the Hubble Space Telescope.

We’ve also recorded an episode of Astronomy Cast all about nebulae. Listen here, Episode 111: Nebulae.