Pic of the Week: Dwarf Starburst Galaxy Henize 2-10

Posted on by onespaceman2000
Image (Credit): Dwarf starburst galaxy Henize 2-10. (NASA, ESA, Zachary Schutte (XGI), Amy Reines (XGI), Alyssa Pagan (STScI))

This week’s photo is from the Hubble Space Telescope. It shows the Dwarf starburst galaxy Henize 2-10, which lies 34 million light years away. NASA notes that “The bright region at the center, surrounded by pink clouds and dark dust lanes, indicates the location of the galaxy’s massive black hole and active stellar nurseries.”

The image below better illustrates the link between the massive black hole and the related star formation. NASA explains:

A pullout of the central region of dwarf starburst galaxy Henize 2-10 traces an outflow, or bridge of hot gas 230 light-years long, connecting the galaxy’s massive black hole and a star-forming region. Hubble data on the velocity of the outflow from the black hole, as well as the age of the young stars, indicates a causal relationship between the two. A few million years ago, the outflow of hot gas slammed into the dense cloud of a stellar nursery and spread out, like water from a hose impacting a mound of dirt. Now clusters of young stars are aligned perpendicular to the outflow, revealing the path of its spread.

Image (Credit): Dwarf starburst galaxy Henize 2-10 with a pullout showing the black hole and related star formation. (NASA, ESA, Zachary Schutte (XGI), Amy Reines (XGI), Alyssa Pagan (STScI))

Pic of the Week: Dazzling Star Cluster

Posted on by onespaceman2000
Image (Credit): Globular cluster Liller 1 (ESA/Hubble & NASA, F. Ferraro)

The image this week is from the NASA/ESA Hubble Space Telescope. It shows a cluster of old and young stars in the globular cluster Liller 1 located within the bulge of the Milky Way Galaxy. Here is a full explanation from NASA:

The muted red tones of the globular cluster Liller 1 are partially obscured in this image by a dense scattering of piercingly blue stars. In fact, it is thanks to Hubble’s Wide Field Camera 3 (WFC3) that we are able to see Liller 1 so clearly in this image, because the WFC3 is sensitive to wavelengths of light that the human eye cannot detect. Liller 1 is only 30 000 light-years from Earth — relatively neighbourly in astronomical terms — but it lies within the Milky Way’s ‘bulge’, the dense and dusty region at our galaxy’s centre. Because of that, Liller 1 is heavily obscured from view by interstellar dust, which scatters visible light (particularly blue light) very effectively. Fortunately, some infrared and red visible light are able to pass through these dusty regions. WFC3 is sensitive to both visible and near-infrared (infrared that is close to the visible) wavelengths, allowing us to see through the obscuring clouds of dust, and providing this spectacular view of Liller 1. 

Liller 1 is a particularly interesting globular cluster, because unlike most of its kind, it contains a mix of very young and very old stars. Globular clusters typically house only old stars, some nearly as old as the Universe itself. Liller1 instead contains at least two distinct stellar populations with remarkably different ages: the oldest one is 12 billion years old and the youngest component is just 1-2 billion years old. This led astronomers to conclude that this stellar system was able to form stars over an extraordinary long period of time. 

JWST: It Can Be Dangerous in Space

Posted on by onespaceman2000
Image (Credit): Artist’s image of the James Webb Space Telescope. (NASA)

NASA reports that the James Webb Space Telescope (JWST) was hit by a micrometeroid last month. The tweet from NASAWebb stated:

In late May, Webb sustained a dust-sized micrometeroid impact to a primary mirror segment. Not to worry: Webb is still performing at a level that exceeds all mission requirements.

A second story explained how NASA tested the JWST for just such instances, though the final sentence was a little more worrisome:

Webb’s mirror was engineered to withstand bombardment from the micrometeoroid environment at its orbit around Sun-Earth L2 of dust-sized particles flying at extreme velocities. While the telescope was being built, engineers used a mixture of simulations and actual test impacts on mirror samples to get a clearer idea of how to fortify the observatory for operation in orbit. This most recent impact was larger than was modeled, and beyond what the team could have tested on the ground.

And this sentence is also worrisome:

Since launch, we have had four smaller measurable micrometeoroid strikes that were consistent with expectations and this one more recently that is larger than our degradation predictions assumed. 

The $10 billion space telescope, which is still working to become operational, is not expected to share images until mid-July. Unlike the Hubble Space Telescope, NASA cannot send astronauts out to the JWST to make periodic repairs. The JWST currently sits in the L2 Lagrange point about 1 million miles away. All NASA can do now is try to compensate for the damage as best it can.

Hubble: Galaxies Are Moving Away Even Faster Than Expected

Posted on by onespaceman2000
Credit: Hubblesite.org.

Astronomers using data from the Hubble Space Telescope have determined that the universe is expanding at a faster rate than estimated earlier. Using the Hubble data, the press release stated:

After 30 years of meticulous work using the Hubble telescope’s extraordinary observing power, numerous teams of astronomers have narrowed the expansion rate to a precision of just over 1%. This can be used to predict that the universe will double in size in 10 billion years.

I like another line in the Hubble press release following the discussion of another discovery showing that “the present expansion rate is different than it is expected to be as the universe appeared shortly after the big bang.” The press release noted:

You think this would frustrate astronomers, but instead it opens the door to discovering new physics, and confronting unanticipated questions about the underlying workings of the universe. And, finally, reminding us that we have a lot more to learn among the stars.

That’s the spirit. And yes, that galaxy far, far away is just getting ever further away every day.

Hubble and the Unexpected Asteroids

Posted on by onespaceman2000
Image (Credit): This Hubble image is a mosaic of many exposures where some asteroids appear multiple times. (NASA, ESA, and B. Sunnquist and J. Mack/STScI)

The Hubble Space Telescope’s old data still holds some secrets. The European Space Agency (ESA) has reported that astronomers have found 1,031 unidentified asteroid trails in earlier data from the NASA/ESA Hubble Space Telescope. The asteroids were located by the Hubble Asteroid Hunter project, which defines the project in this way:

…we use archival images made by the Hubble Space Telescope to find asteroids observed by chance. The ESASky team compared the observation epoch and field of view of these images with the computed orbits of asteroids, to identify possible observations. The positions predicted by the algorithm, nevertheless, have some associated uncertainty because the ephemerides are not always known to great precision. This uncertainty increases with the amount of time between the last observation date and the date we predict the position for. Identifying the asteroids in the images (if present) and marking the exact position of their trail allows us to update the ephemerides and help us better characterise these objects.

More than 11,000 volunteers studied about 37,000 composite images taken by the Hubble between April 2002 and March 2021. The volunteers found about 1,000 asteroid trails, which when combined with other images spotted using artificial intelligence added to 1,701 asteroid trails. Of these, 1,031 are unidentified trails most likely associated with smaller asteroids. The analysis of these unidentified trails will continue.

This is a great example of the public assisting with astronomy and allowing for more timely results. It’s a helpful model for future astronomy endeavors.