Astronomy Ideas on Borrowed Time?

Posted on by onespaceman2000
Image (Credit): The position of our Sun as it orbits the Milky Way’s center. (Stefan Payne-Wardenaar)

A recent Big Think story, “5 Consensus Ideas in Astronomy That Might Soon be Overturned,” comes as a good time as we reach further into space and back into time using the James Webb Space Telescope (JWST) and contemplate other telescopes that should come online shortly.

The story highlights these five ideas:

  • Dark energy is a cosmological constant;
  • Stars predate black holes;
  • Jovian planets protect terrestrial ones;
  • Most of the galaxy is uninhabitable; and
  • Globular clusters are planet-free.

For instance, regarding the uninhabitable areas of the galaxy, the Big Think story states:

Among its many discoveries, the ESA’s Gaia mission has found that the Milky Way galaxy not only has a warp to its galactic disk, but that the warp in the disk precesses and wobbles, completing a full rotation for roughly every three revolutions of the Sun [shown in yellow above] around the galactic center. Most astronomers assume that regions with too many stellar cataclysms in them, like the centers of galaxies, may be completely uninhabitable. But this picture is far from certain.

It is worth reading through the list and keeping these ideas in mind, and then following the JWST stories as they unfold. I bet you will be able to make a much longer list as old consensus ideas come apart and new ideas quickly follow.

More on Black Holes

Posted on by onespaceman2000
Image (Credit): Image from the Very Large Telescope in Chile showing stars orbiting the supermassive black hole that lies at the heart of the Milky Way. (ESO/MPE)

The earlier article on a black hole binary system was pretty amazing, yet the video accompanying the story was created to demonstrate the phenomena. I found an even more amazing real video of stars orbiting the supermassive black hole at the center or the Milky Way galaxy. You can see the 20-year time-lapse video here from the NaCo instrument on the European Space Telescope’s Very Large Telescope in Chile. This black hole, Sagittarius A*, is about 27 000 light-years away from Earth.

Space Stories: Black Holes, X-Rays, and Exploding Stars

Posted on by onespaceman2000
Image (Credit): Animation showing a binary system of a large, hot blue star and a black hole orbiting each other. (ESO/L.Calçada)

Here are some recent stories of interest.

—SciTechDaily.com: “Astronomers Have Discovered an Especially Sneaky Black Hole“

VFTS 243 is a binary system, which means it is composed of two objects that orbit a common center of mass. The first object is a very hot, blue star with 25 times the mass of the Sun, and the second is a black hole nine times more massive than the Sun. VFTS 243 is located in the Tarantula Nebula within the Large Magellanic Cloud, a satellite galaxy of the Milky Way located about 163,000 light-years from Earth.

—SpaceNews.com: “ESA Scaling Back Design of X-ray Astronomy Mission“

Faced within increasing costs, the European Space Agency is looking for ways to revise the design of a large X-ray space telescope, an effort that could have implications for NASA’s own astrophysics programs…That effort will involve potential changes to its instrument configuration as well as creation of a science “redefinition” team to reconsider science objectives. The goal will be to develop a revised concept, called a minimum disrupted mission, that will cost ESA no more than 1.3 billion euros but still perform science expected of a flagship-class mission.

—NASA.gov: “NASA Rocket Mission Using ‘Astronomical Forensics’ to Study Exploded Star“

A NASA-funded sounding rocket mission will observe the remnants of an exploded star, uncovering new details about the eruption event while testing X-ray detector technologies for future missions. The High-Resolution Microcalorimeter X-ray Imaging, or Micro-X, experiment will launch Aug. 21 from the White Sands Missile Range in New Mexico. The mission’s target of study is some 11,000 light-years away from Earth, off the edge of the W-shaped constellation known as Cassiopeia. There, a massive bubble of radiant material known as Cassiopeia A, or Cas A for short, marks the site of a brilliant stellar death.

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))

Black Holes in the Center of Galaxies are More Common Than We Thought

Posted on by onespaceman2000
Image (Credit): An artist’s drawing a stellar black hole named Cygnus X-1. (NASA/CXC/M.Weiss)

We already knew a supermassive black hole sits at the center of our galaxy and others like it, but what about dwarf galaxies? SciTechDaily reports that astronomers in the University of North Carolina-Chapel Hill’s Department of Physics & Astronomy have found that large black holes are also more common than previously thought in dwarf galaxies.

The astronomers developed a new way to identify such black holes and found that about 80 percent of all black holes found in dwarf galaxies could be found in this way. These smaller black holes may help to create the supermassive black holes we see in larger galaxies as the dwarf galaxies collide and combine to make the larger galaxies.

Professor Sheila Kannappan, Polimera’s Ph.D. advisor in the Department of Physics & Astronomy and coauthor of the study, stated:

We’re still pinching ourselves…We’re excited to pursue a zillion follow-up ideas. The black holes we’ve found are the basic building blocks of supermassive black holes like the one in our own Milky Way. There’s so much we want to learn about them.

While even Albert Einstein had doubts that his theoretical black hole could exist in reality, astronomers continue to find they are a larger part of the universe than anyone expected. When you consider smaller stellar black holes, the figure is enormous. As NASA noted:

Judging from the number of stars large enough to produce such black holes, however, scientists estimate that there are as many as ten million to a billion such black holes in the Milky Way alone.