Local Black Hole: False Alarm

Posted on by onespaceman2000
Source/Credit: MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile.

You may have remembered this NASA tweet from September 2020:

HR 6819 is the closest black hole we’ve detected so far, and it lies about 1,000 light-years away. ⚫️ Statistics say there should be one as close as 65 light-years, though we may never detect it unless it lights up!

The original European Space Agency (ESA) press release noted that an invisible object has two companion stars, one of which orbits the unseen object every 40 days. The data for this finding used the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile.

Well, you can relax. The ESA announced last week that HR 6819 is not a black hole based on new data from ESO’s Very Large Telescope (VLT) and Very Large Telescope Interferometer (VLTI):

Our best interpretation so far is that we caught this binary system in a moment shortly after one of the stars had sucked the atmosphere off its companion star. This is a common phenomenon in close binary systems, sometimes referred to as “stellar vampirism” in the press,” explains Bodensteiner, now a fellow at ESO in Germany and an author on the new study. “While the donor star was stripped of some of its material, the recipient star began to spin more rapidly.

So, mystery solved. Now we need to talk about local vampires!

Another Russian Casualty: Mars

Posted on by onespaceman2000
Source/Credit: The Exomars rover from the ESA.

Yesterday, the European Space Agency (ESA) announced that another space program has been impacted by the Russia’s invasion of Ukraine:

Regarding the ExoMars programme continuation, the sanctions and the wider context make a launch in 2022 very unlikely. ESA’s Director General will analyse all the options and prepare a formal decision on the way forward by ESA Member States.

The ESA website on the Exomars program notes that it is a two part mission searching for life on Mars: the Trace Gas Orbiter launched in 2016 and the Exomars rover and surface platform planned for launch in 2022. NASA also contributed to this latest mission:

NASA’s participation in the 2022 ExoMars Rover mission includes providing critical elements to the premier astrobiology instrument on the rover, the Mars Organic Molecule Analyzer (MOMA). By studying organic molecules, the chemical building blocks of life, MOMA is designed to help answer questions about whether life ever existed on Mars, along with its potential origin, evolution and distribution on the Red Planet.

The list of impacted space missions will only grow.

Russia Interrupts Space Missions

Posted on by onespaceman2000
Source/Credit: Guiana Space Center launch pads from the ESA.

Be prepared. With the ongoing Russian invasion of Ukraine and the related U.S. and European sanctions, we can expect some delays and cancellations in upcoming space missions. The latest news story is Russia’s pull out of the Guiana Space Center in Kourou, French Guiana, leading to the delayed launch of two European Space Agency (ESA) Galileo navigation satellites that were to be sent into orbit on Soyuz rockets.

Director General of Russia’s Roscosmos tweeted:

In response to EU sanctions against our enterprises, Roscosmos is suspending cooperation with European partners in organizing space launches from the Kourou cosmodrome and withdrawing its technical personnel, including the consolidated launch crew, from French Guiana.

Luckily, the world is becoming less and less reliant on Russian rockets. Nonetheless, it would be better for Russia to focus on scientific missions again rather than military missions. Rockets should be aimed at the stars instead of the Ukrainian people.

Remnants of Another Galaxy Found in the Milky Way

Posted on by onespaceman2000
Source/Credit: Gaia spacecraft map of the Milky Way from ESA.

The European Space Agency (ESA) reported scientists found the remnants of another galaxy that collides with our galaxy 8-10 billion years ago. This would be the sixth such grouping or galaxy to be found within the Milky Way. We commonly hear about merging planets in the early stages of our solar system, but that is small stuff by comparison. Observations from ESA’s Gaia spacecraft led to this discovery. This merged galaxy is called “Pontus,” the name of one of the first children of Gaia, the Greek goddess of the Earth.

An earlier ESA release discussed the number of galaxies that arrived more recently and may pass us by or be caught by the Milky Way and pulled apart like Pontus and the others:

François Hammer, Observatoire de Paris – Université Paris Sciences et Lettres, France, and colleagues from across Europe and China, used the Gaia data to calculate the movements of 40 dwarf galaxies around the Milky Way. They did this by computing a set of quantities known as the three-dimensional velocities for each galaxy, and then using those to calculate the galaxy’s orbital energy and the angular (rotational) momentum.

They found that these galaxies are moving much faster than the giant stars and star clusters that are known to be orbiting the Milky Way. So fast, that they couldn’t be in orbit yet around the Milky Way, where interactions with our galaxy and its contents would have sapped their orbital energy and angular momentum…

So will these newcomers settle into orbit or simply pass us by? “Some of them will be captured by the Milky Way and will become satellites,” says François.

I wonder what is would be like sitting in one of those smaller galaxies awaiting your fate. Of course, it will be a very long wait.

Source/Credit: Dwarf galaxies around the Milky Way from ESA.
Source/credit: Gaia spacecraft from the ESA/- C. Carreau.
Posted in ESA

Pic of the Week: Giant Star on the Edge of Destruction

Posted on by onespaceman2000
Source/Credit: NASA/ESA Hubble Space Telescope

This week’s image from the Hubble Space Telescope shows an erupting star, as explained by the European Space Agency’s (ESA) Hubble site:

The giant star…is waging a tug-of-war between gravity and radiation to avoid self-destruction. The star, called AG Carinae, is surrounded by an expanding shell of gas and dust — a nebula — that is shaped by the powerful winds of the star. The nebula is about five light-years wide, which equals the distance from here to our nearest star, Alpha Centauri.

The huge structure was created from one or more giant eruptions several thousand years ago. The star’s outer layers were blown into space, the expelled material amounting to roughly 10 times the mass of our Sun. These outbursts are typical in the life of a rare breed of star called a Luminous Blue Variable (LBV), a brief unstable phase in the short life of an ultra-bright, glamorous star that lives fast and dies young. These stars are among the most massive and brightest stars known. They live for only a few million years, compared to the roughly 10-billion-year lifetime of our own Sun. AG Carinae is a few million years old and resides 20,000 light-years away inside our Milky Way galaxy. The star’s expected lifetime is between 5 million and 6 million years.