Space and Astronomy News for the 26th of July 2025

Betelgeuse has a companion

Anyone who's spent time looking up at the sky during summer nights downunder would know the large constellation of Orion with its distinctive "saucepan" of comparatively bright stars in the middle. There's a good chance you'd know one of the four "shoulders", bright, reddish star called Betelgeuse. 

Where to find Betelgeuse in the northeastern sky from Sydney around 9.30pm local time on Christmas Day, 2025.

Betelgeuse is a large red supergiant star, probably only around 10 million years old. It's likely to explode as a supernova sometime in the next few or hundred thousand years. (Large, bright stars have short lives. Our own Sun will go through a red giant phase, although not for some billions of years.)

Astronomers have observed brightness changes in Betelgeuse. There could be a number of reasons for this, but a long held theory is that this massive star has a much smaller companion. Finding such a small star has always been tricky given the brightness of Betelgeuse itself. Now scientists lead by NASA’s Ames Research Center have found a clever way to do this and it didn't involve either the James Webb or Hubble Space Telescopes.

Betelgeuse and Siwarha via: NSF NOIRLab

Steve Howell from Ames and his colleagues used a combination of the large Gemini North telescope in Hawai’i, and a clever camera called the Alopeke Speckle Instrument. This camera is able to take multiple short exposures and combines them in such a way to overcome atmospheric disturbances. (Those keen on planetary imaging are probably recognising these sorts of techniques.) 

“I hope our discovery excites other astrophysicists about the robust power of ground-based telescopes and speckle imagers – a key to opening new observational windows,” said Howell. “This can help unlock the great mysteries in our universe.”

Apart from the challenges of capturing the images of the companion star, with the title of “Siwarha" for now, astronomers were also working on a short timeframe before its orbit around Betelgeuse took it even further into the main star's glare. 

There's a great read about this discovery at the NASA website here

Vera C. Rubin Observatory spotted Interstellar Comet 3I/ATLAS before it was discovered

Strange things certainly happen in astronomy!

The Vera C. Rubin Observatory has stunned the world over the last few weeks with its widefield deep-sky images. This massive telescope is already producing unparalleled  amounts of astronomical data, that will without doubt reveal the unexpected in our Universe. These discoveries could take years to uncover in the data.

Interstellar Comet 3I/ATLAS, captured by the Vera Rubin observatory on July 3rd. Image: C.O. Chandler et al.

For example, analysis of images from the new telescope have found the recently found visitor to the Solar System, Interstellar Comet 3I/ATLAS, was captured by Vera C. Rubin on the 21st of June 2025, some ten days before it was observed by the ATLAS facility and its discovery announced.  You can read more on this here.

NASA Fixes an astronomy camera from 595 million km away

One of the big problems with space missions, especially those heading on long journeys to explore outer planets, is the damage that Solar radiation can cause to sensitive computer electronics and camera sensors. Even with the best precautions, unexpected problems can occur, and they can put entire missions at risk.

NASA encountered just that with its Juno mission to Jupiter. JunoCam, a high resolution, visible light camera, started to deteriorate due to the high radiation environment around the gas giant. 

Image from JunoCam showing noise due to radiation damage to the camera sensor. Image via: NASA/JPL-Caltech/SwRI/MSSS

A work around was presented last week at the Institute of Electrical and Electronics Engineers Nuclear & Space Radiation Effects Conference in Nashville. The never tried before solution? Turn up the heater and try to re-anneal the surface of the sensor. 

“We knew annealing can sometimes alter a material like silicon at a microscopic level but didn’t know if this would fix the damage,” said JunoCam imaging engineer Jacob Schaffner of Malin Space Science Systems in San Diego, which designed and developed JunoCam and is part of the team that operates it. “We commanded JunoCam’s one heater to raise the camera’s temperature to 77 degrees Fahrenheit — much warmer than typical for JunoCam — and waited with bated breath to see the results.”

This long-distance gamble seems to have restored much of JunoCam's capabilities, at least in the short term. Read more about this camera repair here. 

Cheers,

Earl White 

BINTEL

26th July 2025