Month: June 2024

A Nova Will Explode This Summer (Probably)

/ Dr.Tony Phillips / Leave a comment

June 7, 2024: The night sky is about to get a new star. Sometime this summer, astronomers believe, a nova will explode in the constellation Corona Borealis (the Northern Crown). The exploding star will be bright enough to see with the naked eye even from light-polluted cities.


Above: A NASA artist’s concept of the T CrB binary star system

“It’s a once-in-a-lifetime event,” says Rebekah Hounsell of NASA’s Goddard Space Flight Center. “I believe it will create a lot of new astronomers out there.”

T Coronae Borealis (T CrB) is a binary system 3,000 light-years from Earth. It consists of a white dwarf orbiting an ancient red giant. Hydrogen from the red giant is being pulled down onto the surface of the white dwarf, accumulating toward a critical mass. Eventually, it will trigger a thermonuclear explosion.

The outburst will be brief. Once it erupts, the nova will be visible to the naked eye for a little less than a week – but Hounsell is confident it will be quite a sight to see. The expected magnitude is between +2 and +3, similar to stars in the Big Dipper.

“Typically, nova events are faint and far away,” says Elizabeth Hays, chief of the Astroparticle Physics Laboratory at NASA Goddard. “This one will be really close, with a lot of eyes on it. We can’t wait to get the full picture of what’s going on.”

A Red Blob in the Night Sky

/ Dr.Tony Phillips / Leave a comment

April 10, 2024: This is starting to happen a lot in the state of Texas. On April 10th, around 2:14 in the morning, amateur astronomer Abdur Anwar looked up from Big Bend National Park and saw a glowing red blob glide across the starry sky. “I photographed it using my Google Pixel 6a phone in night mode,” he says.

“Is this a new aurora phenomenon?” he asks.

No, it’s SpaceX.

About 90 minutes before the red blob appeared, a Falcon 9 rocket lifted off from the Cape Canaveral Space Force Station in Florida, carrying 23 Starlink satellites to low-Earth orbit (Starlink Group 6-48). After the satellites were deployed, the rocket’s second stage executed a de-orbit burn, creating the nearly-spherical red light.

It’s not the first time sky watchers have noticed this phenomenon. “We are seeing 2 to 5 of them each month,” reports Stephen Hummel of the McDonald Observatory in Texas, who photographed a spectacular example last November.

The red glow is created by a chemical reaction. De-orbiting Falcon 9 rocket engines spray water (H2O) and carbon dioxide (CO2) into the upper atmosphere–as much as 400 lbs of exhaust gasses. A complicated series of charge exchange reactions between these molecules and O+ atoms produces red light at a wavelength of 6300 Å–coincidentally, the same color as red auroras.

Texas seems to be a great place to observe the phenomenon; most sightings have come from there or neighboring states. Texas is favored because, for Starlink missions launched from Florida, it’s approximately where a de-orbit burn will splash the rocket’s second stage safely into the South Atlantic. The burns happen about 90 minutes after launch–just when Anwar saw the blob.

Would you like to see one? Check the SpaceX schedule for night launches, then look at the sky 90 minutes after liftoff. Human eyes are not very sensitive to the 6300 Å wavelength of the red glow, but cameras have no such trouble. Take a short nighttime exposure and submit your images here.

more images: from Madison J Post near Animas, NM