Tag Archives: obscure

How Star-Induced ‘Space Weather’ Could Obscure Radio Signals from Extraterrestrial Civilizations

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Stellar activity and plasma turbulence can significantly distort narrow radio signals before they exit their planetary systems. This phenomenon may help explain the prolonged silence observed in the search for extraterrestrial intelligence (ETI).

Research by Vishal Gajjar and Grayce C. Brown introduces one of the first quantitative frameworks to assess how stellar environments affect the detectability of narrowband technosignatures. Image credit: Sci.News.

In our exploration of technosignatures, astronomers typically take into account the distortions that occur as radio waves traverse interstellar space.

Variations in plasma density from stellar winds and sporadic eruptive events like coronal mass ejections can severely distort radio waves near their source, effectively “smearing” the frequency and diminishing the peak intensity necessary for detection.

“SETI searches are usually optimized for very narrow signals,” stated Dr. Vishal Gajjar, an astronomer at the SETI Institute.

“If a signal is amplified by its stellar environment, it might drop below the detection threshold, potentially elucidating some of the radio silence encountered in the search for technosignatures.”

To quantify this effect, Dr. Gajjar and his colleague Dr. Grace Brown leveraged directly measurable data: radio transmissions from spacecraft within our solar system.

They utilized empirical data from solar system probes to calibrate how turbulent plasma disperses narrowband signals, extrapolating these findings across various stellar environments.

The outcome is a comprehensive framework for estimating the extent of signal broadening across different star types and observation frequencies, particularly under “space weather” conditions prevalent around active stars.

This groundbreaking study has significant implications for target selection and search design in SETI.

M-type dwarfs, which constitute approximately 75% of stars in the Milky Way, are particularly prone to having narrowband signals distorted before departing their systems.

Astronomers advocate for search strategies that maintain sensitivity, even when the detected signal is not purely ultrathin.

“By quantifying how stellar activity alters narrowband signals, we can create searches that more accurately reflect what actually arrives on Earth, not just what may be transmitted,” noted Dr. Brown.

The team’s research was published on March 5th in the Astrophysical Journal.

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Vishal Gajjar and Grace C. Brown. 2026. Exo-IPM scattering as a hidden gatekeeper of narrowband technology signatures. APJ 999, 201; doi: 10.3847/1538-4357/ae3d33

Source: www.sci.news

Hubble Captures Breathtaking Images of Obscure Planet Nebula

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Officially named Kohoutek 4-55, this little-known planetary nebula is located within our Milky Way galaxy.

This Hubble image shows Kohoutek 4-55, a nebula of planets 4,600 light years away in the Cygnus constellation. Image credits: NASA/ESA/Hubble/K. Noll.

“The Nebula of Planets is a spectacular final exhibition at the end of the life of a giant star,” Hubble Astherm said in a statement.

“When the giant red star runs out of available fuel and flows the final gas layer, its compact core shrinks further, allowing for a final burst of fusion.”

“The exposed core reaches very high temperatures and emits very energetic UV rays, activating a huge cloud of casting gas.”

“Molecules in the gas are ionized and brighten.”

“Here, red and orange represent nitrogen molecules, green represent hydrogen, and blue represent nebulae oxygen.”

Kohoutek 4-55 is located approximately 4,600 light years away from the Cygnus constellation.

Also known as UHA 15 or G084.2+01.0, this nebula has an unusual multilayered form.

“The bright inner ring of the Kohoutek 4-55 is surrounded by a loose layer of gas, all wrapped in a wide halo of ionized nitrogen,” the astronomer said.

“The view is bittersweet. The short phase of the fusion of the cores ends tens of thousands of years, leaving behind a white dwarf who will never illuminate the surrounding clouds again.”

This image of Kohoutek 4-55 was captured by Hubble’s Widefield and Planetary Camera 2 (WFPC2).

“Installed in 1993 to replace the original Widefield and Planetary Camera (WFPC), WFPC2 was responsible for some of Hubble’s most persistent images and fascinating discoveries,” the researchers said.

“It was replaced in 2009 by Widefield Camera 3 (WFC3) during Hubble’s final service mission.”

“The data in this image was collected 10 days before the instrument was removed from the telescope, as a proper postponement for WFPC2,” he said.

“The latest and most advanced processing techniques are used to bring data to life once more, creating this breathtaking new view of Kohoutek 4-55.”

Source: www.sci.news

Hubble Space Telescope captures photo of obscure barred spiral galaxy

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Astronomers have created a beautiful image of the barred spiral galaxy UGC 11861 using the NASA/ESA Hubble Space Telescope.

This Hubble Space Telescope image shows UGC 11861, a barred spiral galaxy in the constellation Cepheus, 69 million light-years from Earth. Image credit: NASA / ESA / Hubble / C. Kilpatrick.

11861 posts It is located in the northern constellation Cepheus and is about 69 million light years away from Earth.

The galaxy, also known as LEDA 67671, IRAS 21557+7301, or TC 609, is classified as a barred spiral galaxy and a candidate active galactic nucleus.

UGC 11861 is Composed It consists of an exponential disk, a central box-shaped structure, and two broad spiral arms.

“The galaxy is actively forming new stars amidst clouds of gas and dark dust grains, visible as glowing blue spots in the outer arms,” ​​Hubble astronomers said in a statement.

“As a result of this activity, three supernova explosions have been observed in and near UGC 11861, in 1995, 1997, and 2011.”

“The first two were both Type II supernovae, the kind that result from the collapse of a massive star at the end of its life.”

“This Hubble image was made from data collected to study a Type II supernova and its environment.”

The color image of UGC 11861 was created from images taken separately in the visible and near-infrared regions of the spectrum. Hubble’s Advanced Camera for Surveys (ACS).

Two filters were used to sample different wavelengths, and color was generated by assigning a different hue to each monochromatic image associated with an individual filter.

“UGC 11861 is located 69 million light-years from Earth, which may seem a very long distance, but it was just the right distance for the Hubble Space Telescope to capture this spectacular photo of the galaxy’s spiral arms and the short, bright bar at its center,” the astronomers wrote.

Source: www.sci.news