Tag Archives: protostars

A Remarkably Tight Cluster of Protostars Likely Discovered

Posted on by
Reply

Artist’s rendition of a Population III star that existed 100 million years after the Big Bang

Noir Lab/NSF/AURA/J. da Silva/Space Engine/M. Zamani

We may have finally observed the first generation of stars. After decades of searching for these pristine giants, known as Population III stars, astronomers have found their most promising candidate yet.

Population III stars are anticipated to be markedly distinct from today’s stars, or Population I stars. They are believed to have formed from pure hydrogen and helium gases before supernovae and powerful stellar winds dispersed heavier elements across the universe. These stars are also predicted to be larger and hotter than modern counterparts.

That’s precisely the case, according to Eli Visbal. Researchers from the University of Toledo in Ohio made this discovery through a detailed examination of prior James Webb Space Telescope (JWST) observations of a distant galaxy known as LAP1-B. With a redshift of 6.6, this galaxy is visible approximately 800 million years after the Big Bang. Its discovery was facilitated by the magnification of its light due to gravitational lensing by nearby galaxy clusters.

“There’s likely much more to discover in the universe, but we can only see it illuminated by this expanding star cluster,” Visbal noted. When his team estimated how many Population III clusters could exist at this redshift, they figured there should be only one—exactly what they observed. “Our abundance calculations aligned perfectly with those of the previous research team,” he added.

Another advantage of LAP1-B is that it contains only enough stars to comprise several thousand times the mass of the Sun. In contrast, other Population III galaxy candidates usually have significantly larger stellar masses, which do not align with simulations of Population III cluster formation. “This is the most robust candidate we’ve encountered,” says Visbal.

Most Population III stars are thought to have existed and perished between about 100 million and 400 million years after the Big Bang, at which point there were enough heavy elements in the universe to create stars similar to those we observe today. “This object meets many criteria, but I remain somewhat skeptical because these stars emerge later in the timeline, and there may be other viable explanations,” remarks Ralph Cressen from the University of Heidelberg, Germany. “Discovering Population III clusters would be fascinating, but statistically, this would surely be an anomaly.”

However, primordial pockets of hydrogen and helium could linger longer, potentially leading to the formation of Population III stars, as Visbal suggested.

“LAP-B1 is a particularly intriguing candidate, but we are still far from the clear and undeniable indications we would need for definite identification of Population III,” comments Roberto Maiorino at Cambridge University. “[For these to truly be Population III stars] it requires an extremely fortunate combination of factors, each of which is quite rare on its own, and even rarer when they occur together. Further observations and in-depth simulations are essential to ascertain whether LAP1-B represents the first detection of these enigmatic stars.

Understanding Population III stars is crucial, as they offer insights into the formation of the universe’s first heavy elements. “They reveal how the universe’s chemistry evolved from being solely hydrogen and helium to the diverse range of chemicals, life, and entities that exist today,” Visbal states. The stars of Population III were the pioneering building blocks of the complexity encompassing us now.

Topics:

Source: www.newscientist.com

Two protostars spotted by Hubble in the Orion Nebula

Posted on by
Reply

A new image from the NASA/ESA Hubble Space Telescope shows two protostars in the Orion Nebula, a diffuse nebula located about 1,350 light-years away in the constellation Orion.

This Hubble image shows two protostars, HOPS 150 and HOPS 153, within the famous Orion Nebula. Image credit: NASA / ESA / Hubble / T. Megeath.

The Orion Nebula is visible to the naked eye as a fuzzy speck surrounding the Hunter's Sword star Theta Orionis, below Orion's belt.

This nebula has been known as a star since the beginning of astronomical records, but it is so remarkable that it was first recognized as an expanded nebula in 1610, just one year after Galileo Galilei first used a telescope. It got attention.

Detailed descriptions of the Orion Nebula began to appear in the late 17th century, and it has been a popular target for anyone with a telescope ever since.

Also known as NGC 1976, Messier 42, M42, LBN 974, and Sharpless 281, this nebula is about 24 light-years long.

Only two million years old, this object is an ideal laboratory for studying young and nascent stars.

It offers a glimpse of what happened when the sun was born 4.6 billion years ago.

“The Orion Nebula is home to hundreds of newborn stars, including the protostars HOPS 150 and HOPS 153, the subject of this image,” Hubble astronomers said in a statement.

“The names of these protostars come from the Herschel Orion Protostar Survey, conducted in collaboration with ESA's Herschel Space Observatory.”

“The object visible in the upper right corner of this image is HOPS 150. It is a binary star system, with two young protostars orbiting each other.”

“Each animal has a small dusty disk around it from which it gets its nutrition.”

“A dark line across the bright glow of these protostars is a cloud of gas and dust more than 2,000 times wider than the distance between Earth and the Sun that dips into the pair of protostars.”

“Based on the amount of infrared light emitted by HOPS 150 and the light at other wavelengths, we can see that the protostar is on its way to becoming a mature star.”

“Extending to the left of the image is a narrow, colorful outflow called a jet. This jet comes out of frame from the nearby protostar HOPS 153,” they said.

“HOPS 153 is a much younger object than its neighbors, still deeply embedded in its birth nebula and shrouded in a cold, dense cloud of gas.”

“Hubble can't penetrate this gas to see protostars, but the jets released by HOPS 153 appear bright as they plow into the gas and dust surrounding the Orion nebula.”

“The transition from a tightly wrapped protostar to a full-fledged star will have a dramatic impact on the surroundings of HOPS 153.”

“When gas falls into a protostar, its jets spew matter and energy into interstellar space, creating bubbles and heating the gas.”

“By stirring up and warming nearby gas, HOPS 153 may control the formation of new stars in its vicinity and even slow its own growth.”

Source: www.sci.news

Webb discovers complex organic compounds in interstellar ice approaching dual protostars

Posted on by
Reply

astronomer using Mid-infrared measuring instrument The NASA/ESA/CSA James Webb Space Telescope's (MIRI) detected molecules ranging from relatively simple ones like methane to complex compounds like ethanol (alcohol) and acetic acid. interstellar ice One low-mass protostar and one high-mass protostar: toward NGC 1333 IRAS 2A and IRAS 23385+6053, respectively.

This image taken by Webb's MIRI instrument shows the region near the IRAS 23385+6053 protostar. Image credit: NASA/ESA/CSA/WRM Rocha, LEI.

Complex organic molecules (COM) are molecules with six or more atoms, including at least one carbon atom.

These materials are the raw material for future exoplanetary systems and are therefore of essential importance in understanding the chemical complexity developed in star-forming regions.

If this material becomes available in a primitive planetary system, it could facilitate the planet's habitability.

In a new study, astronomers Will Rocha, Harold Linnaerts and colleagues at Leiden University used Webb's mid-infrared instrument to determine the extent of COM ice in two protostars, NGC 1333 IRAS 2A and IRAS 23385+6053. We investigated the characteristics.

They were able to identify a variety of COMs, including ethanol (alcohol) and perhaps acetic acid (a component of vinegar).

“Our discovery contributes to one of the long-standing questions in astrochemistry,” Dr. Rocha said.

“What is the origin of COM in the Universe?” Are they created in the gas phase or in ice? Detection of COM in ice is based on the solid phase at the surface of cold dust particles It suggests that chemical reactions can build complex types of molecules. ”

“Some COMs, including those detected in the solid phase in our study, were previously detected in the warm gas phase, so they are now thought to originate from ice sublimation.”

“Sublimation is the change from a solid directly to a gas without becoming a liquid.”

“Therefore, we have hope that detecting COM in ice will improve our understanding of the origins of other, larger molecules in the universe.”

This figure shows the spectrum of the NGC 1333 IRAS 2A protostar. Image credit: NASA/ESA/CSA/Leah Hustak, STScI.

The researchers also detected simpler molecules such as formic acid, methane, formaldehyde, and sulfur dioxide.

“Sulfur-containing compounds, such as sulfur dioxide, played an important role in promoting metabolic reactions on early Earth,” the researchers said.

“Of particular interest is that one of the investigated origins, NGC 1333 IRAS 2A, is characterized as a low-mass protostar.”

“NGC 1333 IRAS 2A may resemble the early stages of our solar system.”

“Therefore, the chemicals identified around this protostar may have been present during the earliest stages of the development of the solar system and were later delivered to the proto-Earth.”

“All of these molecules could become part of comets, asteroids, and ultimately new planetary systems as icy material is transported inside planet-forming disks as protostar systems evolve.” '' said Dr. Ewain van Dyschoek, an astronomer at Leiden University.

“We look forward to using more web data in the coming years to follow this astrochemical trajectory step by step.”

of the team paper It was published in the magazine astronomy and astrophysics.

_____

WRM Rocha other. 2024. JWST Young Protostar Observation (JOYS+): Detection of icy complex organic molecules and ions. I.CH.FourSo2,HCOO−,OCN−,H2Colorado, Cooh, Switzerland3CH2Oh, CH3Cho, channel3Ocho and CH3Coo. A&A 683, A124; doi: 10.1051/0004-6361/202348427

Source: www.sci.news