Mapping stellar nurseries in the Milky Way

Mapping stellar nurseries in the Milky Way
Spatial distribution of YSO candidates groups (red circles) in the Solar neighborhood. The Sun is represented by the yellow symbol in the center, and the segments of the Galactic disk that have been included in the SPICY study are white, while the others are gray. The approximate positions of the Milky Way’s spiral arms are shown in darker gray. Credit: Cosmostatistics Initiative

An international team of Astronomers from the Cosmostatistics Initiative (COIN) identified nearly 120,000 new young stellar objects (YSOs) based on data from the Infrared Array Camera of NASA’s Spitzer Space Telescope. The final catalog, named SPICY (Spitzer/IRAC Candidate YSO Catalog), is publicly available to anyone who wishes to study the first stages of stellar development.

Stars are the building blocks of all structures in our universe. They are responsible for producing the more complex chemical elements, spreading them through space, igniting the formation of planets and ultimately, forming the necessary environment for the development of life. Understanding the earlier stages of stellar evolution is the first step towards a better comprehension of how our own Sun was formed and may provide important clues on which regions of our Milky Way have the potential to host planetary systems similar to our own.

The Spitzer Space Telescope devoted significant time to scanning large areas of our Galaxy in a hunt for YSOs. Our galaxy is shaped like a disk, with both our Sun and star-forming regions located inside the disk, meaning that most star-forming regions can be found in a thin strip that circles the sky. During an observing campaign named GLIMPSE, Spitzer took high resolution images of this strip revealing tens of millions of stars. However, this posed another very difficult question: how to find young stars among the tens of millions of objects present in such a large data set?

Mapping stellar nurseries in the Milky Way
Infrared Spitzer images centered on several YSO candidates. Nebulosity is found around many of the objects. A few of the stars may be difficult to see due to the high contrasts that must be accommodated in making these false-colored images. Credit: Cosmostatistics Initiative

To solve this puzzle, members of the Cosmostatistics Initiative employed a classification scheme that uses the flexibility of cutting edge machine learning and curated YSO datasets to take full advantage of IRAC’s spatial resolution and sensitivity in the mid-infrared ∼3–9 μm range. Multi-wavelength color/magnitude distributions provide intuition about how the classifier separates YSOs from other red IRAC sources and validate that the sample is consistent with expectations for disk/envelope-bearing pre–main-sequence stars.

Mapping stellar nurseries in the Milky Way
Spatial distribution of the SPICY YSO candidates among the constellations of the Milky Way. Credit: Cosmostatistics Initiative

Located in the inner region of the Galactic midplane, most of the candidates are in regions with mid-IR nebulosity, associated with star-forming clouds, but others appear distributed in the field. Using distance estimates from the ESA Gaia satellite, the researchers found groups of YSO candidates associated with the Local Arm, the Sagittarius-Carina Arm, and the Scutum-Centaurus Arm. Candidate YSOs visible to the Zwicky Transient Facility tend to

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Megalodons, the Ocean’s Most Ferocious Prehistoric Predators, Raised Their Young in Nurseries | Smart News

Millions of years ago, monstrously sized sharks named megalodons dominated the ocean. These giants grew larger than modern day humpback whales, casually snacked on animals like dolphins and seals, had the strongest bite force of any creature to ever exist—yes, including T. rex. But despite being fierce predators, a new study published last week in the journal Biology Letters suggests that megalodons were pretty good parents and raised their young in nurseries, reports Mindy Weisberger for Live Science.

Nurseries provide a safe haven for baby sharks to grow before they depart to take on the great blue sea. They are typically found in warm, shallow waters, such as coral reefs and mangroves, that offer an abundance of food. Nurseries also shield baby sharks from predators and protect them as they learn to hunt, reports Melissa Cristina Márquez for Forbes. And this behavior didn’t die out with the megalodons—some modern-day shark species, like great whites and catsharks, also raise their young in nurseries.

“I just find it fascinating that even what many call the ‘biggest and baddest shark of all time’ had to spend the first few years of its life growing up in a special location before it could dominate the oceans itself,” Phillip Sternes, a shark researcher at University of California, Riverside, who was not involved in the study, tells Forbes.

In this new study, a team of scientists analyzed a set of 25 megalodon teeth collected around northeastern Spain. The teeth were much too small to belong to the fully grown giants, so the scientists figured that the teeth must have belonged to juveniles, reports Lucy Hicks for Science. Fossil evidence also suggests that millions of years ago, the same region had shallow shorelines, warm water and flourishing marine life, which would have made it a perfect place for baby sharks to thrive. Given the collection of baby teeth and the geography of the area, the scientists determined that a megalodon nursery must have existed there, reports Eleonore Hughes for Agence France-Presse (AFP).

Armed with new information about megalodon shark nurseries, the scientists analyzed nearly 500 more megalodon teeth collected from eight different spots around the world to figure out where other nurseries could have existed. They identified four more potential nursery sites—two in the United States and two in Panama—ranging in age from 3.6 million years old to 16 million years old.

In 2010, a different team, including Smithsonian Tropical Research Institute scientists, discovered a megalodon nursery in Panama from 10 million years ago. At the time, the team wasn’t sure if megalodon nurseries were widespread or a random occurrence. This new study adds substantial evidence that baby megalodons were raised in nurseries, Science reports.

This discovery also offers a new theory to how the world’s most ferocious predator went extinct more than 3 million years ago, which remains a pervasive mystery. They know that megalodons thrived during a period of warm temperatures that lasted for millions of years. But as

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Megalodon nurseries reveal world’s largest shark had a soft side

The enormous, extinct shark Megalodon probably doesn’t make you think of parenting and playdates. But a growing body of evidence suggests that these massive marine predators nurtured their babies by raising them in nurseries, and scientists just added five potential Megalodon nurseries to the list. 

a bird flying over a body of water: Megalodon, the biggest predatory shark of all time, watched over its young as many modern sharks do — by raising them in defined geographic areas known as nurseries.

© Provided by Live Science
Megalodon, the biggest predatory shark of all time, watched over its young as many modern sharks do — by raising them in defined geographic areas known as nurseries.

These baby-shark grounds are showing up all over. Scientists reported in 2010 that they had identified a Megalodon nursery in Panama. Recently, another team of researchers described a new Megalodon nursery site in northeastern Spain; fossils of fully grown sharks and youngsters were found together, with most of the fossils belonging to juveniles and newborns. 


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Those same scientists also analyzed data from eight other sites — from 16 million to 3 million years ago — where Otodus megalodon fossils were plentiful. They evaluated the body sizes of individual sharks to determine the ratio of juveniles to adults, and named four additional nursery sites. 

The results suggest that Megalodon adults commonly raised their young in nursery areas, where the wee shark babies would be protected until they were able to fend for themselves against other ocean predators. It also raises the possibility that the decline of available nursery sites may have contributed to the giant shark’s extinction, according to a new study.

Related: Photos: These animals used to be giants

O. megalodon is estimated to have measured up to 50 feet (15 meters) in length, making it the biggest predatory shark that ever lived. Most Megalodon fossils date to about 15 million years ago, and the giant fish vanished from the fossil record about 2.6 million years ago.

Today, many modern sharks raise their young in nurseries. Waters near northern Patagonia’s Buenos Aires province hold a nursery for several shark species, and a nursery of sand tiger sharks (Carcharias taurus) in Long Island’s Great South Bay hosts juvenile sharks that live there until they are 4 or 5 years old. And the oldest known shark nursery is more than 200 million years old, according to fossilized egg cases found alongside shark “baby teeth” that are just 0.04 inches (1 millimeter) long, Live Science previously reported.

For the new study, the researchers investigated 25 teeth belonging to O. megalodon  from the Reverté and Vidal quarries in Spain’s Tarragona province. They used tooth crown height to estimate body size and to identify which of the sharks were babies; very young sharks — likely about one month old — that measured about 13 feet (4 m) long, and older juveniles measured up to 36 feet (11 m) in length. 

The scientists then used algorithms to model and compare the ratio of O. megalodon juveniles to adults at eight other sites across “a wide geographical area” that included the Atlantic, Caribbean and Pacific basins. They determined five potential nurseries “with higher densities of

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