Astronomers utilizing the NASA/ESA Hubble Space Telescope have captured breathtaking new images of the blue, compact dwarf galaxy Markarian 178.
This Hubble image showcases the blue compact dwarf galaxy Markarian 178. Image credit: NASA / ESA / Hubble / F. Annibali / S. Hon.
Markarian 178 is situated roughly 13 million light years away in the constellation Ursa Major.
This galaxy, commonly referred to as Mrk 178, LEDA 35684, and UGC 6541, spans a diameter of 5,700 light years.
“MRK 178 is one of over 1,500 Markarian galaxies,” stated Hubble astronomers.
“These galaxies are named after Benjamin Markarian, an Armenian astrophysicist who compiled a catalog of galaxies that exhibit unusual brightness in ultraviolet light.”
“While most galaxies appear blue due to a plethora of young, hot stars and minimal dust, Mrk 178 presents a reddish hue. This concentration of massive stars is particularly abundant in the brightest, reddish areas near the galaxy’s edge.”
“This azure nebula houses numerous unique entities known as Wolf Rayet stars.”
“A Wolf-Rayet star is a massive star whose atmosphere is expelled by intense stellar winds,” the astronomers clarified.
“Mrk 178 features such an abundance of Wolf-Rayet stars that vivid emission lines from the hot stellar winds of these stars are inscribed into the galaxy’s spectrum.”
“In this image, captured using some of Hubble’s specialized optical filters, ionized hydrogen and oxygen are notably represented as red in Mrk 178.”
“Massive stars transition into the Wolf-Rayet stage immediately before collapsing into a black hole or neutron star.”
“We understand that some event must have instigated Mrk 178’s recent surge in star formation, as Wolf-Rayet stars have lifespans of merely a few million years.”
“At first glance, it remains uncertain what is instigating this phenomenon. Mrk 178 does not appear to have any neighboring galaxies that could disrupt its gas and promote new star formation.”
“Instead, we hypothesize that either a gas cloud collided with Mrk 178, or that the gas was affected as the galaxy traversed through the intergalactic medium, energizing this small galaxy with waves of brilliant new stars.”
New research published on Monday indicates that the number of structures in the United States vulnerable to flooding may be greater than previously estimated.
A study, published in the Journal’s Future of Earth, revealed that 43% of North Carolina’s flooded buildings from 1996 to 2020 are outside the Federal Emergency Management Agency’s Special Flood Hazard Areas, which FEMA designates as having a 1% chance of flooding in any given year.
Experts and the study’s authors believe these findings may assist more communities in understanding their flood risks and insurance needs. As companies pull back from increasing insurance premiums and insuring homes in certain regions due to more frequent severe weather, obtaining flood insurance is becoming increasingly challenging, leaving property owners more exposed.
According to NBC News, experts stated that having access to reliable data sources could facilitate the creation of nationwide databases like the one outlined in the study.
FEMA’s maps serve as the main reference for identifying flood-prone zones and structures requiring insurance coverage. However, experts argue that this system is outdated and lacks resolution. A 100-year floodplain projection doesn’t fully encompass the areas that could be at risk for flooding, and the authors noted that climate change has compromised the reliability of previously authoritative weather and climate forecasts.
This study enabled researchers to pinpoint specific structures that have experienced multiple flooding incidents by utilizing address-level data. This information could inform property owners on whether to obtain flood insurance, even if they fall outside FEMA’s designated flood hazard zones. In the United States, FEMA reports that 99% of counties have experienced flooding, yet only 4% of homeowners hold flood insurance at least once.
“Detailed information about previously flooded areas can empower individuals to make informed decisions,” expressed Helena Margaret Garcia, the lead author of the study and a doctoral candidate at the University of North Carolina Chapel Hill.
FEMA and the National Flood Insurance Program did not respond to requests for comments.
FEMA is currently working on revamping its flood mapping system through the Future of Flood Risk Data initiative, aimed at employing more efficient, accurate, and consistent technology to assess the country’s flood risks comprehensively.
Water markers in Orocoke, North Carolina homes illustrate the increasing severity of flooding between hurricanes over time. Courtesy of Helena Garcia
As global temperatures rise, more intense rainfall events are becoming common since warmer air can hold more moisture. Climate change has also contributed to rising sea levels, increasing vulnerability to flooding even in coastal and some inland areas. Hurricane Helen, the third deadliest hurricane of modern times, inflicted substantial flooding in North Carolina’s mountainous regions. Damage from the storm exceeded a total of $78 billion, according to the National Oceanic and Atmospheric Administration.
The recent severe rainfall has caused flash floods across many U.S. towns over the last two weeks, most recently impacting towns in New Jersey and New York City. In North Carolina alone, six deaths have been reported, while over 100 fatalities have occurred in Texas. Flash floods have historically accounted for the highest number of storm-related deaths in the U.S., averaging 125 deaths per year over recent decades, according to the National Weather Service.
A North Carolina climate scientist noted that the warm seawater feeding the storm could have been a contributing factor to last week’s Tropical Storm Chantal, which set rainfall and river level records in the state.
With the impacts of climate change, having access to up-to-date maps is essential, experts argue.
In their study, researchers mapped 78 flood events using data from 1996 to 2020 from the National Flood Insurance Program, which allows property owners to purchase insurance for potential flood-related losses. They also incorporated emergency service requests and volunteer-based geographic information obtained from social media, creating what they termed the “first of its kind” database. This historical flood data is often inaccessible to the public, which can hinder homeowners’ awareness of prior flood incidents affecting their properties.
Garcia stated that researchers plan to apply the same methodology from their study to create similar historical maps in various regions across the country, identifying areas previously overlooked concerning flood risk.
The research indicated that out of 90,000 structures, only 20,000 experienced flooding, highlighting a significant number that did not file NFIP claims. The study’s authors are now focused on quantifying the human impact, examining outcomes such as healthcare disruptions resulting from floods and the scale of evacuations caused by repeated flooding, as Garcia explained.
On July 7th, Eastgate Mall’s parking lot in Chapel Hill, North Carolina, was inundated following a tropical storm. Courtesy of Antonia Sebastian/Helena Garcia
Antonia Sebastian, an assistant professor in the Department of Geology at UNC-Chapel Hill, noted that the study aspires to establish a “comprehensive record of past floods” by gathering data on relatively minor flood events that impact homeowners yet do not receive widespread media attention.
“Areas that have previously flooded are likely to flood again; it’s only a matter of time,” Sebastian remarked. “These sites are inherently dangerous.”
Chad Belginis, executive director of the Flood Plains Association who was not involved in the study, stated that FEMA’s maps are intended to implement the NFIP by utilizing 100-year flood plains to delineate zones for flood insurance coverage. He emphasized that analyzing historical flood research highlights the necessity for flood insurance in areas beyond the mapped FEMA flood hazard zones.
“FEMA’s flood map serves as a starting point, not an endpoint,” Berginnis clarified. “The maps present one kind of flood risk, but to fully grasp flood risk, it is crucial to seek out historical flood data.”
He mentioned that the database models illustrated in the study could be adopted in various other regions. A community manager indicated that identifying past flood sites could enhance community awareness regarding flood risks.
“When we consider the history of floods, [like those along the Guadalupe River], it emphasizes the dangers that have persisted over time,” they reflected. “I truly believe that these areas should be acknowledged as perilous, yet awareness of the actual flooding risks is often lacking.”
June Choi, a doctoral student in Earth Systems Science at Stanford University and not involved in the study, noted that the finding regarding many flooded buildings existing outside FEMA-designated risky areas likely applies to all states. She highlighted that while new databases might have limitations regarding changing building densities over time, the application of historical records and address-specific data still provides valuable insights for assessing future flood risks.
Astronomers utilized the mid-infrared instrument (Miri) on the NASA/ESA/CSA James Webb Space Telescope to capture breathtaking infrared images of the heart of Messier 82, an edge-on starburst galaxy located approximately 12 million light-years away.
This Webb/Miri image highlights the central region of the Starburst Galaxy Messier 82. Image credits: NASA/ESA/CSA/Webb/A. Bolatto.
Messier 82 is positioned higher in the Northern Spring Sky, situated within the Ursa Major constellation’s direction.
The galaxy was first identified by German astronomer Johann Erard Bord in 1774 and is estimated to be around 40,000 light-years old.
Messier 82 is also referred to as the Cigar Galaxy due to its elongated oval shape, a result of the tilt of its stellar disk relative to our perspective.
Known for its exceptional rate of star formation, galaxies like Messier 82 generate stars ten times faster than our Milky Way.
“Though smaller than the Milky Way, Messier 82 is five times as luminous and creates stars at a rate 10 times greater,” the Webb astronomers noted.
“Classified as a Starburst Galaxy, Messier 82 is particularly active in its center, producing new stars at an accelerated pace compared to other galaxies of its size.”
In visible light images, the central region’s intense activity is concealed by a thick veil of dust clouds, but Webb’s infrared capabilities allow it to penetrate this obscuring layer and unveil the hidden dynamism.
“The reason for the star formation surge in Messier 82 likely lies with its gravitational interactions with the neighboring Spiral Galaxy Messier 81,” the astronomers remarked.
“These interactions directed gas towards the center of Messier 82 millions of years ago.”
“This influx of gas supplied essential materials for new star formation, resulting in Messier 82’s distinct structure! The galaxy boasts over 100 superstar clusters.”
“Superstar clusters are larger and more luminous than normal star clusters, each containing approximately 100,000 stars.”
Earlier Webb images of Messier 82, utilizing data from the telescope’s near-infrared camera (Nircam), were made public in 2024.
These images concentrated on the galaxy’s core, where individual clusters of young stars contrasted with gas clumps and tendrils.
The latest images from Webb’s Miri instruments provide an astonishing, almost starless view of Messier 82.
“Instead, these images highlight warm dust and a complex cloud of sooted organic molecules known as polycyclic aromatic hydrocarbons (PAHs),” the researchers explained.
“Emissions from PAH molecules trace the expansive runoff of the galaxy, propelled by intense radiation and winds from the hot young stars within the central superstar cluster.”
“Superstar clusters are responsible for Messier 82’s powerful galactic winds, which may signal the conclusion of the galaxy’s Starburst period. These winds, transforming into massive waves in intergalactic space, carry the cool gas necessary for further star formation.”
The NASA/ESA Hubble Space Telescope captured this stunning image of the Pegasus dwarf elliptical galaxy, a moon of the Andromeda galaxy.
The Pegasus dwarf elliptical galaxy is located about 959,000 light-years away from the Andromeda galaxy. Image credit: NASA / ESA / D. Weisz, University of California, Berkeley / Gladys Kober, NASA and The Catholic University of California.
“The Andromeda Galaxy, also known as Messier 31, is the closest large spiral galaxy to the Milky Way and is orbited by at least 13 dwarf moons,” Hubble astronomers said in a statement.
“The Pegasus dwarf spheroidal galaxy is one of these compact galaxies.”
“Dwarf spheroidal galaxies are the faintest and most massive galaxies known,” they explained.
“They tend to have an elliptical shape and a relatively smooth distribution of stars.”
“Dwarf spheroidal galaxies are typically devoid of gas and contain mostly old and intermediate-stage stars, although some have recently undergone a small amount of star formation.”
The Pegasus dwarf spheroidal galaxy, also known as Andromeda VI, was discovered in 1996 in images from the Second Palomar Observatory Sky Survey (POSS II).
“The galaxy is characterised by a low abundance of heavy elements, leaving very little gas needed to form the next generation of stars, although it still has more than many of the dwarf spheroidal galaxies in our Local Group,” the astronomers said.
“Researchers suspect that Andromeda's gravitational field is stripping away star-forming gas, leaving it with insufficient material to form more than a few generations of stars.”
“By comparison, some of the Milky Way's comparable distant dwarf spheroidal companions contain intermediate-age stars, which may be because the Andromeda Galaxy is so massive and extended that its gravitational influence reaches farther.”
“The jury is still out on how dwarf elliptical galaxies form,” they noted.
“Theories include collisions between galaxies that break off smaller pieces, the gravitational influence of larger galaxies on small, disk-like dwarf galaxies, and processes related to the birth of small systems among dark matter aggregates.”
“Andromeda and the Milky Way are the only galaxies close enough for astronomers to observe these faint satellite galaxies, so clues to their formation come from nearby galaxies like this one.”
“Hubble studied this galaxy as part of a survey of the entire Andromeda moon system to investigate important topics such as dark matter, reionization, and the growth of galactic ecosystems through the ages of the universe.”
Astronomers using the NASA/ESA/CSA James Webb Space Telescope have captured stunning new photos of NGC 4449, located in the constellation Canes Venatici.
This Webb/MIRI/NIRCam image shows the center of irregular galaxy NGC 4449. Image credit: NASA / ESA / CSA / Webb / A. Adamo, Stockholm University / FEAST JWST Team.
NGC 4449 It is located about 12.5 million light years away in the constellation Canes Venatici.
Also known as Caldwell 21, LEDA 40973, and UGC 7592, the galaxy has a diameter of about 20,000 light-years.
NGC 4449 discovered It was discovered on April 27, 1788 by German-born British astronomer William Herschel.
It is part of the M94 galaxy group, lie It is near the Local Group that hosts our Milky Way galaxy.
“NGC 4449 has been forming stars for billions of years, but star formation is occurring at a much higher rate today than in the past,” astronomer Webb said.
“Such unusually explosive and intense star formation activity is called a starburst, and NGC 4449 is therefore known as a starburst galaxy.”
“Indeed, at the current rate of star formation, the gas supply required for star formation will last only another billion years or so.”
“Starbursts typically occur in the centres of galaxies, but NGC 4449 shows more widespread star formation activity, with very young stars observed both in the galaxy's core and in the outflow that surrounds it.”
“The current widespread starburst is likely caused by an interaction or merger with a smaller companion star.”
“Indeed, star formation in NGC 4449 is likely influenced by interactions with several nearby stars.”
“NGC 4449 resembles a primitive star-forming galaxy that grew by merging and accreting with smaller stellar systems,” the researchers added.
“NGC 4449 is close enough for us to observe it in great detail, making it an ideal laboratory for studying what happened during the formation and evolution of galaxies in the early universe.”
This Webb/NIRCam image shows the irregular galaxy NGC 4449. Image courtesy of NASA / ESA / CSA / Webb / A. Adamo, Stockholm University / FEAST JWST Team.
NGC 4449 was observed as part of the FEAST (Feedback in Emerging extrAgalactic Star cluSTers) survey.
The image is MIRI on the Web (mid-infrared measuring instrument) and NIR Cam (Near infrared camera) equipment.
“Infrared observations reveal the galaxy's crawling tentacles of gas, dust and stars,” the astronomers said.
“The bright blue dots reveal countless individual stars, while the bright yellow regions spread across the galaxy show concentrated active stellar nurseries where new stars are forming.”
“The orange-red areas show the distribution of a type of carbon-based compound known as polycyclic aromatic hydrocarbons (PAHs). The MIRI F770W filter is particularly well suited to imaging these important molecules.”
“The bright red spots correspond to hydrogen-rich regions that have been ionized by radiation from newly formed stars.”
“The diffuse gradient of blue light around the central region indicates the distribution of old stars.”
“The compact light blue regions within the red ionized gas are concentrated mainly in the outer regions of the galaxy and represent the distribution of young star clusters.”
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