London: Neptune, a very cold planet with average temperature reaching around minus 220 degrees Celsius, has seen rapid and unexpected temperature variations in the last two decades, scientists have found.Using ground-based telescopes, including the European Southern Observatory's Very Large Telescope (ESO's VLT), an international team of astronomers tracked Neptune's atmospheric temperatures over a 17-year period.They found a surprising drop in Neptune's global temperatures followed by a dramatic warming at its south pole."This change was unexpected," said Michael Roman, a postdoctoral research associate at the University of Leicester, UK."Since we have been observing Neptune during its early southern summer, we expected temperatures to be slowly growing warmer, not colder," he added.Like Earth, Neptune experiences seasons as it orbits the Sun. However, a Neptune season lasts around 40 years, with one Neptune year lasting 165 Earth years. It has been summer in Neptune's southern hemisphere since 2005.Despite the onset of southern summer, the data published in The Planetary Science Journal, showed that most of the planet had gradually cooled over the last two decades. The globally averaged temperature of Neptune dropped by 8 degrees Celsius between 2003 and 2018.The astronomers were also surprised to discover a dramatic warming of Neptune's south pole during the last two years of their observations, when temperatures rapidly rose 11 degrees Celsius between 2018 and 2020.Although Neptune's warm polar vortex has been known for many years, such rapid polar warming has never been previously observed on the planet.While the astronomers do not know yet what could have caused such unexpected temperature variations, they believe it could be due to changes in Neptune's stratospheric chemistry, or random weather patterns, or even the solar cycle.As Neptune is roughly 4.5 billion km away and is very cold, measuring its temperature from Earth is no easy task.To piece together overall trends in the planet's temperature the astronomers looked at nearly 100 thermal-infrared images of Neptune, captured over a 17-year period.Around one third of all the images taken came from the VLT Imager and Spectrometer for mid-InfraRed (VISIR) instrument on ESO's VLT in Chile's Atacama Desert. The team also used data from NASA's Spitzer Space Telescope and images taken with the Gemini South telescope in Chile, as well as with the Subaru Telescope, the Keck Telescope, and the Gemini North telescope, all in Hawaii. The astronomers investigated infrared light emitted from a layer of Neptune's atmosphere called the stratosphere. This allowed the team to build up a picture of Neptune's temperature and its variations during part of its southern summer. —IANS

 Neptune, a very cold planet with average temperature reaching around minus 220 degrees Celsius, has seen rapid and unexpected temperature variations in the last two decades, scientists have found.

Astronomers Find Rapid, Unexpected Changes In Neptune's Temperatures

Sydney: An Australian team of astronomers have found a slimmer type of red giant star for the first time. These stars have undergone dramatic weight loss, possibly due to the presence of a greedy neighbour.Published in Nature Astronomy, the discovery is an important step forward to understanding the life of stars in the Milky Way -- our closest stellar neighbours.There are millions of 'red giant' stars found in our galaxy. These cool and luminous objects are what our Sun will become in four billion years. For some time, astronomers have predicted the existence of slimmer red giants."We were extremely lucky to find about 40 slimmer red giants, hidden in a sea of normal ones. The slimmer red giants are either smaller in size or less massive than normal red giants," said lead author, doctoral candidate Yaguang Li from the University of Sydney.Most stars in the sky are in binary systems -- two stars that are gravitationally bound to each other. When the stars in close binaries expand, as stars do as they age, some material can reach the gravitational sphere of their companion and be sucked away."In the case of relatively tiny red giants, we think a companion could possibly be present," Li said. The team analysed archival data from NASA's Kepler space telescope. From 2009 to 2013, the telescope continuously recorded brightness variations on tens of thousands of red giants.Using this incredibly accurate and large dataset, the team conducted a thorough census of this stellar population, providing the groundwork for spotting any outliers.Two types of unusual stars were revealed: very low-mass red giants, and under luminous (dimmer) red giants.The very low-mass stars weigh only 0.5 to 0.7 solar mass - around half the weight of our Sun. If the very low-mass stars had not suddenly lost weight, their masses would indicate they were older than the age of the Universe - an impossibility."So, when we first obtained the masses of these stars, we thought there was something wrong with the measurement," Li said. "But it turns out there wasn't."The under-luminous stars, on the other hand, have normal masses, ranging from 0.8 to 2.0 solar mass."However, they are much less 'giant' than we expect," said co-author Dr Simon Murphy from the University of Southern Queensland."They've slimmed down somewhat and because they're smaller, they're also fainter, hence 'under-luminous' compared to normal red giants."Only seven such under-luminous stars were found, and the authors suspect many more are hiding in the sample.These unusual data points could not be explained by simple expectations from stellar evolution. This led the researchers to conclude that another mechanism must be at work, forcing these stars to undergo dramatic weight loss: theft of mass by nearby stars. —IANS

An Australian team of astronomers have found a slimmer type of red giant star for the first time. These stars have undergone dramatic weight loss, possibly due to the presence of a greedy neighbour.

Astronomers Find First-Ever Slimmer Type Of Red Giant Stars

Dehradun (The Hawk): The Governor of Uttarakhand, Lt. General Gurmit Singh (Retd.) highlighted the need for discussing future possibilities of the 104 cm Sampurnanand Telescope (ST), a world-class telescope located near Nainital, at a workshop organised to commemorate the completion of 50 years of successful operations of the telescope.
Mr Singh felicitated former astronomers, research scholars, and staff members who contributed to the operation of this telescope and expressed hope that the contributions from the scientists and the technological capabilities will aid the progress of our country shaping the pathway for a developed nation in future, at the workshop organised by the Aryabhatta Research Institute of Observational Sciences (ARIES), an autonomous institute of the Department of Science and Technology (DST). “Question is the mother of wisdom,” he added, encouraging young scientists.
The 3-day workshop on ‘Role of meter class telescopes in modern-day astronomy’ was conducted during 17-19 October as part of Azadi Ka Amrit Mahotsav celebrations at ARIES. About 150 participants from various institutes and universities in different parts of the country, including many alumni and present ARIES members, attended the workshop. The deliberations focussed on astronomy with moderate-size optical telescopes with science sessions such as ‘Impact of ST in Growth of Astronomy in Early Days’, ‘Star Formation and Star Clusters’, ‘Stellar Polarimetry’, ‘Stellar Variability’, ‘High Energy Transients’, ‘Galaxies and Active Galactic Nuclei’ and ‘Engineering Upgradations’. A panel discussion on ‘Future Instrumentations’ was also organised on the future science capabilities of the telescope.
“Astronomers of four generations discussed the utilisation of this unique facility. How the telescope can be utilised optimally in the future for best science has been the focus of the panel discussion,” said Prof. Dipankar Banerjee, Director, ARIES.
Several former scientists, who had used 104cm ST for observations during the last 50 years, shared their experiences as well as the research impact of the telescope in the field of astronomy. On this occasion, a short documentary film presenting the 50-year-long journey of the telescope was released. A photobook presenting major science highlights and the history of the telescope was also unveiled by the former and present directors of ARIES, and senior astronomers of the country. The participants also visited the 104cm Sampurnanand Telescope facility and reminisced about the time they spent with this telescope.
The telescope at Manora Peak was established in 1972 when ARIES was known as the UP State Observatory (UPSO). It has been extensively used for optical observations of comets, occultation by planets and asteroids, star-forming regions and star clusters, variable stars, transients, active galactic nuclei, etc. Some of the breakthrough science results contributed by the telescope include the discovery of new rings around Saturn and the rings of Uranus. The instrumentation and science capabilities of ST have paved the way for setting up National and International facilities by ARIES, such as the 3.6m DOT and the 4 meter International Liquid Mirror Telescope at Devasthal.

The Governor of Uttarakhand, Lt. General Gurmit Singh (Retd.) highlighted the need for discussing future possibilities of the 104 cm Sampurnanand Telescope (ST), a world-class telescope located near Nainital, at a workshop organised to commemorate the completion of 50 years of successful operations of the telescope.

U'khand Guv Felicitates Astronomers, Encourages Young Scientists At Commemoration Of 50 Years Of Telescope

Washington: Twilight observations have enabled astronomers to spot three near-Earth asteroids (NEA) hiding in the glare of the Sun. These NEAs are part of an elusive population that lurks inside the orbits of Earth and Venus. One of the asteroids is the largest object that is potentially hazardous to Earth to be discovered in the last eight years.
An international team using the Dark Energy Camera (DECam) mounted on the Victor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory in Chile, a Program of NSF's NOIRLab, has discovered three new near-Earth asteroids (NEAs) hiding in the inner Solar System, the region interior to the orbits of Earth and Venus. This is a notoriously challenging region for observations because asteroid hunters have to contend with the glare of the Sun.
By taking advantage of the brief yet favorable observing conditions during twilight, however, the astronomers found an elusive trio of NEAs. One is a 1.5-kilometer-wide asteroid called 2022 AP7, which has an orbit that may someday place it in Earth's path. The other asteroids, called 2021 LJ4 and 2021 PH27, have orbits that safely remain completely interior to Earth's orbit. Also of special interest to astronomers and astrophysicists, 2021 PH27 is the closest known asteroid to the Sun. As such, it has the largest general-relativity effects [1] of any object in our Solar System and during its orbit its surface gets hot enough to melt lead.
"Our twilight survey is scouring the area within the orbits of Earth and Venus for asteroids," said Scott S. Sheppard, an astronomer at the Earth and Planets Laboratory of the Carnegie Institution for Science and the lead author of the paper describing this work. "So far we have found two large near-Earth asteroids that are about 1 kilometer across, a size that we call planet killers."
"There are likely only a few NEAs with similar sizes left to find, and these large undiscovered asteroids likely have orbits that keep them interior to the orbits of Earth and Venus most of the time," said Sheppard. "Only about 25 asteroids with orbits completely within Earth's orbit have been discovered to date because of the difficulty of observing near the glare of the Sun."
Finding asteroids in the inner Solar System is a daunting observational challenge. Astronomers have only two brief 10-minute windows each night to survey this area and have to contend with a bright background sky resulting from the Sun's glare. Additionally, such observations are very near to the horizon, meaning that astronomers have to observe through a thick layer of Earth's atmosphere, which can blur and distort their observations. [2]
Discovering these three new asteroids despite these challenges was possible thanks to the unique observing capabilities of DECam. The state-of-the-art instrument is one of the highest-performance, wide-field CCD imagers in the world, giving astronomers the ability to capture large areas of sky with great sensitivity. Astronomers refer to observations as 'deep' if they capture faint objects. When hunting for asteroids inside Earth's orbit, the capability to capture both deep and wide-field observations is indispensable. DECam was funded by the US Department of Energy (DOE) and was built and tested at DOE's Fermilab. "Large areas of sky are required because the inner asteroids are rare, and deep images are needed because asteroids are faint and you are fighting the bright twilight sky near the Sun as well as the distorting effect of Earth's atmosphere," said Sheppard. "DECam can cover large areas of sky to depths not achievable on smaller telescopes, allowing us to go deeper, cover more sky, and probe the inner Solar System in ways never done before."
As well as detecting asteroids that could potentially pose a threat to Earth, this research is an important step toward understanding the distribution of small bodies in our Solar System. Asteroids that are further from the Sun than Earth are easiest to detect. Because of that these more-distant asteroids tend to dominate current theoretical models of the asteroid population. [3]
Detecting these objects also allows astronomers to understand how asteroids are transported throughout the inner Solar System and how gravitational interactions and the heat of the Sun can contribute to their fragmentation.
"Our DECam survey is one of the largest and most sensitive searches ever performed for objects within Earth's orbit and near to Venus's orbit," said Sheppard. "This is a unique chance to understand what types of objects are lurking in the inner Solar System."
"After ten years of remarkable service, DECam continues to yield important scientific discoveries while at the same time contributing to planetary defense, a crucial service that benefits all humanity," said Chris Davis, NSF Program Director for NOIRLab. DECam was originally built to carry out the Dark Energy Survey, which was conducted by the DOE and the US National Science Foundation between 2013 and 2019. —ANI

Twilight observations have enabled astronomers to spot three near-Earth asteroids (NEA) hiding in the glare of the Sun. These NEAs are part of an elusive population that lurks inside the orbits of Earth and Venus. 

Astronomers Spot Largest Potentially Hazardous Asteroid Detected In Eight Years

Washington: An international team of astronomers have turned a new technique onto a group of galaxies and the faint light between them known as 'intra-group light' to characterise the stars that dwell there.
Lead author of the study published in MNRAS, Dr Cristina Martinez-Lombilla from the School of Physics at UNSW Science, said "We know almost nothing about intra-group light.
"The brightest parts of the intra-group light are ~50 times fainter than the darkest night sky on Earth. It is extremely hard to detect, even with the largest telescopes on Earth -- or in space."
Using their sensitive technique, which eliminates light from all objects except that from the intra-group light, the researchers not only detected the intra-group light but were able to study and tell the story of the stars that populate it.
"We analysed the properties of the intra-group stars -- those stray stars between the galaxy groups. We looked at the age and abundance of the elements that composed them and then we compared those features with the stars still belonging to galaxy groups," Dr Martinez-Lombilla said.
"We found that the intra-group light is younger and less metal-rich than the surrounding galaxies."
Not only were the orphan stars in the intra-group light 'anachronistic' but they appeared to be of a different origin to their closest neighbours. The researchers found the character of the intra-group stars appeared similar to the nebulous 'tail' of a further away galaxy.
The combination of these clues allowed the researchers to rebuild the history -- the story -- of the intra-group light and how its stars came to be gathered in their own stellar orphanage.
"We think these individual stars were at some points stripped from their home galaxies and now they float freely, following the gravity of the group," said Dr Martinez-Lombilla. "The stripping, called tidal stripping, is caused by the passage of massive satellite galaxies -- similar to the Milky Way -- that pull stars in their wake."
This is the first time the intra-group light of these galaxies has been observed.
"Unveiling the quantity and origin of the intra-group light provides a fossil record of all the interactions a group of galaxies has undergone and provides a holistic view of the system's interaction history," Dr Martinez-Lombilla said.
"Also, these events occurred a long time ago. The galaxies [we're looking at] are so far away, that we're observing them as they were 2.5 billion years ago. That is how long it takes for their light to reach us."
By observing events from a long time ago, in galaxies so far away, the researchers are contributing vital datapoints to the slow-burning evolution of cosmic events.
The researchers pioneered a unique technique to achieve this penetrating view.
"We have developed a tailored image treatment procedure that allows us to analyse the faintest structures in the Universe," said Dr Martinez-Lombilla.
"It follows the standard steps for the study of faint structures in astronomical images -- which implies 2D modelling and the removal of all light except that coming from the intra-group light. This includes all the bright stars in the images, the galaxies obscuring the intra-group light and a subtraction of the continuum emission from the sky.
"What makes our technique different is that it is fully Python-based so it is very modular and easily applicable to different sets of data from different telescopes rather than being just useful for these images.
"The most important outcome is that when studying very faint structures around galaxies, every step in the process counts and every undesirable light should be accounted for and removed. Otherwise, your measurements will be wrong.
The techniques presented in this study are a pilot, encouraging future analyses of intra-group light, Dr Martinez-Lombilla said.
"Our main long-term goal is to extend these results to a large sample of group of galaxies. Then we can look at statistics and find out the typical properties regarding the formation and evolution of the intra-group light and these extremely common systems of groups of galaxies.
"This is key work for preparing the next generation of deep all-sky surveys such as those to be performed with the Euclid space telescope and the LSST with the Vera C. Rubin Observatory." —ANI

 An international team of astronomers have turned a new technique onto a group of galaxies and the faint light between them known as 'intra-group light' to characterise the stars that dwell there.

Astronomers Observe Intra-Group Light, An Elusive Glow Between Distant Galaxies

Beijing: For the first time, astronomers have detected an image of a powerful jet exploding from a black hole. The observations of the black hole at the centre of the galaxy Messier 87 (M87) could help reveal how black holes can launch such energetic jets -- among the brightest objects in the universe. "We know that jets are ejected from the region surrounding black holes, but we still do not fully understand how this actually happens," said Ru-Sen Lu from the Shanghai Astronomical Observatory in China. "To study this directly we need to observe the origin of the jet as close as possible to the black hole," Lu said. Most galaxies harbour a supermassive black hole at their centre. While black holes are known for engulfing matter in their immediate vicinity, they can also launch powerful jets of matter that extend beyond the galaxies that they live in. Understanding how black holes create such enormous jets has been a long standing problem in astronomy. The new image published in the journal Nature shows precisely for the first time: how the base of a jet connects with the matter swirling around a supermassive black hole. The target is the galaxy M87, located 55 million light-years away, and home to a black hole 6.5 billion times more massive than the Sun. Previous observations had managed to separately image the region close to the black hole and the jet, but this is the first time both features have been observed together. "This new image completes the picture by showing the region around the black hole and the jet at the same time," said Jae-Young Kim from the Kyungpook National University in South Korea and the Max Planck Institute for Radio Astronomy in Germany. The image was obtained in 2018 with the Global Millimetre VLBI Array (GMVA), the Atacama Large Millimetre/submillimetre Array (ALMA), and the Greenland Telescope (GLT), forming a network of radio-telescopes around the globe working together as a virtual Earth-sized telescope. —IANS

For the first time, astronomers have detected an image of a powerful jet exploding from a black hole.

Astronomers Detect First Direct Image Of Black Hole Expelling A Powerful Jet

Washington: A team of astronomers have discovered an Earth-size exoplanet, or world beyond our solar system, that may be carpeted with volcanoes and is about 90 light-years away.
Called LP 791-18 d, the planet could undergo volcanic outbursts as often as Jupiter's moon Io, the most volcanically active body in our solar system.
The exoplanet was found using data from NASA's TESS (Transiting Exoplanet Survey Satellite) and retired Spitzer Space Telescope, as well as a suite of ground-based observatories.
The findings have been detailed in the scientific journal Nature.
"LP 791-18 d is tidally locked, which means the same side constantly faces its star," said Bjorn Benneke, astronomy professor at Trottier Institute for Research on Exoplanets (iREx) based at the University of Montreal in Canada.
"The day side would probably be too hot for liquid water to exist on the surface. But the amount of volcanic activity we suspect occurs all over the planet could sustain an atmosphere, which may allow water to condense on the night side," he added.
LP 791-18 d orbits a small red dwarf star about 90 light years away in the southern constellation Crater. The team estimates it's only slightly larger and more massive than Earth.
Astronomers already knew about two other worlds in the system before this discovery, called LP 791-18 b and c.
The inner planet b is about 20 per cent bigger than Earth. The outer planet c is about 2.5 times Earth's size and more than seven times its mass.
During each orbit, planets d and c pass very close to each other. Each close pass by the more massive planet c produces a gravitational tug on planet d, making its orbit somewhat elliptical.
On this elliptical path, planet d is slightly deformed every time it goes around the star.
These deformations can create enough internal friction to substantially heat the planet's interior and produce volcanic activity at its surface.
Jupiter and some of its moons affect Io in a similar way.
Planet d sits on the inner edge of the habitable zone, the traditional range of distances from a star where scientists hypothesise liquid water could exist on a planet's surface.
If the planet is as geologically active as the research team suspects, it could maintain an atmosphere. Temperatures could drop enough on the planet's night side for water to condense on the surface. Planet c has already been approved for observing time on the James Webb Space Telescope, and the team thinks planet d is also an exceptional candidate for atmospheric studies by the mission. —IANS

A team of astronomers have discovered an Earth-size exoplanet, or world beyond our solar system

Astronomers Discover Potentially Volcano-Covered Earth-Size Exoplanet

New Delhi (The Hawk): Scientists tracking the continuous evolution of the energy state of the core of a solar eruption that occurred on July 20, 2017, have found it strangely maintained a constant temperature as it erupted energetic and highly magnetised plasma from the solar corona into space. The finding can improve our understanding of how such eruptions can impact communication systems on Earth. Coronal Mass Ejections (CMEs) are large-scale eruptions of charged particles (plasma) and magnetic fields from the solar atmosphere into space. They can disrupt a range of ground- and space-based technologies and satellites on Earth. Thus, it is crucial to understand their evolution and propagation through interplanetary space. There is a wide range of plasma temperatures within CMEs, from cold chromospheric material (around 104 K) to hot plasma (around 107 K). When CMEs propagate, several processes can exchange energy (electrical, kinetic, potential, thermal, and so on.), thereby heating or cooling the plasma. To understand the underlying processes, it is important to study the evolution of thermodynamic properties (such as density, temperature, thermal pressure, etc.) of CMEs. This will help our ability to monitor space weather. In the past, scientists had studied the thermal evolution of CMEs in the solar corona. However, these earlier studies were limited to larger distances from the Sun (more than 1.5 times the radius of the Sun or RSun). It has been known that CME shows peculiar kinematics such as rapid expansion, and impulsive acceleration, in the heights below 3 times the radius of the Sun. However, the evolution of thermodynamic properties of CMEs is not yet well understood, primarily due to the lack of suitable observations in these heights. A team of scientists consisting of Dr. Vaibhav Pant and Prof. Dipankar Banerjee and researcher Ms. Jyoti Sheoran from Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital, an autonomous institute of the Department of Science &amp; Technology (DST), Govt. of India, and Dr. Ritesh Patel from Southwest Research Institute, Boulder, USA tracked the continuous evolution of the thermodynamic properties of the core of a solar eruption that occurred on July 20, 2017. In a study published in the journal Frontiers in Astronomy and Space Sciences journal, they estimated the temperature and density of this CME core and found that strangely the CME core maintains a constant temperature as it propagates from 1.05 to 1.35 Rsun despite the expected adiabatic cooling due to the expansion of the core. They used data from the ground-based instruments MLSO (Mauna Loa Solar Observatory) /K-Cor (K-cronagraph) and MLSO/CoMP (Coronal Multichannel Polarimeter) as well as data from the space-based SDO (Solar Dynamics Observatory) /AIA (Atmospheric Imaging Assembly) telescopes for the purpose and also established that the density of the CME core decreased by a factor of around 3.6 as it propagated outwards. The authors conclude that the expansion of this CME core behaves more like an isothermal than an adiabatic process (thermodynamic process in which there is no exchange of heat from the system to its surrounding). The Visible Emission Line Coronagraph (VELC) onboard Aditya-L1, India’s first solar mission will be launched soon and it will perform both spectroscopy and imaging of the CMEs in the inner corona. A similar kind of analysis using VELC data will provide new insights of the evolution of CME thermodynamic properties in the inner corona.

 Scientists tracking the continuous evolution of the energy state of the core of a solar eruption that occurred on July 20, 2017

Astronomers Spot A Surprising Solar Eruption That Maintains Constant Temperature

Washington: Astronomers have uncovered a link between Neptune’s disappearing clouds and the increasing activity of the Sun as it approaches its solar cycle, expected to occur in 2025.  The Sun is currently in an active phase of its 11-year solar weather cycle, known as Solar Cycle 25. The solar cycle is the period when the Sun’s magnetic field flips every 11 years as it becomes more tangled like a ball of yarn. This is evident in the increasing number of sunspots and increasing solar flare activity.  As the cycle progresses, the Sun’s tempestuous behaviour builds to a maximum, until the magnetic field breaks down and reverses polarity. Then the Sun settles back down to a minimum, only to start another cycle.  The link between Neptune and solar activity is surprising to planetary scientists because Neptune is the farthest major planet in the solar system. It receives sunlight with about 0.1 per cent of the intensity Earth receives.  Yet Neptune’s global cloudy weather seems to be driven by solar activity, and not the planet’s four seasons, which each last approximately 40 years.  The team led by University of California (UC) Berkeley discovered the connection between the solar cycle and Neptune’s cloudy weather pattern by looking at 2.5 cycles of cloud activity recorded over the 29-year span of Neptunian observations.   During this time, the planet’s reflectivity increased in 2002 then dimmed in 2007. Neptune became bright again in 2015, then darkened in 2020 to the lowest level ever observed, which is when most of the clouds went away.  At present, the cloud coverage seen on Neptune is extremely low, with the exception of some clouds hovering over the giant planet’s south pole, the team wrote in the paper published in the journal Icarus.  “I was surprised by how quickly clouds disappeared on Neptune,” said Imke de Pater, professor of astronomy at UC Berkeley.   “We essentially saw cloud activity drop within a few months,” she said.  “Even now, four years later, the most recent images we took this past June still show the clouds haven’t returned to their former levels,” said Erandi Chavez, a graduate student at the Center for Astrophysics | Harvard-Smithsonian (CfA) in Cambridge, Massachusetts, who led the study when she was an undergraduate astronomy student at UC Berkeley.  “This is extremely exciting and unexpected, especially since Neptune’s previous period of low cloud activity was not nearly as dramatic and prolonged.”   To monitor the evolution of Neptune’s appearance, Chavez and her team analysed Keck Observatory images taken from 2002 to 2022, the Hubble Space Telescope archival observations beginning in 1994, and data from the Lick Observatory in California from 2018 to 2019.  The images reveal an intriguing pattern between seasonal changes in Neptune’s cloud cover and the solar cycle.  When it’s stormy weather on the Sun, more intense ultraviolet (UV) radiation floods the solar system. The team found that two years after the solar cycle’s peak, an increasing number of clouds appear on Neptune. The team further found a positive correlation between the number of clouds and the ice giant’s brightness from the sunlight reflecting off it.  “These remarkable data give us the strongest evidence yet that Neptune’s cloud cover correlates with the Sun’s cycle,” said de Pater. “Our findings support the theory that the Sun’s UV rays, when strong enough, may be triggering a photochemical reaction that produces Neptune’s clouds.” —IANS

Astronomers have uncovered a link between Neptune’s disappearing clouds and the increasing activity of the Sun

Sun's activity is behind Neptune vanishing clouds

Washington: An Earth-like Planet Nine may be hiding in our solar system, behind Neptune, Japanese astronomers have found. The study, published in the Astronomical Journal, comes amidst ongoing debate on the existence of a so-called ‘Planet Nine’, after Pluto was declared a dwarf planet 2006. Researchers Sofia Lykawka from Kindai University in Osaka and Takashi Ito from the Japan National Astronomy Observatory found the presence of the Earth-like planet in the Kuiper Belt -- a donut-shaped ring that stretches just beyond Neptune's orbit. The Kuiper Belt is a massive ring composed of interstellar objects such as dwarf planets, asteroids, carbon masses and icy volatile elements like methane and ammonia. "We predict the existence of Earth-like planets," said the researchers. "It's possible that a body of a primordial planet can survive in the far Kuiper Belt as a KBP, as so many bodies existed early in the solar system." According to them, Planet Nine has a mass that is about 1.5 to 3 times that of Earth, and at a distance of 500 astronomical units from the Sun. The Kuiper Belt also contains millions of frozen objects, which are referred to as trans-Neptunian objects (TNOs) because they are outside Neptune. TNOs are believed to be remnants of the formation of the solar system and consist of mixtures of rock, amorphous carbon, and volatile ices such as water and methane. "We determined that an Earth-like planet located on a distant and inclined orbit can explain three fundamental properties of the distant Kuiper Belt: a prominent population of TNOs with orbits beyond Neptune's gravitational influence, a significant population of high-inclination objects, and the existence of some extreme objects with peculiar orbits," they said in the paper. "That's right, a prominent TNO population with orbits beyond Neptune's gravitational influence, a population of objects with significant high inclinations, and the presence of some extreme objects with peculiar orbits."  Speaking to Daily Mail, they said "the orbit of TNO can indicate the presence of planets that have not been found outside the solar system". Some of these objects have strange orbits' that suggest they are being gravitationally influenced by something larger nearby. —IANS

An Earth-like Planet Nine may be hiding in our solar system, behind Neptune, Japanese astronomers have found

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Astronomers Find Rapid, Unexpected Changes In Neptune's Temperatures

Sunil Aswal

Tag : Astronomers

Astronomers Find Rapid, Unexpected Changes In Neptune's Temperatures

Sunil Aswal

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