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  • richardmitnick 10:50 pm on July 30, 2021 Permalink | Reply
    Tags: "Astronomers study a hot Jupiter in unprecedented detail thanks to SPIRou!", , , Canada France Hawaii Telescope, , Hawaii, , , The exoplanet Tau Boötis b and its host star Tau Boötis,   

    From Canada France Hawaii Telescope, Mauna Kea Observatory, Hawaii, USA: “Astronomers study a hot Jupiter in unprecedented detail thanks to SPIRou!” 

    From Canada France Hawaii Telescope, Mauna Kea Observatory, Hawaii, USA


    Media Contact
    Mary Beth Laychak
    director of strategic communications, Canada-France-Hawai’i Telescope

    Scientific Contacts
    Stefan Pelletier (lead author)
    Ph.D. Candidate, Institute for Research on Exoplanets
    Université de Montréal, Montréal, Canada

    Björn Benneke (co-author)
    Professor, Institute for Research on Exoplanets
    Université de Montréal, Montréal, Canada

    Artistic rendition of the exoplanet Tau Boötis b and its host star, Tau Boötis.
    Image credits: Credit: L. Calçada. European Southern Observatory [Observatoire européen austral][Europäische Südsternwarte] (EU) (CL).

    An international team of astronomers has measured the most precise composition of the hot Jupiter Tau Boötis b’s atmosphere, providing us with a better understanding of giant planets. Using the SPIRou spectropolarimeter at the Canada-France-Hawaii Telescope in Hawaii, a team led by Stefan Pelletier, a PhD student at University of Montréal [Université de Montréal] (CA)‘s Institute for Research on Exoplanets (iREx), studied the atmosphere of the gas giant exoplanet Tau Boötis b, a scorching hot world that takes a mere three days to orbit its host star.

    Their detailed analysis, presented in a paper published today in The Astronomical Journal, shows that the atmosphere of the gaseous planet contains carbon monoxide, as expected, but surprisingly did not identify water, a molecule that was anticipated to be prevalent and should be easily detectable with SPIRou.

    Tau Boötis b is a planet that is 6.24 times more massive than Jupiter and 8 times closer to its parent star than Mercury to the Sun. Its host star, Tau Boötis, located 51 light years from Earth is 40% more massive than the sun and is one of the brightest known planet-bearing stars in the sky.

    Discovered in 1996, Tau Boötis b was one of the first exoplanets ever detected thanks to the radial velocity method. The radial velocity method studies the slight back-and-forth motion of a star generated by the gravitational tug of its planet.

    The planet’s atmospheric composition has been studied a handful of times before, but never with an instrument as powerful as SPIRou.

    “SPIRou’s high resolution and infrared wavelength range open a new window into the atmosphere of planets likeTau Boötis b,” says Dr. Luc Arnold, CFHT resident astronomer and SPIRou instrument scientist. “These are the kinds of observations that the instrument was designed for and we look forward to seeing what SPIRou uncovers next.”

    Studying hot Jupiters to better understand Jupiter and Saturn

    “Hot Jupiters like Tau Boötis b offer an unprecedented opportunity to probe giant planet formation”, said co-author Björn Benneke, astrophysics professor and Pelletier’s PhD supervisor at Université de Montréal. “The composition of the planet gives clues as to where and how this giant planet formed.”

    The key to revealing the formation location and mechanism of giant planets is imprinted in their atmospheric composition. The extreme temperature of hot Jupiters allows most molecules in their atmospheres to be in gaseous form and detectable with current instruments, enabling astronomers to precisely measure the content of their atmospheres.

    “In our Solar System, Jupiter and Saturn are much colder,” continues Benneke. “Some molecules such as water are frozen and hidden deep in their atmospheres. Thus, we have a very poor knowledge of their abundance. Studying exoplanets provides a better way to understand our own giant planets. For example, the low amount of water on Tau boötis b could mean that our own Jupiter is drier than we had previously thought.”

    SPIRou: a unique instrument

    Tau Boötis b is one of the first planets studied with SPIRou, which started observations at CFHT in 2018. SPIRou is an infrared spectropolarimeter which takes the light from a single object and breaks the light into its component infrared colors; colors our eyes are unable to detect. The observations allow astronomers to study the object’s characteristics– temperature, motion, and in the case of Tau Boötis b, the composition of the planet’s atmosphere.

    “This spectropolarimeter can analyze the planet’s thermal light — the light emitted by the planet itself — in an unprecedentedly large range of colours, and with a resolution that allows for the identification of many molecules at once: water, carbon monoxide, methane, etc.” explains iREx researcher Neil Cook, a co-author that is an expert on the SPIRou instrument.

    The team spent 20 hours observing the exoplanet with SPIRou between April 2019 and June 2020. This exquisite dataset allowed the researchers to make a detailed analysis of the molecular content of the hot Jupiter’s atmosphere.

    “We measured the abundance of all major molecules that contain either carbon or oxygen,” explains Pelletier. “Since they are the two most abundant elements in the universe, after hydrogen and helium, that gives us a very complete picture of the content of the atmosphere.”

    Tau Boötis b, like most planets, does not pass in front of its star as it orbits around it, from Earth’s point of view. Previously, the study of exoplanet atmospheres has mostly been limited to these “transiting” planets – those that cause periodic dips in the brightness of their star when they pass between us and the star, blocking some of the light.

    “It is the first time we got such precise measurements on the atmospheric composition of a non-transiting exoplanet. This work opens the dloor to studying in detail the atmospheres of a large number of exoplanets, even those that do not transit their star,” explains PhD student Caroline Piaulet, also a co-author of the study.

    Searching for water

    Assuming a similar composition as in the Solar System, models show that water vapour should be present in large quantities in the atmosphere of an exoplanet similar to Tau Boötis b. It should thus have been easy to detect with an instrument such as SPIRou.

    “We expected a strong detection of water, with maybe a little carbon monoxide,” explains Pelletier. “We were, however, surprised to find the opposite, carbon monoxide, but no water.”

    The team worked hard to make sure the results could not be attributed to problems with the instrument or the analysis of the data.

    “Once we’ve convinced ourselves the content of water was indeed much lower than expected on Tau Boötis b, we were able to start searching for formation mechanisms that could explain this,” says Pelletier.

    A composition similar to Jupiter

    The analysis of Pelletier and colleagues allowed them to conclude that Tau Boötis b’s atmospheric composition has roughly five times as much carbon as that found in the Sun, quantities similar to that measured for Jupiter.

    This may be a hint that hot Jupiters could form much further from their host star, at distances that are similar to the giant planets in our Solar System, and simply experienced a different evolution, which included a migration towards the star.

    “According to what we found for Tau Böotis b, it would seem that, at least composition-wise, hot Jupiters may not be so different from our own Solar System giant planets after all,” concludes Pelletier.

    In addition to Stefan Pelletier, Björn Benneke, Neil Cook and Caroline Piaulet, the team includes Institute for Research on Exoplanets [Institut de recherche sur les exoplanètes]University of Montréal [Université de Montréal] (CA) members Antoine Darveau-Bernier, Anne Boucher, Louis-Philippe Coulombe, Étienne Artigau, David Lafrenière, Simon Delisle, Romain Allart, René Doyon, Charles Cadieux and Thomas Vandal, all based at University of Montréal [Université de Montréal] (CA), and seven other co-authors from France, the United States, Portugal and Brazil.

    Funding was provided by the the Technologies for Exo-Planetary Science (TEPS) CREATE program, the Fonds de recherche du Québec – Nature et technologies (FRQNT), the Natural Sciences and Engineering Research Council of Canada (NSERC), the Trottier Family Foundation and the French National Research Agency (ANR).

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Canada France Hawaii Telescope Observatory (US) hosts a world-class, 3.6 meter optical/infrared telescope. The observatory is located atop the summit of Mauna Kea, a 4200 meter, dormant volcano located on the island of Hawaii, USA.

    The CFH Telescope became operational in 1979. The mission of CFHT is to provide for its user community a versatile and state-of-the-art astronomical observing facility which is well matched to the scientific goals of that community and which fully exploits the potential of the Mauna Kea site.

  • richardmitnick 7:54 pm on June 8, 2017 Permalink | Reply
    Tags: , , , Hawaii,   

    From temblor: “M=5.3 earthquake shakes Hawaii’s Big Island” 



    June 8, 2017
    David Jacobson

    Today’s M=5.3 earthquake on Hawaii’s Big Island occurred near Hawaii Volcanoes National Park. (Picture from: USGS)

    At just past 7 a.m. local time today, a M=5.3 earthquake shook the Big Island of Hawaii. According to the USGS, very strong shaking was felt close to the epicenter, while in the capital city of Hilo 44 km to the north, light shaking was recorded by seismometers. At 11 a.m. this morning, 8 a.m. in Hawaii, over 700 people had reported feeling the quake, which is unlikely to cause damage due to the moderate magnitude and the fact that the epicenter was not close to populated centers. The area in which today’s quake occurred is dominated by active volcanism in Hawaii Volcanoes National Park.

    This Temblor map shows the location of today’s M=5.3 earthquake on the Big Island of Hawaii. What is also evident from this figure is that the Big Island is highly seismically active. Some of these quakes are volcanic earthquakes, while others are more traditional quakes.

    While most people imagine spectacular lava flows and Kilauea when they think of the Big Island of Hawaii, it is also a seismically active area. The majority of these earthquakes are “volcanic earthquakes,” meaning they are associated with magma moving beneath the surface. These quakes are often too small to be felt, but are picked up by local seismometers.

    In addition to these “volcanic earthquakes,” more traditional earthquakes also occur around the Big Island. These are caused as the immense weight of the Big Island causes the entire island to subside. In turn, normal (extensional) faulting results. Based on the location and magnitude of today’s earthquake, one of these normal faults is the likely culprit.

    Even though today’s quake was only moderate in size and there have been no reports of damage, the Big Island can and has experienced large magnitude quakes. In both 1975 and 1868, there were M=7.2 and M=7.9 earthquakes in similar locations to today’s earthquake. Both of these events caused damage and triggered local tsunamis up to 15 m high. A tsunami inundation map for Hawaii is shown in the figure below. What this shows is that, it is not just volcanic eruptions that Hawaiians have to be wary of.

    This Temblor map shows faults, earthquakes, and a tsunami inundation map for the Big Island of Hawaii.

    Based on the Global Earthquake Activity Rate (GEAR) model, today’s M=5.3 earthquake should not be considered surprising. This model uses global strain rates and historical seismicity since 1977 to forecast the likely earthquake magnitude in your lifetime anywhere on earth. From the Temblor figure below, you can see that nearly the entire Big Island, is susceptible to experiencing a M=5.5+ earthquake in your lifetime.

    This Temblor map shows the Global Earthquake Activity Rate (GEAR) model for the Hawaiian Islands. This model uses global strain rates and seismicity since 1977 to forecast the likely earthquake magnitude in your lifetime anywhere on earth. What can be seen from this figure is that in the location of today’s M=5.3 earthquake, a M=5.5+ quake is likely. Therefore, today’s shock should not be considered a surprise.

    Hawaiian Volcano Observatory
    University of Hawaii

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    You can help many citizen scientists in detecting earthquakes and getting the data to emergency services people in affected area.
    QCN bloc

    Quake-Catcher Network

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

    After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

    The Quake-Catcher Network is a distributed computing network that links volunteer hosted computers into a real-time motion sensing network. QCN is one of many scientific computing projects that runs on the world-renowned distributed computing platform Berkeley Open Infrastructure for Network Computing (BOINC).


    BOINC WallPaper

    The volunteer computers monitor vibrational sensors called MEMS accelerometers, and digitally transmit “triggers” to QCN’s servers whenever strong new motions are observed. QCN’s servers sift through these signals, and determine which ones represent earthquakes, and which ones represent cultural noise (like doors slamming, or trucks driving by).

    There are two categories of sensors used by QCN: 1) internal mobile device sensors, and 2) external USB sensors.

    Mobile Devices: MEMS sensors are often included in laptops, games, cell phones, and other electronic devices for hardware protection, navigation, and game control. When these devices are still and connected to QCN, QCN software monitors the internal accelerometer for strong new shaking. Unfortunately, these devices are rarely secured to the floor, so they may bounce around when a large earthquake occurs. While this is less than ideal for characterizing the regional ground shaking, many such sensors can still provide useful information about earthquake locations and magnitudes.

    USB Sensors: MEMS sensors can be mounted to the floor and connected to a desktop computer via a USB cable. These sensors have several advantages over mobile device sensors. 1) By mounting them to the floor, they measure more reliable shaking than mobile devices. 2) These sensors typically have lower noise and better resolution of 3D motion. 3) Desktops are often left on and do not move. 4) The USB sensor is physically removed from the game, phone, or laptop, so human interaction with the device doesn’t reduce the sensors’ performance. 5) USB sensors can be aligned to North, so we know what direction the horizontal “X” and “Y” axes correspond to.

    If you are a science teacher at a K-12 school, please apply for a free USB sensor and accompanying QCN software. QCN has been able to purchase sensors to donate to schools in need. If you are interested in donating to the program or requesting a sensor, click here.

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

    Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

    Below, the QCN Quake Catcher Network map
    QCN Quake Catcher Network map

  • richardmitnick 10:15 am on May 29, 2017 Permalink | Reply
    Tags: , , , , , Citizen scientists in search of failed stars, , Hawaii, NASA Infrared Telescope facility Mauna Kea, ,   

    From astrobites: “Citizen scientists in search of failed stars” 

    Astrobites bloc


    May 29, 2017
    Ingrid Pelisoli

    Title: The First Brown Dwarf Discovered by the Backyard Worlds: Planet 9 Citizen Science Project
    Authors: Marc J. Kuchner, Jacqueline K. Faherty, Adam C. Schneider et al.
    First Author’s Institution: NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory

    Status: Accepted to ApJL [open access]

    Not everyone can be a star. Brown dwarfs, for example, have failed on their attempt.

    Artist’s concept of a Brown dwarf [not quite a] star. NASA/JPL-Caltech

    These objects have masses below the necessary amount to reach pressure and temperature high enough to burn hydrogen into helium in their cores and thus earn the classification “star”. It’s not very long since we’ve learned of their existence. They were proposed in the 1960s by Dr. Shiv S. Kumar, but the first one was only observed many years later, in 1988 – and we are not even sure it is in fact a brown dwarf! We’ve only reached a substantial number of known brown dwarfs with the advent of infrared sky surveys, such as the Two Micron All Sky Survey (2MASS) and the Wide-field Infrared Survey Explorer (WISE).

    Caltech 2MASS Telescopes, a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center (IPAC) at Caltech, at the Whipple Observatory on Mt. Hopkins south of Tucson, AZ, and at the Cerro Tololo Inter-American Observatory near La Serena, Chile.

    NASA/WISE Telescope

    Discovering and characterising cold brown dwarfs in the solar neighbourhood is one of the primary science goals for WISE. There are two ways of doing that: 1) identifying objects with the colours of cold brown dwarfs; 2) identifying objects with significant proper motion. Brown dwarfs are relatively faint objects, so they need to be nearby to be detected. We can detect the movement of such nearby targets against background stars, which are so distant that they appear to be fixed on the sky. This movement is called proper motion. As the signal-to-noise ratio is not very good for such faint objects, the second method is the preferred one. However, single exposure WISE images are not deep enough to find most brown dwarfs. This is where today’s paper enters. The authors have launched a citizen science project called “Backyard Worlds: Planet 9” to search for high proper motion objects, including brown dwarfs and possible planets orbiting beyond Pluto, in the WISE co-add images. Co-add images are simply a sum of the single exposures images taking into account corrections to possible shifts between them. This increases signal-to-noise ratio and helps to detect faint targets. On today’s paper, they report the first discovery of their project: a new brown dwarf in the solar neighbourhood, which was identified only six days after the project was launched!

    Citizen science: a promising approach

    The idea behind citizen science is to engage numerous volunteers to tackle research problems that would otherwise be impractical or even impossible to accomplish. The Zooniverse community hosts lots of such projects, in disciplines ranging from climate science to history. Citizen science projects have made some remarkable discoveries in astronomy, such as KIC 8462852 (aka “Tabby’s Star”, “Boyajian’s star” or “WTF star”).

    Tabby’s Star is mysteriously dimming again as reported by Fairborn Observatory in Arizona.
    (Photo : Unexplained/YouTube screenshot)

    In “Backyard Worlds: Planet 9”, volunteers are asked to examine short animations composed of difference images constructed from time-resolved WISE co-adds. The difference images are obtained subtracting the median of two subsequent images from the image to be analysed. This way, if an object does not significantly move, it will disappear from the analysed image with the subtraction, leaving only moving objects to be detected. The images are also divided into tiles small enough to be analysed on a laptop or cell phone screen. The classification task consists in viewing one animation, which is composed of four images, and identifying candidates for two types of moving objects: “movers” and “dipoles”. Movers are fast moving sources, that travel more than their apparent width over the course of WISE’s 4.5 year baseline. Dipoles are slower-moving sources that travel less than their apparent width, so that there will be a negative image right next to a positive image, since the subtraction of the object’s flux will only be partial. An online tutorial is provided to show how to identify such objects and distinguish them from artifacts such as partially subtracted stars or galaxies, and cosmic rays.

    The discovery: WISEA 1101+5400

    Figure 1: Two co-adds of WISE data separated by 5 years showing how WISEA 1101+5400 has moved. The region shown is 2.0” x 1.6” in size. [Figure 2 from the paper]

    Five users reported a dipole on a set of images, which can be seen here, the first report taking place only six days after the project was launched. The object, called WISEA 1101+5400, can be seen on Figure 1. This source would be undetectable in single exposure images, while in these co-adds it is visible and obviously moving. Follow-up spectra were obtained 9 using the SpeX spectrograph on the 3 m NASA Infrared Telescope Facility (IRTF).

    NASA Infrared Telescope facility Mauna Kea, Hawaii, USA

    The average spectrum is shown on Figure 2. Both the object’s colours and the obtained spectra are consistent with a field T dwarf, a type of brown dwarf.

    Figure 2: In black, the spectrum for WISEA 1101+5400. A field T5.5 brown dwarf, SDSS J0325+0425, is shown in red for comparison. Atomic and molecular opacity sources that define the T dwarf spectral class are indicated. [Figure 3 from the paper]

    Assuming WISEA 1101+5400 is the worst case scenario, i.e. about as faint an object as this survey is able to detect and with the minimum detectable proper motion, the authors estimate that “Backyard Worlds: Planet 9” has the potential to discover about a hundred new brown dwarfs. If WISEA 1101+5400 is not the worst case scenario, but objects even fainter or with lower proper motion can be found, this number could go up.

    Although the discovery of only one brown dwarf might not seem worthy of celebration, this discovery demonstrates the ability of citizen scientists to identify moving objects much fainter than the WISE single exposure limit. It is yet another proof that science could use the help of enthusiasts. So if you’re not doing anything now, why not take your pick at https://www.zooniverse.org/ and help a scientist?

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    What do we do?

    Astrobites is a daily astrophysical literature journal written by graduate students in astronomy. Our goal is to present one interesting paper per day in a brief format that is accessible to undergraduate students in the physical sciences who are interested in active research.
    Why read Astrobites?

    Reading a technical paper from an unfamiliar subfield is intimidating. It may not be obvious how the techniques used by the researchers really work or what role the new research plays in answering the bigger questions motivating that field, not to mention the obscure jargon! For most people, it takes years for scientific papers to become meaningful.
    Our goal is to solve this problem, one paper at a time. In 5 minutes a day reading Astrobites, you should not only learn about one interesting piece of current work, but also get a peek at the broader picture of research in a new area of astronomy.

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