Researchers determine physical conditions of two exoplanets in Kepler36 system

first_img Explore further © 2016 Phys.org An artist’s conception shows Kepler-36c as it might look from the surface of neighboring Kepler-36b. Credits: Harvard-Smithsonian Center for Astrophysics/David Aguilar. Based on the available data from NASA’s Kepler exoplanet-hunting spacecraft, James Owen from the Institute for Advanced Study in Princeton and Timothy Mortom of the Princeton University were looking for information that would be helpful in determining initial physical conditions of both planets. They performed hydrodynamic calculations to obtain a detailed evaporation model constraining the possible “birth” composition of this system. The model shows direct connection between the system’s present-day observed properties and formation theories like present-day mass and radius as a function of core-mass, core composition, initial envelope-mass fraction, and initial cooling time.”We calculate the evolution of each planet independently, including evaporation and bolometric irradiation by the central star. As we evaluate this evolution on grids of initial physical conditions, we are able to use the inferred posterior distribution of the planets’ present-day properties calculated from the transit timing variations to constrain these initial conditions,” the researchers wrote in the paper.They found out that Kepler-36b has an evaporatively stripped core, while Kepler-36c has retained some of its initial envelope due to its higher core mass and that both exoworlds could have had a similar formation pathway. With the core-mass of about 4.4 Earth masses, the inner planet has an initial envelope-mass fraction of less than 10 percent. The outer planet’s envelope-mass fraction is estimated to be between 15 and 30 percent and its core mass is approximately 7.3 times the mass of the Earth.Overall, the model used by Owen and Mortom allows scientists to uncover important information about exoplanet structure shortly after formation. “A well described birth envelope-mass, core-mass relation along with any intrinsic scatter would provide a strong constraint for any planet formation model,” the paper reads.The researchers also discovered that Kepler-36c had a long initial cooling-time, lasting more than 30 million years. This finding points to a dramatic cooling process that took place early in the planet’s life. According to the scientists, such a lengthy process could be also caused by inefficient heat transport, possibly occurring after giant impacts.What puzzles the researchers is that although the two planets are very close to each other, there is a significant disparity in densities of these celestial bodies. They suspect that some process must have occurred in order to produce such a system after six billion years of evolution.The findings suggest that planets with larger core masses accrete a larger initial envelope, which is not unexpected theoretically. The scientists hope that with a reasonable sample of well constrained planet masses and radii, it would able to infer the birth envelope-mass/core-mass relation and to provide crucial insights into the evolution process of extrasolar planets.”The observations necessary to begin this exploration has already been provided by Kepler, and the upcoming TESS (Transiting Exoplanet Survey Satellite) mission promises to deliver an even larger, possibly age-dependent sample,” they concluded. More information: The initial physical conditions of Kepler-36 b & c, arXiv:1511.07385 [astro-ph.EP] arxiv.org/abs/1511.07385AbstractThe Kepler planetary system consists of two exoplanets at similar separations (0.115 & 0.128 AU), which have dramatically different densities. The inner planet has a density consistent with an Earth-like composition, while the outer planet is extremely low-density, such that it must contain a voluminous H/He envelope. Such a density difference would pose a problem for any formation mechanism if their current densities were representative of their composition at formation. However, both planets are at close enough separations to have undergone significant evaporation in the past. We constrain the core-mass, core composition, initial envelope-mass, and initial cooling-time of each planet using evaporation models conditioned on their present-day masses and radii, as inferred from Kepler photometry and transit timing analysis. The inner planet is consistent with being an evaporatively stripped core, while the outer planet has retained some of its initial envelope due to its higher core-mass. Therefore, both planets could have had a similar formation pathway, with the inner planet having an initial envelope-mass fraction of ≲10% and core-mass of ∼4.4 M⊕, while the outer had an initial envelope-mass fraction of order 15-30% and core-mass ∼7.3 M⊕. Finally, our results indicate that the outer planet had a long (≳30 Myr) initial cooling-time, much longer than would naively be predicted from simple timescale arguments. The long initial cooling-time could be evidence for a dramatic early cooling episode such as the recently proposed “boil-off” process. Measuring the mass of a Mars-size exoplanet Citation: Researchers determine physical conditions of two exoplanets in Kepler-36 system (2016, February 11) retrieved 18 August 2019 from https://phys.org/news/2016-02-physical-conditions-exoplanets-kepler-.html (Phys.org)—Located about 1,530 light years from the Earth in the constellation of Cygnus, Kepler-36 is a sun-like star orbited by two known alien worlds. The inner planet, designated Kepler-36b is a so-called “super-Earth,” as it is larger than our home planet but smaller than Neptune; the larger Kepler-36c, resembling the solar system’s outermost planet, is described as a “mini-Neptune.” What is unusual about this planetary system is that these two exoworlds have very close orbits, separated only by 0.013 astronomical units (AU)—five times the Earth-moon distance. In a new research paper published online on Feb. 9, Princeton scientists are trying to determine physical conditions and understand the evolution process of this curious, distant system. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

Science Says There Is Such a Thing as Too Little Procrastination and

first_img… There are a million and one articles out there about how to stop procrastinating. This column isn’t one of them. This column is here to tell you that this is such a thing as procrastinating too little.  If that seems like utter nonsense to you, fear not. It was complete gibberish to me too when I first came across the science of something called “precrastination,” but the research on the subject turns out to be pretty clear. We can make ourselves less productive by rushing to do tasks, just as much as by putting them off. Here’s how. center_img You probably shouldn’t have, according to a now classic 2014 experiment by Pennsylvania State University psychologist David Rosenbaum. For his study Rosenbaum asked students to pick up a bucket and carry it down a hallway, specifically asking them to do the task in the easiest way possible. That sounds simple enough, but here’s the twist: the students could choose to either grab one bucket that was halfway down the hallway or another that was just a short distance from the end.  Read the whole story: Inc.last_img read more

Delhi put on your party shoes

first_imgComing to the Capital this weekend is All Starr Jamm, organised by Bestseller India along with contemporary artists like Rabbi Shergill, Shantanu Pandit, Talia Bentson and Samara Chopra to enthrall the city.‘After the grand success in Mumbai and Bangalore since its inception in May, 2012, Delhi edition will be a platform to provide young voices of the country and artists to carry out the best in them that links them up with our brand’s young and voguish target audience, said Vineet Gautam- Head, BESTSELLER India. Also Read – ‘Playing Jojo was emotionally exhausting’‘The idea behind the All Star Jamm is to connect with the youth of the country who are the driving force of the progressive cultural wave in India,’ he added.Come witness the night of fashion and music coming together to fuse both creativity and glamour and get enticed. We think this one is going to be your perfect get away this weekend.Where: DLF Place Mall, Saket When: 13 DecemberTimings: 9 pm onwardslast_img read more

Pakistani family sentenced to death over honour killing

first_imgFour relatives of a pregnant woman who bludgeoned her to death outside one of Pakistan’s top courts were sentenced to death on Wednesday for the crime, their defence lawyer said. The 25-year-old’s family attacked her because they objected to her marriage. Farzana Iqbal’s murder in May this year briefly focused attention on Pakistan’s epidemic of violence against women. Her father, brother, cousin, and another relative were all sentenced to death and a $1,000 fine, said defence lawyer Mansoor Afridi. Another cousin was sentenced to 10 years in prison and also fined $1,000.last_img

Man arrested for sexually assaulting minor in Bally

first_imgKolkata: A middle-aged man was arrested on charges of sexually harassing a minor at Bally in Howrah on Thursday late night.Police said it was on Thursday night when the man promised the girl of giving a toffee and took her to a deserted place. The man sexually harassed the girl. The victim somehow managed to flee the place and returned to her house in a traumatised state.She broke into tears when her parents enquired if anything had gone wrong. Later she revealed it to her parents, who lodged a complaint with the police. Also Read – Heavy rain hits traffic, flightsLocals also started agitating against the incident and police reached the spot soon after receiving the complaint and brought the situation under control. They demanded immediate arrest of the man.Locals did not allow the man to escape from the area and handed him over to the police when they reached the spot. Police have also visited the deserted place where the arrested man had taken the victim.Police initiated a probe in this connection. They have taken the statement of the victim’s parents. Police have also spoken to the locals to know whether they was anything suspicious in the behaviour of the arrested person. They are taking necessary steps to ensure that such incidents donot take place in the area again.last_img read more

Pick perfumes to suit your personality

first_imgFinding the perfect fragrance can be a tough nut to crack! Choose a perfume from family of six fragrance groups —  fresh, floral, oriental, woods, fougère and chypre, that blends with your personality, say experts. Keep the following points in mind while choosing a perfume: Scents you like: Take a stock of the fragrances you like. It can be the smell of a particular flower or fruit or maybe of rain and wet earth or sandalwood. Also Read – ‘Playing Jojo was emotionally exhausting’ Once you decide the smell you like the most, it will be easier for you to find the perfume with similar notes. Person you are buying the perfume for: Buy a perfume according to the personality of the person you are buying it for as perfumes and personality traits go hand-in-hand.For your mother, pick up something with notes of vanilla and white musk which will echo her confidence making her smell remarkably radiant.  Also Read – Leslie doing new comedy special with NetflixGift a perfume with notes of rose and blackcurrant to that flirty friend of yours that bring out her playfulness with elegance and grace.Choose perfumes with notes of cardamom, lavender and cinnamon for your rockstar father who is an icon to you.Shower your love on a free spirited vivacious man with fragrances that have notes of lemon, cedar, oak moss and mandarin. Best for your skin type: Always spray it on your skin to see if the fragrance works well for you. Also consider the type of skin you have before wearing a perfume. On dry skin, the fragrance will dissipate faster. For a long lasting effect, remember to moisturise your skin as the fragrance will blend in with the moisturised skin ensuring long lasting fragrance. Wearing the fragrance: Perfumes tend to react with fluctuating body temperature throughout the day and emit scent accordingly. To maximise the smell of your perfume, apply it on your pulse points. Wear the perfume on wrist, inside your elbows, the nape of your neck, on your cleavage and even behind the knees. A light mist of fragrance through the hair can also be applied for a long lasting effect.last_img read more

A tribute to the Mahanayak

first_imgUttam Kumar, a popular matinee idol, actor extraordinaire and the first megastar of Bengali film industry has left an indelible mark in the history of the Bengali film industry, especially the period which is regarded by critics as its ‘golden age’. To pay tribute to the legendary actor, fondly called Mahanayak, or the Great Hero, the Government of West Bengal organized a retrospective of his films at Muktadhara Auditorium on Friday.The festival was inaugurated by Atanu Purkayastha, Additional Chief Secretary, Government of West Bengal and RD Meena, Principal Resident Commissioner, Government of West Bengal. Also Read – ‘Playing Jojo was emotionally exhausting’The two films screened at the retrospective were Jhinder Bondi (1961), a classic tale of royalty, power and greed directed by Dadasaheb Phalke Awardee filmmaker Tapan Sinha and Nayak (1966), one of the most powerful works of movie maestro Satyajit Ray which deals with the life of a film star, delving into his innermost secrets and bringing out the man behind the façade of a matinee idol.The West Bengal Information and Cultural Centre, under the Office of the Resident Commissioner, West Bengal, regularly holds special screening of critically acclaimed movies for the connoisseurs of the national capital.last_img read more

Delhi most expensive Indian city for expatriates Survey

first_imgNew Delhi is India’s most expensive city for expatriates but was ranked in the 174th place in the global list, according to findings of the latest ‘Cost of Living’ survey by ECA International.Despite prices rising at a much slower pace than a year ago, Indian locations have climbed up the list of most expensive locations for expatriates. New Delhi has moved up 6 spots in the regional ranking to 41st place. Globally, it is now 174th most expensive location for expatriates, up from 208th last year. Also Read – Man arrested for making hoax call at IGI airportMumbai, 48th regionally, ranks 197th in the global list up from 225th place. “Over the year we’ve seen the price of items in ECA’s shopping basket for India rise more slowly than the year before, particularly food and motoring,” ECA International Regional Director Asia Lee Quane said, adding that “however, during the same period the rupee strengthened against a number of other major currencies and this has pushed up costs for expatriates.” Other Indian cities in the list include Pune with a regional rank of 51 and global rank of 209, Chennai (regional rank 52, global rank 214), Bengaluru (regional rank 54, global rank 220), Kolkata (regional rank of 55, global rank 226) and Hyderabad (regional rank 56 and global rank 227). Also Read – Disqualified AAP MLA Kapil Mishra, women’s wing chief join BJPMeanwhile, Shanghai has become Asia Pacific’s most expensive location for expatriates for the first time. It was ranked 8th globally followed by Beijing (9th globally) and Seoul (10th globally). Globally, the South Sudan city of Juba is the world’s most expensive location for expatriates, followed by Luanda and Zurich.To ensure that an employee’s spending power is maintained when they are sent on international assignment, a cost of living allowance is often provided as part of the pay package.last_img read more

British national with satellite phone detained at airport

first_imgKolkata: A British national was detained by the Central Industrial Security Force at Kolkata Airport on Thursday for carrying a satellite phone.He was later handed over to the police. The officers at NSCBI Police Station seized the satellite phone.Around 3.30 pm on Thursday, the 33-year-old British national, Prior Mathew, was detained at the airport after the CISF personnel found a satellite phone in his handbag. It was found during the pre-embarkation security check through X-BIS machine in the Security Hold Area at the airport. Also Read – Rain batters Kolkata, cripples normal lifeSub-inspector Ved Prakash of CISF detected the satellite phone from Mathew’s handbag. He was supposed to travel from Kolkata to Delhi by an Air India flight. He was scheduled to take a connecting flight to Hong Kong from Delhi.According to police sources, the satellite phone was seized as its use is ban in India. He was allowed to go following discussions over the matter with the British Consulate in Kolkata.All documents related to the satellite phone have to be produced before the police. They are looking into the legal provisions in this connection and would further speak to Mathew to get details about the satellite phone that was found in his possession. It may be mentioned that the CISF personnel maintain strict vigil at the airport and have taken Mathew to the police immediately after the satellite phone was found.last_img read more

Hope Hindu fringe elements are checked Mehbooba

first_imgClaiming that Bihar election results have done a “great job” in answering communal elements, PDP President Mehbooba Mufti on Saturday hoped that “fringe elements” acting in the name of Hinduism will be checked, drawing comparison with elements of ISIS who misuse Islam.She also made it clear that the PDP-BJP alliance in the state was mainly aimed at taking the peace initiatives of former Prime Minister Atal Bihari Vajpayee in resolving the Kashmir issue to its logical conclusion.“In our country tolerance is the strength and if we don’t stop these so-called fringe elements… What is happening in Syria, Afghanistan, Iraq… because those are also fringe elements who are misusing the name of Islam.last_img