Experimental Astronomy最新文献

{"title":"Development of a very faint meteor detection system based on an EMCCD sensor and matched filter processing","authors":"P. Gural,&nbsp;T. Mills,&nbsp;M. Mazur,&nbsp;P. Brown","doi":"10.1007/s10686-021-09828-3","DOIUrl":"10.1007/s10686-021-09828-3","url":null,"abstract":"<div><p>The mass ranges of meteors, imaged by electro-optical (EO) cameras and backscatter radar receivers, for the most part do not overlap. Typical EO systems detect meteoroid masses down to 10^− 5 kg or roughly magnitude + 2 meteors when using moderate field of view optics, un-intensified optical components, and meteor entry velocities around 45 km/sec. This is near the high end of the mass range of typical meteor radar observations. Having the same mass meteor measured by different sensor wavelength bands would be a benefit in terms of calibrating mass estimations for both EO and radar. To that end, the University of Western Ontario (UWO) has acquired and deployed a very low light imaging system based on an electron-multiplying CCD camera technology. This embeds a very low noise, per pixel intensifier chip in a cooled camera setup with various options for frame rate, region of interest and binning. The EO system of optics and sensor was optimally configured to collect 32 frames per second in a square field of view 14.7 degrees on a side, achieving a single-frame stellar limiting magnitude of m_<i>G</i> = + 10.5. The system typically observes meteors of + 6.5. Given this hardware configuration, we successfully met the challenges associated with the development of robust image processing algorithms, resulting in a new end-to-end processing pipeline now in operation since 2017. A key development in this pipeline has been the first true application of matched filter processing to process the faintest meteors possible in the EMCCD system while also yielding high quality automated metric measurements of meteor focal plane positions. With pairs of EMCCD systems deployed at two sites, triangulation and high accuracy orbits are one of the many products being generated by this system. These measurements will be coupled to observations from the Canadian Meteor Orbit Radar (CMOR) used for meteor plasma characterization and the Canadian Automated Meteor Observatory (CAMO) high resolution mirror tracking system.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"53 3","pages":"1085 - 1126"},"PeriodicalIF":3.0,"publicationDate":"2022-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10686-021-09828-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4417595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A retrieval challenge exercise for the Ariel mission","authors":"Joanna K. Barstow,&nbsp;Quentin Changeat,&nbsp;Katy L. Chubb,&nbsp;Patricio E. Cubillos,&nbsp;Billy Edwards,&nbsp;Ryan J. MacDonald,&nbsp;Michiel Min,&nbsp;Ingo P. Waldmann","doi":"10.1007/s10686-021-09821-w","DOIUrl":"10.1007/s10686-021-09821-w","url":null,"abstract":"<div><p>The Ariel mission, due to launch in 2029, will obtain spectroscopic information for 1000 exoplanets, providing an unprecedented opportunity for comparative exoplanetology. Retrieval codes - parameteric atmospheric models coupled with an inversion algorithm - represent the tool of choice for interpreting Ariel data. Ensuring that reliable and consistent results can be produced by these tools is a critical preparatory step for the mission. Here, we present the results of a retrieval challenge. We use five different exoplanet retrieval codes to analyse the same synthetic datasets, and test a) the ability of each to recover the correct input solution and b) the consistency of the results. We find that generally there is very good agreement between the five codes, and in the majority of cases the correct solutions are recovered. This demonstrates the reproducibility of retrievals for transit spectra of exoplanets, even when codes are not previously benchmarked against each other.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"53 2","pages":"447 - 471"},"PeriodicalIF":3.0,"publicationDate":"2022-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10686-021-09821-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4382782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A fast response mission to rendezvous with an interstellar object","authors":"Darren Garber,&nbsp;Louis D. Friedman,&nbsp;Artur Davoyan,&nbsp;Slava G. Turyshev,&nbsp;Nahum Melamed,&nbsp;John McVey,&nbsp;Todd F. Sheerin","doi":"10.1007/s10686-022-09835-y","DOIUrl":"10.1007/s10686-022-09835-y","url":null,"abstract":"<div><p>A solar sail propelled small satellite mission concept to intercept and potentially rendezvous with newly discovered transient interstellar objects (ISOs) is described. The mission concept derives from the proposal for a technology demonstration mission for exiting the solar system at high velocity, eventually to reach the focal region of the solar gravitational lens. The ISO mission concept is to fly a solar sail toward a holding orbit around the Sun and when the ISO orbit is confirmed, target the sailcraft to reach an escape velocity of over 6 AU/year. This would permit rapid response to a new ISO discovery and an intercept within 10 AU from the Sun. Two new proven interplanetary technologies are utilized to enable such a mission: i) interplanetary smallsats, such as those demonstrated by the MarCO mission, and ii) solar sails, such as demonstrated by LightSail and IKAROS missions and developed for NEA Scout and Solar Cruiser missions. Current technology work suggests that already within this decade such a mission could fly and reach an ISO moving through the solar system. It might enable the first encounter with an ISO to allow for imaging and spectroscopy, measurements of size and mass, potentially giving a unique information about the object’s origin and composition. A similar approach may be used to allow for a sample return.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"53 3","pages":"945 - 960"},"PeriodicalIF":3.0,"publicationDate":"2022-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4160263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two-mirror aplanatic telescopes with a flat field","authors":"V. Yu. Terebizh","doi":"10.1007/s10686-022-09833-0","DOIUrl":"10.1007/s10686-022-09833-0","url":null,"abstract":"<div><p>A complete description is given of two-mirror telescopes with a flat medial focal surface, on which the images of stars are <i>circles of least confusion</i>. Particular attention is paid to aplanats, since their field of view is noticeably larger than that of classical systems. Two sets of appropriate solutions correspond to Schwarzschild and Gregorian telescopes. As a result, it becomes possible to use flat light detectors with wide-field two-mirror telescopes. New designs are of particular interest when as few reflective surfaces as possible are required, which is typical for space exploration and non-optical observations.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"53 3","pages":"1075 - 1083"},"PeriodicalIF":3.0,"publicationDate":"2022-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5145245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling unresolved stellar components from photometry","authors":"Sergio Messina,&nbsp;Berto Monard","doi":"10.1007/s10686-022-09834-z","DOIUrl":"10.1007/s10686-022-09834-z","url":null,"abstract":"<div><p>Space-born missions designed to search for exo-planets are providing us with high-precision photometric time series very well suited to measure the rotation period of solar- and lower-mass stars. Considering the large number of stars monitored during the mission life, the possibility to inspect each periodogram is out of question and, therefore, each method to search for rotation periods applied either individually or in combination is designed to automatically select the best rotation period estimate. In the case of unresolved binary stars it is possible to measure the rotation period of both components, when these are both variable and have comparable magnitude. On the other hand, the detection of two different rotation periods from the same photometric timeseries can represents a tool to unveil the binary nature of the star. In this paper, we present the case of the star TWA 23, a member of the young TWA association, as just one example of numerous cases. These may occur when the star is an unresolved binary and the variability of the secondary component is present in the time series. However, the frequency of the primary and dominant power peak in the periodogram, originating from the primary component, needs to be pre-whitened to allow the frequency of the secondary component to be detected. Considering the possible presence of undiscovered close binaries in the input catalogs of various ongoing or future missions aimed at exoplanet search, it becomes advisable to follow routinely this filtering approach to prevent to miss relevant information on the true binary nature of stars.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"53 3","pages":"1149 - 1163"},"PeriodicalIF":3.0,"publicationDate":"2022-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10686-022-09834-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5082200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ariel mission planning","authors":"J.C. Morales,&nbsp;N. Nakhjiri,&nbsp;J. Colomé,&nbsp;I. Ribas,&nbsp;E. García,&nbsp;D. Moreno,&nbsp;F. Vilardell","doi":"10.1007/s10686-021-09822-9","DOIUrl":"10.1007/s10686-021-09822-9","url":null,"abstract":"<div><p>Automatic scheduling techniques are becoming a crucial tool for the efficient planning of large astronomical surveys. A specific scheduling method is being designed and developed for the Atmospheric Remote-sensing Infrared Exoplanet Large-survey (<i>Ariel</i>) mission planning based on a hybrid meta-heuristic algorithm with global optimization capability to ensure obtaining satisfying results fulfilling all mission constraints. We used this method to simulate the <i>Ariel</i> mission plan, to assess the feasibility of its scientific goals, and to study the outcome of different science scenarios. We conclude that <i>Ariel</i> will be able to fulfill the scientific objectives, i.e. characterizing <span>(sim)</span>1000 exoplanet atmospheres, with a total exposure time representing about 75–80% of the mission lifetime. We demonstrate that it is possible to include phase curve observations for a sample of targets or to increase the number of studied exoplanets within the mission lifetime. Finally, around 12–15% of the time can still be used for non-time constrained observations.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"53 2","pages":"807 - 829"},"PeriodicalIF":3.0,"publicationDate":"2022-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10686-021-09822-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4863134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum gravity with THESEUS","authors":"L. Burderi,&nbsp;A. Sanna,&nbsp;T. Di Salvo,&nbsp;A. Riggio,&nbsp;R. Iaria,&nbsp;A. F. Gambino,&nbsp;A. Manca,&nbsp;A. Anitra,&nbsp;S. M. Mazzola,&nbsp;A. Marino","doi":"10.1007/s10686-021-09825-6","DOIUrl":"10.1007/s10686-021-09825-6","url":null,"abstract":"<div><p>In this paper we explore the possibility to search for a dispersion law for light propagation <i>in vacuo</i> with a sample of Gamma-Ray Bursts detected by the THESEUS satellite. Within Quantum Gravity theories, different models for space-time quantization predict relative discrepancies of the speed of photons w.r.t. the speed of light that (in a series expansion) depend on a given power of the ratio of the photon energy to the Planck energy. This ratio is as small as 10^− 23 for photons in the soft <i>γ</i> −ray band (100 keV). The dominant effect is determined by the first significant term of this expansion. If the first order in this expansion is relevant, these theories imply a Lorentz Invariance Violation (LIV hereafter) and are generally dubbed LIV-theories. Therefore, to detect this effect, light must propagate over enormous distances and the experiment must have extraordinary sensitivity. Gamma-Ray Bursts, occurring at cosmological distances, could be used to detect this tiny signature of space-time granularity. Once the photons of a Gamma-Ray Burst are emitted at a given (cosmological) distance, they arrive on the detector with relative delays that linearly depends on the energy differences and on the distance travelled, that, given a set of cosmological parameters, is a unique function of the redshift. The strong temporal variability of the Gamma-Ray Bursts light-curves allows, with different techniques (e.g. cross-correlations), to compute these delays by comparing light-curves of Gamma-Ray Bursts for which the redshift is known, in adjacent energy bands covering a sufficiently wide energy range. In this way, LIV-theories can be effectively constrained. THESEUS offers the opportunity to collect a homogeneous set of GRBs for which the redshift is known, with a signal to background ratio sufficient to compute delays through cross correlation techniques, and covering an energy band (from few keV to few MeV) wide enough to produce significant delays. In this article we explore the possibility to constrain LIV-theories with THESEUS by means of Monte Carlo simulations. In summary, within the nominal duration of 3 years, THESEUS could constrain (or detect) Quantum Gravity Lorentz Invariance Violation effects at al level of 17 times the Planck Length (1.6 × 10^− 33 cm); if the mission is extended up to 7 years, this constrain is improved down to a level of 11 times the Planck Length.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"52 3","pages":"439 - 452"},"PeriodicalIF":3.0,"publicationDate":"2022-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10686-021-09825-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4787516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the synergy between Ariel and ground-based high-resolution spectroscopy","authors":"Gloria Guilluy,&nbsp;Alessandro Sozzetti,&nbsp;Paolo Giacobbe,&nbsp;Aldo S. Bonomo,&nbsp;Giuseppina Micela","doi":"10.1007/s10686-021-09824-7","DOIUrl":"10.1007/s10686-021-09824-7","url":null,"abstract":"<div><p>Since the first discovery of an extra-solar planet around a main-sequence star, in 1995, the number of detected exoplanets has increased enormously. Over the past two decades, observational instruments (both onboard and on ground-based facilities) have revealed an astonishing diversity in planetary physical features (i. e. mass and radius), and orbital parameters (e.g. period, semi-major axis, inclination). Exoplanetary atmospheres provide direct clues to understand the origin of these differences through their observable spectral imprints. In the near future, upcoming ground and space-based telescopes will shift the focus of exoplanetary science from an era of “species discovery” to one of “atmospheric characterization”. In this context, the Atmospheric Remote-sensing Infrared Exoplanet Large (Ariel) survey, will play a key role. As it is designed to observe and characterize a large and diverse sample of exoplanets, Ariel will provide constraints on a wide gamut of atmospheric properties allowing us to extract much more information than has been possible so far (e.g. insights into the planetary formation and evolution processes). The low resolution spectra obtained with Ariel will probe layers different from those observed by ground-based high resolution spectroscopy, therefore the synergy between these two techniques offers a unique opportunity to understanding the physics of planetary atmospheres. In this paper, we set the basis for building up a framework to effectively utilise, at near-infrared wavelengths, high-resolution datasets (analyzed via the cross-correlation technique) with spectral retrieval analyses based on Ariel low-resolution spectroscopy. We show preliminary results, using a benchmark object, namely HD 209458 b, addressing the possibility of providing improved constraints on the temperature structure and molecular/atomic abundances.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"53 2","pages":"655 - 677"},"PeriodicalIF":3.0,"publicationDate":"2022-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10686-021-09824-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4605367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Astronomical big data processing using machine learning: A comprehensive review","authors":"Snigdha Sen,&nbsp;Sonali Agarwal,&nbsp;Pavan Chakraborty,&nbsp;Krishna Pratap Singh","doi":"10.1007/s10686-021-09827-4","DOIUrl":"10.1007/s10686-021-09827-4","url":null,"abstract":"<div><p>Astronomy, being one of the oldest observational sciences, has collected a lot of data over the ages. In recent times, it is experiencing a huge data surge due to advancements in telescopic technologies with automated digital outputs. The main driver behind this article is to present various relevant Machine Learning (ML) algorithms and big data frameworks or tools being applied and can be employed in large astronomical data-set analysis to assist astronomers in solving multiple vital intriguing problems. Throughout this survey, we attempt to review, evaluate and summarize diverse astronomical data sources, gain knowledge of structure, the complexity of the data, and challenges in the data processing. Additionally, we discuss ample technologies being developed to handle and process this voluminous data. We also look at numerous activities being carried out all over the world enriching this domain. While going through existing literature, we perceived a limited number of comprehensive studies reported so far analyzing astronomy data-sets from the viewpoint of parallel processing and machine learning collectively. This motivated us to pursue this extensive literature review task by outlining up-to-date contributions and opportunities available in this area. Besides, this article also discusses briefly a cloud-based machine learning approach to estimate the extra-galactic object redshifts considering photometric data as input features. As the intersection of big data, machine learning and astronomy is a quite new paradigm, this article will create a strong awareness among interested young scientists for future research and provide an appropriate insight on how these algorithms and tools are becoming inevitable to the astronomy community day by day.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"53 1","pages":"1 - 43"},"PeriodicalIF":3.0,"publicationDate":"2022-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4570243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulated observations of heavy elements with CUBES","authors":"H. Ernandes,&nbsp;B. Barbuy,&nbsp;B. Castilho,&nbsp;C. J. Evans,&nbsp;G. Cescutti","doi":"10.1007/s10686-021-09829-2","DOIUrl":"10.1007/s10686-021-09829-2","url":null,"abstract":"<div><p>We investigate the feasibility of robust abundances for selected neutron-capture elements (Ge, Bi, Hf, U) from near-UV spectroscopy with the CUBES instrument now in development for the Very Large Telescope. We use the CUBES end-to-end simulator to synthesise observations of the Ge I 3039 Å and Hf II 3400 and 3719 Å lines in a very metal-poor star, using the well-studied star CS 31082-001 as a template. From simulated 4 hr exposures, we recover estimated abundances to ± 0.1 dex for Ge for <i>U</i> ∼ 14.25 mag., and for Hf for <i>U</i> = 18 mag. These performances neatly highlight the powerful gain of CUBES for near-UV observations of targets that are two-to-three magnitudes fainter than the existing observations of CS 31082-001 (<i>U</i>= 12.5 mag.). We also investigate the weak Bi I 3025 Å and U II 3860 Ålines (for <i>U</i> ∼ 14.25 and 16 mag., respectively), finding that simulated 4 hr exposures should provide upper limits to these observationally challenging lines.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"55 1","pages":"149 - 163"},"PeriodicalIF":3.0,"publicationDate":"2022-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4570263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}