This study analyzes total electron content(TEC)variations during two solar eclipse events that occurred on October 25,2022,and October 14,2023.The solar eclipse of October 25,2022,was a partial solar eclipse,while the...This study analyzes total electron content(TEC)variations during two solar eclipse events that occurred on October 25,2022,and October 14,2023.The solar eclipse of October 25,2022,was a partial solar eclipse,while the eclipse of October 14,2023,was an annular solar eclipse.For this study,the data of eight International GNSS Service(IGS)stations from different eclipse coverage zones are used to analyze TEC variations.It is found that the stations located in the maximum eclipse cover zone exhibited notable decreases in TEC values.The minimum variation of about 11.76%in TEC values is observed at the station situating in about 20 percent eclipse cover zone,while it varies from 22%to 38%at the stations falling in about 60 percent eclipse cover zone.The highest variation in TEC values of about 44%is found at the stations in about 80 percent eclipse cover zone.The time of occurrence of maximum depletion in TEC values at each station is in line with their longitudinal sequence.Atmospheric gravity waves(AGWs)are also observed by performing wavelet analysis on TEC data.The global TEC maps visualize and confirm observed TEC variations,providing spatial and temporal insights into the ionospheric response.This analysis highlights the influence of station location and eclipse coverage on the magnitude and spatial distribution of TEC variations.展开更多
The occasion of the longest totality of an eclipse in the 18 yr 11^1/3 d saros cycle leads to taking stock of the scientific value of ground-based eclipse observations in this space age. Though a number of space satel...The occasion of the longest totality of an eclipse in the 18 yr 11^1/3 d saros cycle leads to taking stock of the scientific value of ground-based eclipse observations in this space age. Though a number of space satellites from the U.S., Europe, Japan, and Russia study the Sun, scientists at eclipses can observe the solar chromosphere and corona at higher spatial resolution, at higher temporal resolution, and at higher spectral resolution than are possible aloft. Furthermore, eclipse expeditions can transport a wide variety of state-of-the-art equipment to the path of totality. Thus, for at least some years to come, solar eclipse observations will remain both scientifically valuable and cost-effective ways to study the outer solar atmosphere.展开更多
Mutual events between natural satellites include mutual occultation and mutual eclipse. Mutual eclipse is another kind of mutual occultation as viewed from the center of the Sun instead of the Earth. Two mutual eclips...Mutual events between natural satellites include mutual occultation and mutual eclipse. Mutual eclipse is another kind of mutual occultation as viewed from the center of the Sun instead of the Earth. Two mutual eclipses of J2 Europa by J1 Io （2009 Aug. 28 and Sept. 12） were observed at Yunnan Observatory during the PHEMU09 international campaign. We will calculate the astrometric data of these Galilean satellites by analyzing and fitting the light curves we obtained. The limb-darkening was considered during modeling the light intensity of eclipsed satellites in the penumbra zone, by taking the Lommel-Seeliger scattering law into account. Several dynamical quantifies, such as the relative coordinates of the eclipsing satellite from the eclipsed one △α cos δ and △δ, impact parameter and mid-time corresponding to the impact parameter and the deviations O - C of observed △α cos d and △δ relative to ephemerides, were obtained for each event respectively.展开更多
We describe and analyze observations of mutual events of Galilean satellites made at the Yunnan Observatory in February 2003 from CCD imaging for the first time in China. Astrometric positions were deduced from these ...We describe and analyze observations of mutual events of Galilean satellites made at the Yunnan Observatory in February 2003 from CCD imaging for the first time in China. Astrometric positions were deduced from these photometric observations by modelling the relative motion and the photometry of the involved satellites during each event.展开更多
Four candidates of eclipsing multiples, based on new extraneous eclipses found on Kepler binary light curves, are presented and studied. KIC 7622486 is a double eclipsing binary candidate with orbital periods of 2.279...Four candidates of eclipsing multiples, based on new extraneous eclipses found on Kepler binary light curves, are presented and studied. KIC 7622486 is a double eclipsing binary candidate with orbital periods of 2.2799960 d and 40.246503 d. The two binary systems do not eclipse each other in the line of sight, but there is mutual gravitational influence between them which leads to the small but definite eccentricity of 0.0035（0.0022） associated with the short 2.2799960 d period orbit. KIC 7668648 is a hierarchical quadruple system candidate, with two sets of solid 203 4- 5 d period extraneous eclipses and another independent set of extraneous eclipses. A clear and credible extraneous eclipse is found on the binary light curve of KIC 7670485 which makes it a triple system candidate. Two sets of extraneous eclipses with periods of about 390 d and 220 d are found on KIC 8938628 binary curves, which not only confirm the previous conclusion of the 388.5 4- 0.3 triple system, but also indicate new additional objects that make KIC 8938628 a hierarchical quadruple system candidate. The results from these four candidates will contribute to the field of eclipsing multiples.展开更多
Thales of Miletus （640？-546 BC） is famous for his prediction of the total solar eclipse in 585 BC. In this paper, the author demonstrate how Thales may have used the same principle for prediction of solar eclipses ...Thales of Miletus （640？-546 BC） is famous for his prediction of the total solar eclipse in 585 BC. In this paper, the author demonstrate how Thales may have used the same principle for prediction of solar eclipses as that used on the Antikythera Mechanism. At the SEAC conference in Alexandria in 2009, the author presented the paper ＂Ten solar eclipses show that the Antikythera Mechanism was constructed for use on Sicily.＂ The best defined series of exeligmos cycles started in 243 BC during the lifetime of Archimedes （287-212 BC） from Syracuse. The inscriptions on the Antikythera Mechanism were made in 100-150 BC and the last useful exeligmos started in 134 BC. The theory for the motion of the moon was from Hipparchus （ca 190-125 BC）. A more complete investigation of the solar eclipses on the Antikythera Mechanism reveals that the first month in the first saros cycle started with the first new moon after the winter solstice in 542 BC. Four solar eclipses 537-528 BC, from the first saros cycle, and three one exeligmos cycle later, 487-478 BC, are preserved and may have been recorded in Croton by Pythagoras （ca 575-495 BC） and his school.展开更多
In abundant old observational records of lunar eclipses in ancient China, some with timing of lunar eclipse phase are significant to the study of secular variation and fluctuation of the Earth’s rotation.Among the ov...In abundant old observational records of lunar eclipses in ancient China, some with timing of lunar eclipse phase are significant to the study of secular variation and fluctuation of the Earth’s rotation.Among the over 700 observational records for about 400 lunar eclipses,133 observational times of eclipse phases about展开更多
During the total solar eclipse of 2013 November 3, a fiber-based spectrometer captured the flash spectrum within the wavelength range of 5162–5325Å, with the field-of-view positioned approximately 0.04 R⊙above ...During the total solar eclipse of 2013 November 3, a fiber-based spectrometer captured the flash spectrum within the wavelength range of 5162–5325Å, with the field-of-view positioned approximately 0.04 R⊙above the east limb, near the second-contact point. This placement near the innermost corona, together with the nearby Baily's beads, enabled the detection of emission lines from the photosphere, lower chromosphere, and corona in the same spectral frame. The higher field-of-view made the coronal line Fe XIV 5303Åmore visible, while the reduced intensity of photospheric and lower chromospheric light, caused by terrestrial scattering, also influenced the observed spectrum. Meanwhile, we selected 18 flash emission lines to measure the ratio of the relative line height of the flash emission line to the relative line depth of the corresponding solar absorption line. This ratio serves as a diagnostic of the source function, minimizing opacity effects. Comparison of disk and flash spectra shows that this ratio increases for spectral lines at greater formation heights, being strongest for chromospheric lines(particularly Fe II), moderate for photospheric low-FIP lines, and weakest for photospheric neutral lines. This trend suggests a rising source function with formation height, potentially linked to increasing electron temperatures or influenced by factors observed in flash spectra near active regions as reported in earlier studies.展开更多
A group of Chinese astronomers detected a weird pulsar that keeps emitting radio beams in long,regular pauses.After years of follow-up observations and careful data analyses,they finally revealed this exotic pulsar in...A group of Chinese astronomers detected a weird pulsar that keeps emitting radio beams in long,regular pauses.After years of follow-up observations and careful data analyses,they finally revealed this exotic pulsar in Science on May 23 as a rare case:it turns out to be eclipsed by a companion,very likely a helium star,with a mass similar to the Sun and in an orbit smaller than the solar radius.展开更多
To improve the level of sports social management,to achieve standardized management,quick query,scientific statistics of sports social information,and to meet the needs of sports organizers,social platform managers,an...To improve the level of sports social management,to achieve standardized management,quick query,scientific statistics of sports social information,and to meet the needs of sports organizers,social platform managers,and other users,this paper introduces a sports social management system based on Spring Boot.The system uses Eclipse for Java Web development,selects MySQL 5.6 database as the background data storage solution,uses Java language to write code,and uses Tomcat server to build the running environment of applications.The system has the function of adding,deleting,changing and checking sports activities,supporting the input,query and statistical analysis of users’sports results,sports consumption and sports distance,and also allows to add,delete,modify and query the information of sports friends,aiming to provide users with a comprehensive and efficient sports social information management platform.展开更多
We present a comprehensive analysis of BI CVn,an eclipsing overcontact binary system.New BVR photometric observations,combined with available spectroscopic data,were analyzed simultaneously using the Wilson–Devinney ...We present a comprehensive analysis of BI CVn,an eclipsing overcontact binary system.New BVR photometric observations,combined with available spectroscopic data,were analyzed simultaneously using the Wilson–Devinney method to derive the orbital and physical parameters of the system.The resulting stellar parameters are M1=0.58±0.01M⊙,M2=1.42±0.02M⊙,R1=0.88±0.01R⊙,R2=1.31±0.01R⊙,with an orbital separation of a=2.80±0.01R⊙.Based on all available CCD times of minimum light,including both ground-based and T ESS observations,the(O-C)diagram of BI CVn was analyzed.T he orbital period exhibits a long-term decrease at a rate of-2.3239(±0.0001)×10-8 day yr-1,likely due to mass transfer from the more massive to the less massive component.Superimposed on this trend is a cyclic variation with a period of 56.84±0.08 yr,indicative of a light-travel time effect caused by a third body,whose estimated mass is 0.63±0.02M⊙.Using these derived parameters,we modeled the binary’s evolution through non-conservative processes with the Binary Star Evolution code.The evolutionary tracks of the components were examined in multiple parameter planes,leading to an estimated merger timescale of approximately 2.70 Gyr.展开更多
Using ground-based telescopes,the multi-color photometric observations of the contact binary EF Boo were obtained in 2020,2023,and 2024.Combining these with 7-sectors of light curves from TESS data,the variations of t...Using ground-based telescopes,the multi-color photometric observations of the contact binary EF Boo were obtained in 2020,2023,and 2024.Combining these with 7-sectors of light curves from TESS data,the variations of the O'Connell effect in continuous time and shapes of light curves over several years were identified.Three sets of typical light curves were analyzed to determine the photometric solutions via the Wilson-Devinney program.Considering the spectroscopic mass ratio of q=0.53,these photometric solutions suggest that EF Boo is a W-type W UMa contact binary with the averaged filling factor of f=22.26%,a small temperature difference,and a cool spot on the primary component.If the variations of the O'Connell effect are due to the magnetic activity of this cool spot,the longitudinal location varied from 50.4 to 302.7 over the time interval of 1434 days.Based on all CCD minimum times from ground-based telescope and TESS data,the O-C curve was also analyzed.A cyclic oscillation(A3=0.00575 days,T3=27.8 yr)superimposed on a secular increase(dP/dt=6.74×10^(-8)day yr^(-1))was discovered for the first time.The successive increase is possibly a result of mass transfer from the less massive star to the more massive one.The cyclic oscillations were possibly explained by the light-travel time effect via a third body or the magnetic activities.From the short cadence observations from TESS,we also calculated the value of the O'Connell effect and O-C value for each cycle and found no correlation between the O'Connell effect and O-C over nearly 30 days across different sectors.展开更多
基金the Global GNSS-TEC data processing has been supported by JSPS KAKENHI Grant Number 16H06286。
文摘This study analyzes total electron content(TEC)variations during two solar eclipse events that occurred on October 25,2022,and October 14,2023.The solar eclipse of October 25,2022,was a partial solar eclipse,while the eclipse of October 14,2023,was an annular solar eclipse.For this study,the data of eight International GNSS Service(IGS)stations from different eclipse coverage zones are used to analyze TEC variations.It is found that the stations located in the maximum eclipse cover zone exhibited notable decreases in TEC values.The minimum variation of about 11.76%in TEC values is observed at the station situating in about 20 percent eclipse cover zone,while it varies from 22%to 38%at the stations falling in about 60 percent eclipse cover zone.The highest variation in TEC values of about 44%is found at the stations in about 80 percent eclipse cover zone.The time of occurrence of maximum depletion in TEC values at each station is in line with their longitudinal sequence.Atmospheric gravity waves(AGWs)are also observed by performing wavelet analysis on TEC data.The global TEC maps visualize and confirm observed TEC variations,providing spatial and temporal insights into the ionospheric response.This analysis highlights the influence of station location and eclipse coverage on the magnitude and spatial distribution of TEC variations.
基金supported by grants, most recently ATM-0552116the Solar Terrestrial Research Program of the U.S. National Science Foundation’s Division of Atmospheric Sciences, the Committee for Research and Exploration of the National Geographic Society, NASA’s Planetary Astronomy Division for the CCD cameras, Sigma Xi, and the Rob Spring Fund and the Ryan Patrick Gaishin Fund at Williams College.
文摘The occasion of the longest totality of an eclipse in the 18 yr 11^1/3 d saros cycle leads to taking stock of the scientific value of ground-based eclipse observations in this space age. Though a number of space satellites from the U.S., Europe, Japan, and Russia study the Sun, scientists at eclipses can observe the solar chromosphere and corona at higher spatial resolution, at higher temporal resolution, and at higher spectral resolution than are possible aloft. Furthermore, eclipse expeditions can transport a wide variety of state-of-the-art equipment to the path of totality. Thus, for at least some years to come, solar eclipse observations will remain both scientifically valuable and cost-effective ways to study the outer solar atmosphere.
基金supported by the National Basic Research Program of China(973 Program Grant No. 2011CB811400)the Joint Doctoral Promotion Programme of the Chinese Academy of Science
文摘Mutual events between natural satellites include mutual occultation and mutual eclipse. Mutual eclipse is another kind of mutual occultation as viewed from the center of the Sun instead of the Earth. Two mutual eclipses of J2 Europa by J1 Io （2009 Aug. 28 and Sept. 12） were observed at Yunnan Observatory during the PHEMU09 international campaign. We will calculate the astrometric data of these Galilean satellites by analyzing and fitting the light curves we obtained. The limb-darkening was considered during modeling the light intensity of eclipsed satellites in the penumbra zone, by taking the Lommel-Seeliger scattering law into account. Several dynamical quantifies, such as the relative coordinates of the eclipsing satellite from the eclipsed one △α cos δ and △δ, impact parameter and mid-time corresponding to the impact parameter and the deviations O - C of observed △α cos d and △δ relative to ephemerides, were obtained for each event respectively.
基金Supported by the National Natural Science Foundation of China.
文摘We describe and analyze observations of mutual events of Galilean satellites made at the Yunnan Observatory in February 2003 from CCD imaging for the first time in China. Astrometric positions were deduced from these photometric observations by modelling the relative motion and the photometry of the involved satellites during each event.
基金partly supported by the West Light Foundation of the Chinese Academy of Sciences, Yunnan Natural Science Foundation (Y5XB071001)the National Natural Science Foundation of China (Grant Nos. 11133007 and 11325315)+2 种基金the Key Research Program of the Chinese Academy of Sciences (Grant No. KGZD-EW-603)the Science Foundation of Yunnan Province (No. 2012HC011)by the Strategic Priority Research Program “The Emergence of Cosmological Structures” of the Chinese Academy of Sciences (No. XDB09010202)
文摘Four candidates of eclipsing multiples, based on new extraneous eclipses found on Kepler binary light curves, are presented and studied. KIC 7622486 is a double eclipsing binary candidate with orbital periods of 2.2799960 d and 40.246503 d. The two binary systems do not eclipse each other in the line of sight, but there is mutual gravitational influence between them which leads to the small but definite eccentricity of 0.0035（0.0022） associated with the short 2.2799960 d period orbit. KIC 7668648 is a hierarchical quadruple system candidate, with two sets of solid 203 4- 5 d period extraneous eclipses and another independent set of extraneous eclipses. A clear and credible extraneous eclipse is found on the binary light curve of KIC 7670485 which makes it a triple system candidate. Two sets of extraneous eclipses with periods of about 390 d and 220 d are found on KIC 8938628 binary curves, which not only confirm the previous conclusion of the 388.5 4- 0.3 triple system, but also indicate new additional objects that make KIC 8938628 a hierarchical quadruple system candidate. The results from these four candidates will contribute to the field of eclipsing multiples.
文摘Thales of Miletus （640？-546 BC） is famous for his prediction of the total solar eclipse in 585 BC. In this paper, the author demonstrate how Thales may have used the same principle for prediction of solar eclipses as that used on the Antikythera Mechanism. At the SEAC conference in Alexandria in 2009, the author presented the paper ＂Ten solar eclipses show that the Antikythera Mechanism was constructed for use on Sicily.＂ The best defined series of exeligmos cycles started in 243 BC during the lifetime of Archimedes （287-212 BC） from Syracuse. The inscriptions on the Antikythera Mechanism were made in 100-150 BC and the last useful exeligmos started in 134 BC. The theory for the motion of the moon was from Hipparchus （ca 190-125 BC）. A more complete investigation of the solar eclipses on the Antikythera Mechanism reveals that the first month in the first saros cycle started with the first new moon after the winter solstice in 542 BC. Four solar eclipses 537-528 BC, from the first saros cycle, and three one exeligmos cycle later, 487-478 BC, are preserved and may have been recorded in Croton by Pythagoras （ca 575-495 BC） and his school.
文摘In abundant old observational records of lunar eclipses in ancient China, some with timing of lunar eclipse phase are significant to the study of secular variation and fluctuation of the Earth’s rotation.Among the over 700 observational records for about 400 lunar eclipses,133 observational times of eclipse phases about
基金supported by the National Natural Science Foundation of China(NSFC)under grant Nos.12473054 and 12127901the Strategic Priority Research Program of the Chinese Academy of Sciences under grant No.XDB0560000+1 种基金Yunnan Key Laboratory of Solar Physics and Space Science under No.202205AG070009Yunnan Fundamental Research Projects under No.202105AC160085.
文摘During the total solar eclipse of 2013 November 3, a fiber-based spectrometer captured the flash spectrum within the wavelength range of 5162–5325Å, with the field-of-view positioned approximately 0.04 R⊙above the east limb, near the second-contact point. This placement near the innermost corona, together with the nearby Baily's beads, enabled the detection of emission lines from the photosphere, lower chromosphere, and corona in the same spectral frame. The higher field-of-view made the coronal line Fe XIV 5303Åmore visible, while the reduced intensity of photospheric and lower chromospheric light, caused by terrestrial scattering, also influenced the observed spectrum. Meanwhile, we selected 18 flash emission lines to measure the ratio of the relative line height of the flash emission line to the relative line depth of the corresponding solar absorption line. This ratio serves as a diagnostic of the source function, minimizing opacity effects. Comparison of disk and flash spectra shows that this ratio increases for spectral lines at greater formation heights, being strongest for chromospheric lines(particularly Fe II), moderate for photospheric low-FIP lines, and weakest for photospheric neutral lines. This trend suggests a rising source function with formation height, potentially linked to increasing electron temperatures or influenced by factors observed in flash spectra near active regions as reported in earlier studies.
文摘A group of Chinese astronomers detected a weird pulsar that keeps emitting radio beams in long,regular pauses.After years of follow-up observations and careful data analyses,they finally revealed this exotic pulsar in Science on May 23 as a rare case:it turns out to be eclipsed by a companion,very likely a helium star,with a mass similar to the Sun and in an orbit smaller than the solar radius.
基金College Students Innovation and Entrepreneurship Project of Pujiang College,Nanjing University of Technology(PJ202413905083)Natural Science Project of Pujiang College,Nanjing University of Technology(njpj2024-1-01)。
文摘To improve the level of sports social management,to achieve standardized management,quick query,scientific statistics of sports social information,and to meet the needs of sports organizers,social platform managers,and other users,this paper introduces a sports social management system based on Spring Boot.The system uses Eclipse for Java Web development,selects MySQL 5.6 database as the background data storage solution,uses Java language to write code,and uses Tomcat server to build the running environment of applications.The system has the function of adding,deleting,changing and checking sports activities,supporting the input,query and statistical analysis of users’sports results,sports consumption and sports distance,and also allows to add,delete,modify and query the information of sports friends,aiming to provide users with a comprehensive and efficient sports social information management platform.
基金a project supported by the Scientific and Technological Research Council of Türkiye (TüB?TAK) under grant No.114F166
文摘We present a comprehensive analysis of BI CVn,an eclipsing overcontact binary system.New BVR photometric observations,combined with available spectroscopic data,were analyzed simultaneously using the Wilson–Devinney method to derive the orbital and physical parameters of the system.The resulting stellar parameters are M1=0.58±0.01M⊙,M2=1.42±0.02M⊙,R1=0.88±0.01R⊙,R2=1.31±0.01R⊙,with an orbital separation of a=2.80±0.01R⊙.Based on all available CCD times of minimum light,including both ground-based and T ESS observations,the(O-C)diagram of BI CVn was analyzed.T he orbital period exhibits a long-term decrease at a rate of-2.3239(±0.0001)×10-8 day yr-1,likely due to mass transfer from the more massive to the less massive component.Superimposed on this trend is a cyclic variation with a period of 56.84±0.08 yr,indicative of a light-travel time effect caused by a third body,whose estimated mass is 0.63±0.02M⊙.Using these derived parameters,we modeled the binary’s evolution through non-conservative processes with the Binary Star Evolution code.The evolutionary tracks of the components were examined in multiple parameter planes,leading to an estimated merger timescale of approximately 2.70 Gyr.
基金support of the staff of the 85 cm,60 cm telescopes at the Xinglong observational station of the National Astronomical Observatories,Chinese Academy of Sciences,and TESS team works funding by the NASA Science Mission directorate.This work is sponsored by the Natural Science Foundation of Xinjiang Uygur Autonomous Region(No.2022D01A164)the National Natural Science Foundation of China(Nos.U1831109 and 12103030)。
文摘Using ground-based telescopes,the multi-color photometric observations of the contact binary EF Boo were obtained in 2020,2023,and 2024.Combining these with 7-sectors of light curves from TESS data,the variations of the O'Connell effect in continuous time and shapes of light curves over several years were identified.Three sets of typical light curves were analyzed to determine the photometric solutions via the Wilson-Devinney program.Considering the spectroscopic mass ratio of q=0.53,these photometric solutions suggest that EF Boo is a W-type W UMa contact binary with the averaged filling factor of f=22.26%,a small temperature difference,and a cool spot on the primary component.If the variations of the O'Connell effect are due to the magnetic activity of this cool spot,the longitudinal location varied from 50.4 to 302.7 over the time interval of 1434 days.Based on all CCD minimum times from ground-based telescope and TESS data,the O-C curve was also analyzed.A cyclic oscillation(A3=0.00575 days,T3=27.8 yr)superimposed on a secular increase(dP/dt=6.74×10^(-8)day yr^(-1))was discovered for the first time.The successive increase is possibly a result of mass transfer from the less massive star to the more massive one.The cyclic oscillations were possibly explained by the light-travel time effect via a third body or the magnetic activities.From the short cadence observations from TESS,we also calculated the value of the O'Connell effect and O-C value for each cycle and found no correlation between the O'Connell effect and O-C over nearly 30 days across different sectors.
