In this work,we report observations of three comets:38P/Stephan-Oterma,64P/Swift-Gehrels,and C/2017 M4(ATLAS),conducted with the Nanshan one-meter wide-field telescope in 2018 August and November,and 2019January.We ex...In this work,we report observations of three comets:38P/Stephan-Oterma,64P/Swift-Gehrels,and C/2017 M4(ATLAS),conducted with the Nanshan one-meter wide-field telescope in 2018 August and November,and 2019January.We extracted morphological features through image enhancement techniques and calculated the dust activity parameter,Afρ,along with dust mass loss rates and coma color indices using broadband photometric data.Our morphological analysis uncovered a spectrum of dust characteristics among the observed comets,ranging from a significant twisted structure in comet 38P/Stephan-Oterma’s coma to the regular coma envelope surrounding comet 64P/Swift-Gehrels.The Afρvalues varied between 148.8±0.3 cm for 64P/Swift-Gehrels and1118.5±6.2 cm for C/2017 M4(ATLAS)(measured within a reference aperture radius ofρ=6″),indicating a range from moderate to high activity levels.Dust mass loss rates were estimated from 328.1 kg s^(-1)for comet 64P/Swift-Gehrels to 1395.5 kg s^(-1)for comet C/2017 M4(ATLAS).The color indices of comets 38P/Stephan-Oterma and C/2017 M4(ATLAS)closely resemble the average colors of active short-period comets and active longperiod comets,respectively.In contrast,64P/Swift-Gehrels exhibits a significantly bluer hue than typical Jupiter family comets.展开更多
In this work, we report the observations of the long-period comet C/2015 O1 performed on2018 January 29–30 and April 13 with the Nanshan 1-meter wide-field telescope operated by Xinjiang Astronomical Observatory. We ...In this work, we report the observations of the long-period comet C/2015 O1 performed on2018 January 29–30 and April 13 with the Nanshan 1-meter wide-field telescope operated by Xinjiang Astronomical Observatory. We obtain the morphological features of C/2015 O1 using an image enhancement method, and calculate the dust-activity parameter Afρ and the coma color based on photometric analysis. An obvious fan-shaped structure was observed at different observation times. We find that the activity of C/2015 O1 gradually decreases as the comet advances toward perihelion and the observed B-V and V-R colors are consistent with those of other comets.展开更多
High resolution, high signal-to-noise ratio spectra of Comet C/1995 O1 (Hale-Bopp) which provided continuous wavelength coverage from 5500 to 8500 and partial coverage from 4000 to 5500 were obtained with ...High resolution, high signal-to-noise ratio spectra of Comet C/1995 O1 (Hale-Bopp) which provided continuous wavelength coverage from 5500 to 8500 and partial coverage from 4000 to 5500 were obtained with Coudé Echelle Spectrograph at Beijing Astronomical Observ atory on March 26, 28 and April 22, 1997. In the spectra we found 751 emission features among which 577 lines from H, O, Na, C 2, C 3, CN, CH, NH 2, H 2O + were identified.展开更多
基金supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region of China(grant No.2021D01B112)Tianshan Talent Training Program through the grant 2023TSYCCX0101。
文摘In this work,we report observations of three comets:38P/Stephan-Oterma,64P/Swift-Gehrels,and C/2017 M4(ATLAS),conducted with the Nanshan one-meter wide-field telescope in 2018 August and November,and 2019January.We extracted morphological features through image enhancement techniques and calculated the dust activity parameter,Afρ,along with dust mass loss rates and coma color indices using broadband photometric data.Our morphological analysis uncovered a spectrum of dust characteristics among the observed comets,ranging from a significant twisted structure in comet 38P/Stephan-Oterma’s coma to the regular coma envelope surrounding comet 64P/Swift-Gehrels.The Afρvalues varied between 148.8±0.3 cm for 64P/Swift-Gehrels and1118.5±6.2 cm for C/2017 M4(ATLAS)(measured within a reference aperture radius ofρ=6″),indicating a range from moderate to high activity levels.Dust mass loss rates were estimated from 328.1 kg s^(-1)for comet 64P/Swift-Gehrels to 1395.5 kg s^(-1)for comet C/2017 M4(ATLAS).The color indices of comets 38P/Stephan-Oterma and C/2017 M4(ATLAS)closely resemble the average colors of active short-period comets and active longperiod comets,respectively.In contrast,64P/Swift-Gehrels exhibits a significantly bluer hue than typical Jupiter family comets.
基金supported by the program of the light in China’s Western Region (LCWR, Grant No. 2015XBQN-A-02)the National Natural Science Foundation of China (Grant No. 11661161016)+2 种基金the 13th Five-year Informatization Plan of Chinese Academy of Sciences (Grant No. XXH13503–03–107)the Youth Innovation Promotion Association CAS (Grant No. 2018080)the Talent Importing Program offered by the government of Xinjiang Uygur Autonomous Region
文摘In this work, we report the observations of the long-period comet C/2015 O1 performed on2018 January 29–30 and April 13 with the Nanshan 1-meter wide-field telescope operated by Xinjiang Astronomical Observatory. We obtain the morphological features of C/2015 O1 using an image enhancement method, and calculate the dust-activity parameter Afρ and the coma color based on photometric analysis. An obvious fan-shaped structure was observed at different observation times. We find that the activity of C/2015 O1 gradually decreases as the comet advances toward perihelion and the observed B-V and V-R colors are consistent with those of other comets.
文摘High resolution, high signal-to-noise ratio spectra of Comet C/1995 O1 (Hale-Bopp) which provided continuous wavelength coverage from 5500 to 8500 and partial coverage from 4000 to 5500 were obtained with Coudé Echelle Spectrograph at Beijing Astronomical Observ atory on March 26, 28 and April 22, 1997. In the spectra we found 751 emission features among which 577 lines from H, O, Na, C 2, C 3, CN, CH, NH 2, H 2O + were identified.
