1:45 PM - 3:15 PM
[O07-P24] Study of mechanism of Light Emission by Spectroscopic Observation of Meteor
Keywords:Meteors, Diffraction grating, Spectroscopic observation
1. Purposes
The purpose of this study is to infer the type of elements related to the emission from the spacing of emission lines on the spectroscopic image of meteors, and to clarify the relationship between the altitude and the intensity of the emission lines by observing a meteor simultaneously at multiple points.
2. Hypothesis
・By determining the type and percentage of elements that make up the meteor material from the type and intensity of emission lines, we can clarify the characteristics and tendencies of each meteor shower
・Since the parent bodies of meteor showers are different, the elements detected by observation tend to be different in each meteor shower
・The relationship between the intensity of emission lines and the altitude of the meteor's emission can be derived by simultaneous observations at multiple points, and the mechanism and conditions of meteor emission can be clarified
3. Method
The process of identifying the elements is in the following order.
(1)Take a picture of a meteor with an SLR camera equipped with a diffraction grating and determine the scale of the diffraction grating and the number of pix to each emission line.
(2) Identify the wavelength of each emission line and determine the element from which the emission originates by referring to the literature.
4. Results・Consideration
From the start of the study in 2014 until now, about 570,000 images have been taken and 58 spectral images have been obtained.
One spectroscopic image was obtained for the 2020 Orion meteor shower. Although we estimated three elements from the image, Mg, Na, and Fe, they showed an error of about 10 nm in the measured values. In addition, the emission line estimated to be Fe (529 nm) appeared to be emitted at a slightly earlier than the other two emission lines, suggesting that it may be an oxygen forbidden line (558 nm). These errors may have been caused by incomplete focusing, which obscured the image.
In order to improve the accuracy, we will reconsider the observation method, such as focus adjustment before starting observation and measures against condensation on the lens, especially in winter. Thus, the incident angle of the meteor was tilted to the diffraction grating, which may be the reason for the large error. Therefore, it is necessary to keep the angle of the diffraction grating perpendicular to the radiant point of the meteor shower by rotating the camera by 15 degrees every hour to improve the spectral accuracy.
5. Prospects
We would like to clarify the tendencies of elements in each meteor shower by continuous observation, because there are few meteor showers observed in the same year. We will continue to estimate the altitude and pursue the relationship between the oxygen forbidden line emission and the altitude, because it is difficult to collect the data by simultaneous observation at multiple points at the same time.
The purpose of this study is to infer the type of elements related to the emission from the spacing of emission lines on the spectroscopic image of meteors, and to clarify the relationship between the altitude and the intensity of the emission lines by observing a meteor simultaneously at multiple points.
2. Hypothesis
・By determining the type and percentage of elements that make up the meteor material from the type and intensity of emission lines, we can clarify the characteristics and tendencies of each meteor shower
・Since the parent bodies of meteor showers are different, the elements detected by observation tend to be different in each meteor shower
・The relationship between the intensity of emission lines and the altitude of the meteor's emission can be derived by simultaneous observations at multiple points, and the mechanism and conditions of meteor emission can be clarified
3. Method
The process of identifying the elements is in the following order.
(1)Take a picture of a meteor with an SLR camera equipped with a diffraction grating and determine the scale of the diffraction grating and the number of pix to each emission line.
(2) Identify the wavelength of each emission line and determine the element from which the emission originates by referring to the literature.
4. Results・Consideration
From the start of the study in 2014 until now, about 570,000 images have been taken and 58 spectral images have been obtained.
One spectroscopic image was obtained for the 2020 Orion meteor shower. Although we estimated three elements from the image, Mg, Na, and Fe, they showed an error of about 10 nm in the measured values. In addition, the emission line estimated to be Fe (529 nm) appeared to be emitted at a slightly earlier than the other two emission lines, suggesting that it may be an oxygen forbidden line (558 nm). These errors may have been caused by incomplete focusing, which obscured the image.
In order to improve the accuracy, we will reconsider the observation method, such as focus adjustment before starting observation and measures against condensation on the lens, especially in winter. Thus, the incident angle of the meteor was tilted to the diffraction grating, which may be the reason for the large error. Therefore, it is necessary to keep the angle of the diffraction grating perpendicular to the radiant point of the meteor shower by rotating the camera by 15 degrees every hour to improve the spectral accuracy.
5. Prospects
We would like to clarify the tendencies of elements in each meteor shower by continuous observation, because there are few meteor showers observed in the same year. We will continue to estimate the altitude and pursue the relationship between the oxygen forbidden line emission and the altitude, because it is difficult to collect the data by simultaneous observation at multiple points at the same time.