これは日々の作業を通して学んだことや毎日の生活で気づいたことをを記録しておく備忘録である。
HTML ファイル生成日時: 2024/12/21 11:44:57.596 (台灣標準時)
sbpy という Python のパッケージがある ことを知ったので、試してみたでござる。日時と観測地点を指定し、 JPL Horizons を使って小惑星の位置を調べ、高度と等級の条件を満たす小惑星が 見つかったら、その小惑星についての情報を書き出す、というプログラムを書 いてみたでござる。
書いてみたプログラムは以下の通りでござる。
#!/usr/pkg/bin/python3.10 # # Time-stamp: <2023/06/23 21:51:33 (CST) daisuke> # # importing argparse module import argparse # importing sbpy module import sbpy.data # importing astropy module import astropy.time import astropy.units # initialising a parser of argparse parser = argparse.ArgumentParser (description='Finding observable asteroids') # adding arguments parser.add_argument ('-t1', '--time1', default='2000-01-01T00:00', \ help='start time in UT (default: 2000-01-01T00:00)') parser.add_argument ('-t2', '--time2', default='2000-01-02T00:00', \ help='end time in UT (default: 2000-01-02T00:00)') parser.add_argument ('-d', '--dt', type=float, default=1.0, \ help='time step in hour for ephemeris (default: 1.0)') parser.add_argument ('-n', '--number', type=int, default=10, \ help='number of asteroids for search (default: 10)') parser.add_argument ('-a', '--alt', type=float, default=30.0, \ help='acceptable altitude (default: 30.0 deg)') parser.add_argument ('-s', '--site', default='D35', \ help='observatory site (default: D35)') parser.add_argument ('-m', '--mag', type=float, default=18.0, \ help='limiting magnitude in V-band (default: 20.0)') parser.add_argument ('-o', '--output', default='asteroids.list', \ help='output file name (default: asteroids.list)') # parsing arguments args = parser.parse_args () # given arguments time_start = args.time1 time_end = args.time2 step_hr = args.dt n_asteroids = args.number req_alt = args.alt obs_site = args.site limmag_V = args.mag file_output = args.output # units u_hr = astropy.units.hour u_deg = astropy.units.deg u_mag = astropy.units.mag # bar bar1 = '-' * 71 bar2 = '=' * 78 # date/time in UT in astropy.time format datetime_start_str = time_start datetime_stop_str = time_end step = step_hr * u_hr datetime_start = astropy.time.Time (datetime_start_str, scale='utc') datetime_stop = astropy.time.Time (datetime_stop_str, scale='utc') datetime = {'start': datetime_start, \ 'stop': datetime_stop, \ 'step': step} # opening output file for writing with open (file_output, 'w') as fh_output: # input parameters fh_output.write (f'# time_start = {time_start}\n') fh_output.write (f'# time_end = {time_end}\n') fh_output.write (f'# time step = {step_hr}\n') fh_output.write (f'# n_asteroids = {n_asteroids}\n') fh_output.write (f'# req_alt = {req_alt}\n') fh_output.write (f'# obs_site = {obs_site}\n') fh_output.write (f'# limmag_V = {limmag_V}\n') fh_output.write (f'# file_output = {file_output}\n') fh_output.write (f'{bar2}\n') # ephemeris for i in range (1, n_asteroids + 1): eph = sbpy.data.Ephem.from_horizons (i, \ location=obs_site, \ epochs=datetime) # a flag for visibility observable = 1 # check of visibility for j in range (len (eph)): if (eph["EL"][j].value < req_alt): observable = 0 # check of apparent V-band magnitude for j in range (len (eph)): if (eph["V"][j].value > limmag_V): observable = 0 # printing ephemeris if (observable): fh_output.write (f'{eph["targetname"][0]}\n') fh_output.write (f' Date/Time RA Dec') fh_output.write (f' Az El R Delta alpha V-mag\n') fh_output.write (f' {bar1}\n') for j in range (len (eph)): time_jd = eph["epoch"][j] time_isot = time_jd.to_value ('isot') fh_output.write (f' {time_isot}') fh_output.write (f' {eph["RA"][j].value:5.1f}') fh_output.write (f' {eph["DEC"][j].value:+5.1f}') fh_output.write (f' {eph["AZ"][j].value:5.1f}') fh_output.write (f' {eph["EL"][j].value:+5.1f}') fh_output.write (f' {eph["r"][j].value:5.1f}') fh_output.write (f' {eph["delta"][j].value:5.1f}') fh_output.write (f' {eph["alpha"][j].value:5.1f}') fh_output.write (f' {eph["V"][j].value:5.2f}\n') fh_output.write (f'{bar2}\n')
使い方は、以下の通りでござる。
% ./sbpy_search_asteroids.py -h usage: sbpy_search_asteroids.py [-h] [-t1 TIME1] [-t2 TIME2] [-d DT] [-n NUMBER] [-a ALT] [-s SITE] [-m MAG] [-o OUTPUT] Finding observable asteroids options: -h, --help show this help message and exit -t1 TIME1, --time1 TIME1 start time in UT (default: 2000-01-01T00:00) -t2 TIME2, --time2 TIME2 end time in UT (default: 2000-01-02T00:00) -d DT, --dt DT time step in hour for ephemeris (default: 1.0) -n NUMBER, --number NUMBER number of asteroids for search (default: 10) -a ALT, --alt ALT acceptable altitude (default: 30.0 deg) -s SITE, --site SITE observatory site (default: D35) -m MAG, --mag MAG limiting magnitude in V-band (default: 20.0) -o OUTPUT, --output OUTPUT output file name (default: asteroids.list)
実行結果の例は、以下の通りでござる。
% ./sbpy_search_asteroids.py -t1 2023-07-01T14:00:00 -t2 2023-07-01T18:00:00 \ ? -d 1 -n 500 -a 35 -s D35 -m 17 -o asteroids_20230701.list % ls -lF asteroids_20230701.list -rw-r--r-- 1 daisuke taiwan 4005 Jun 23 21:58 asteroids_20230701.list % cat asteroids_20230701.list # time_start = 2023-07-01T14:00:00 # time_end = 2023-07-01T18:00:00 # time step = 1.0 # n_asteroids = 500 # req_alt = 35.0 # obs_site = D35 # limmag_V = 17.0 # file_output = asteroids_20230701.list ============================================================================== 34 Circe (A855 GA) Date/Time RA Dec Az El R Delta alpha V-mag ----------------------------------------------------------------------- 2023-07-01T14:00:00.000 271.7 -14.9 148.8 +46.2 2.8 1.8 4.1 12.57 2023-07-01T15:00:00.000 271.7 -14.9 169.6 +51.1 2.8 1.8 4.1 12.57 2023-07-01T16:00:00.000 271.7 -14.9 192.8 +50.8 2.8 1.8 4.1 12.57 2023-07-01T17:00:00.000 271.6 -14.9 213.1 +45.4 2.8 1.8 4.1 12.57 2023-07-01T18:00:00.000 271.6 -14.9 228.2 +36.3 2.8 1.8 4.1 12.57 ============================================================================== 153 Hilda (A875 VC) Date/Time RA Dec Az El R Delta alpha V-mag ----------------------------------------------------------------------- 2023-07-01T14:00:00.000 270.9 -15.5 150.2 +45.9 3.4 2.4 3.4 12.58 2023-07-01T15:00:00.000 270.9 -15.5 170.9 +50.6 3.4 2.4 3.4 12.58 2023-07-01T16:00:00.000 270.9 -15.5 193.6 +50.0 3.4 2.4 3.4 12.58 2023-07-01T17:00:00.000 270.9 -15.5 213.4 +44.4 3.4 2.4 3.4 12.58 2023-07-01T18:00:00.000 270.9 -15.5 228.2 +35.4 3.4 2.4 3.4 12.58 ============================================================================== 242 Kriemhild (A884 SA) Date/Time RA Dec Az El R Delta alpha V-mag ----------------------------------------------------------------------- 2023-07-01T14:00:00.000 277.9 -7.4 135.1 +48.8 3.2 2.2 5.0 14.04 2023-07-01T15:00:00.000 277.9 -7.4 156.1 +56.6 3.2 2.2 5.0 14.04 2023-07-01T16:00:00.000 277.9 -7.4 184.0 +59.1 3.2 2.2 5.0 14.04 2023-07-01T17:00:00.000 277.9 -7.4 210.5 +54.9 3.2 2.2 5.0 14.04 2023-07-01T18:00:00.000 277.9 -7.4 229.4 +45.9 3.2 2.2 5.0 14.04 ============================================================================== 246 Asporina (A885 EA) Date/Time RA Dec Az El R Delta alpha V-mag ----------------------------------------------------------------------- 2023-07-01T14:00:00.000 278.6 +0.6 125.4 +54.0 2.4 1.5 9.8 11.86 2023-07-01T15:00:00.000 278.6 +0.6 148.1 +63.6 2.4 1.5 9.8 11.86 2023-07-01T16:00:00.000 278.5 +0.6 183.8 +67.1 2.4 1.5 9.8 11.86 2023-07-01T17:00:00.000 278.5 +0.6 217.4 +62.1 2.4 1.5 9.7 11.86 2023-07-01T18:00:00.000 278.5 +0.6 237.8 +51.8 2.4 1.5 9.7 11.86 ============================================================================== 393 Lampetia (A894 VC) Date/Time RA Dec Az El R Delta alpha V-mag ----------------------------------------------------------------------- 2023-07-01T14:00:00.000 285.3 +6.7 110.6 +52.1 1.9 0.9 15.7 10.53 2023-07-01T15:00:00.000 285.3 +6.7 127.4 +64.3 1.9 0.9 15.7 10.53 2023-07-01T16:00:00.000 285.3 +6.7 162.4 +72.5 1.9 0.9 15.7 10.53 2023-07-01T17:00:00.000 285.3 +6.7 210.9 +70.8 1.9 0.9 15.7 10.53 2023-07-01T18:00:00.000 285.3 +6.7 238.9 +60.8 1.9 0.9 15.7 10.53 ============================================================================== 417 Suevia (A896 JB) Date/Time RA Dec Az El R Delta alpha V-mag ----------------------------------------------------------------------- 2023-07-01T14:00:00.000 280.5 -12.7 137.2 +43.0 2.8 1.8 3.8 13.39 2023-07-01T15:00:00.000 280.5 -12.7 155.5 +50.8 2.8 1.8 3.8 13.39 2023-07-01T16:00:00.000 280.5 -12.7 179.1 +53.8 2.8 1.8 3.8 13.39 2023-07-01T17:00:00.000 280.5 -12.7 203.0 +51.1 2.8 1.8 3.8 13.39 2023-07-01T18:00:00.000 280.5 -12.7 221.8 +43.7 2.8 1.8 3.8 13.39 ==============================================================================