""" StarCatalog """
import math
import gzip
from .star import Star
from .catalog import Catalog
# class name should be "Catalog" following by the name of the catalog - this is used elsewhere
[docs]
class CatalogSAO(Catalog):
""" CatalogSAO()
Smithsonian Astrophysical Observatory
https://heasarc.gsfc.nasa.gov/W3Browse/star-catalog/sao.html
http://tdc-www.harvard.edu/catalogs/sao.html
"""
base_url = 'https://heasarc.gsfc.nasa.gov/FTP/heasarc/dbase/dump/'
source_files = [
'heasarc_sao.tdat.gz',
]
def _readstarfile(self, directory, max_mag, star_append):
""" _readstarfile() """
filename = directory / self.source_files[0]
# <HEADER>
# ...
# field[name] = char10 [meta.id;meta.main] (index) // SAO Catalog Designation
# field[ra] = float8:.6f_degree [pos.eq.ra;meta.main] (key) // Right Ascension
# field[proper_motion_ra] = float8:7.4f_arcsec/yr [pos.pm;pos.eq.ra] // Annual RA Proper Motion (FK4 System)
# field[proper_motion_ra_error] = int1:2d_mas/yr [stat.error;pos.pm;pos.eq.ra] // Standard Deviation in RA Proper Motion (FK4 System)
# field[ra_epoch] = float8:6.1f_yr [time.start;obs] // RA Original Epoch
# field[dec] = float8:.6f_degree [pos.eq.dec;meta.main] (key) // Declination
# field[proper_motion_dec] = float8:6.3f_arcsec/yr [pos.pm;pos.eq.dec] // Annual Declination Proper Motion (FK4 System)
# field[proper_motion_dec_error] = int1:2d_mas/yr [stat.error;pos.pm;pos.eq.dec] // Standard Deviation of Declination Proper Motion (FK4 System)
# field[dec_epoch] = float8:6.1f_yr [time.start;obs] // Declination Original Epoch
# field[position_error] = float8:4.2f_arcsec [stat.error;pos] // Standard Deviation of Position at Epoch 1950.0
# field[lii] = float8:.6f_degree [pos.galactic.lon] (index) // Galactic Longitude
# field[bii] = float8:.6f_degree [pos.galactic.lat] (index) // Galactic Latitude
# field[pg_mag] = float8:4.1f [phot.mag;em.opt] (index) // Photographic Magnitude
# field[vmag] = float8:4.1f [phot.mag;em.opt.V] (index) // Visual Magnitude
# ...
# <DATA>
# SAO 258660|218.82525833|-0.1169|3|1903.6|-89.771625|-0.004|2|1903|0.13|303.04406295|-26.92288489||6.6|M0|14|3|0|1|0|0|70|17838|CP-89 37|110994|0|17838|-0.3021|-0.003|2700|
# SAO 258546|130.4839375|0.0507|9|1904|-89.46084444|-0.025|9|1903.7|0.42|302.3963721|-26.8772436||7.5|K2|14|3|0|1|0|0|70|13496|CP-88 95|90105|0|13496|0.0294|-0.024|2620|
n_lines = 0
in_data_section = False
with gzip.open(filename, 'rt', encoding='utf-8') as fd:
for line in fd.readlines():
line = line.rstrip()
if not in_data_section:
if '<DATA>' == line:
in_data_section = True
continue
if '<HEADER>' == line:
in_data_section = False
continue
if '<END>' == line:
break
n_lines += 1
a = line.split('|')
name = a[1-1]
hd = int(name[4:])
ra = a[2-1]
dec = a[6-1]
vmag = a[14-1]
try:
hd = int(hd)
except ValueError:
hd = None
try:
ra_hrs, ra_min, ra_sec = [float(x) for x in (ra[0:2], ra[3:5], ra[6:])]
ra_f = math.radians((ra_hrs + ra_min/60.0 + ra_sec/3600.0) * 15.0)
except ValueError as e:
# self.__class__.log.debug(type(e).__name__, e, 'RA:', ra[0:2], line[3:5], line[6:], 'Line:', line.rstrip())
ra_f = float('nan')
try:
dec_deg, dec_min, dec_sec = [float(x) for x in (dec[0:3], dec[4:6], dec[7:])]
# NB in the Southern Hemisphere be careful to subtract the minutes and seconds from the (negative) degrees.
dec_sign = math.copysign(1, dec_deg)
dec_f = math.radians(dec_deg + dec_sign * dec_min/60.0 + dec_sign * dec_sec/3600.0)
except ValueError as e:
# self.__class__.log.debug(type(e).__name__, e, 'DEC:', dec[0:3], dec[4:6], dec[7:], 'Line:', line.rstrip())
dec_f = float('nan')
try:
mag_f = float(vmag)
if max_mag and mag_f >= max_mag:
continue
except ValueError as e:
# some stars do not have magnitudes
# self.__class__.log.debug(type(e).__name__, e, 'Mag:', vmag, 'Line:', line.rstrip())
if max_mag:
continue
mag_f = float('nan')
star_append(Star(hd, None, None, ra_f, dec_f, mag_f))
return n_lines