from astropy.table import Table
from astropy import log
log.setLevel('WARNING')
import sys

Catherine : interroger un catalogue VizieR depuis une position

def query_vizier_pos(catalogue_name, position, radius=10):
    url = "http://vizier.u-strasbg.fr/viz-bin/votable?-source={}&-c.rs={}&-c={}".format(catalogue_name, radius, position)
    try:
        return Table.read(url) 
    except Exception as e:
        sys.stderr.write("(error)"+str(e)+"\n")
        return None

table = query_vizier_pos("I/239/hip_main", "0+0", radius=120*60)

print(table)

ajouter une contrainte sur la magnitude

import numpy

indices = numpy.where(table["Vmag"]>8)
subtable = table[indices]
print (subtable["HIP"])

subtable = subtable[numpy.where(subtable["Vmag"]<12)]
for rec in subtable:
    print("HIP {: 8d} : {}".format(rec["HIP"], rec["Vmag"]))

mettre a 99.99 les mag>10

from astropy.table import MaskedColumn

b = MaskedColumn(table["Vmag"], mask=table["Vmag"]>9, name="Vmag")
table.remove_column("Vmag")
table.add_column(b)

print (table[:10])

table["Vmag"].fill_value = 99.99
print (table.filled()[:10])