Get FIRST cutouts.

first-cutout.py

import io
import warnings

import requests

def get_first(coord: 'SkyCoord', size: 'arcmin'=5) -> 'FITS image':
    data = {
        'RA': coord.to_string(style='hmsdms', sep=' '),
        'Dec': '',
        'Equinox': 'J2000',
        'ImageSize': size,
        'ImageType': 'FITS Image',
        'MaxInt': 10,
        'Epochs': '',
        'Fieldname': '',
        '.submit': 'Extract the Cutout ',
        '.cgifields': 'ImageType',
    }
    url = 'https://third.ucllnl.org/cgi-bin/firstcutout'
    with warnings.catch_warnings():
        warnings.simplefilter("ignore")
        # This is insecure - prefer verifying if you've got the certs.
        response = requests.post(url, data=data, stream=False, verify=False)
    if response.text.startswith('<PRE>'):
        # Location not in FIRST.
        return
    return astropy.io.fits.open(io.BytesIO(response.content))