code: def fetch_halpha(self, correct=True, median_kernel=5):
          
  
          if self.verbose:
              print("Requesting halpha")
  
          def time_interval(time):
              """ get a window of three minutes around the requested time to ensure an image at GONG cadence"""
              return time - timedelta(minutes=3), time + timedelta(minutes=3)
  
          # setup the query for an halpha image and fetch, saving the image in the current directory
          client = vso.VSOClient()
          halpha, source = Quantity(656.28, "nm"), "gong"
          query = client.search(vso.attrs.Time(*time_interval(self.date)),
                                vso.attrs.Source(source),
                                vso.attrs.Wavelength(halpha))
  
          if not query: # no images found in query
              return "halpha", None, None
          else:
              query = query[0]
  
          result = client.fetch([query], path="./").wait(progress=False)
          time.sleep(1) # sleep because on macs there's sometimes a bug where the file isn't recognized if you dont...
  
          # open the image and remove the file
          with fits.open(result[0]) as hdu:
              head = hdu[1].header
              data = hdu[1].data
          os.remove(result[0])
  
          # scale halpha to suvi
          scale = 2.35
          tform = AffineTransform(scale=(scale, scale))  # , translation=(-1280/2,-1280/2))
          data = warp(data, tform, output_shape=(1280, 1280))
          tform = AffineTransform(
              translation=(-(640 - 1024 / scale), -(640 - 1024 / scale)))
          data = warp(data, tform)
  
          if correct:
              data[np.isnan(data)] = 0
              data[data < 0] = 0
  
          if median_kernel:
              data = medfilt(data, median_kernel)
  
          return "halpha", head, data
docs: pull halpha from that time from Virtual Solar Observatory GONG archive
          :param correct: remove nans and negatives
          :return: tuple of "halpha", a fits header, and data object for the GONG image at that time
              header and data will be None if request failed