[AstroPy] problems with astroplan

[Steven Boada]

Hi list,

I'm headed to KPNO and I'm trying out astroplan for the first time. But 
I'm getting some confusing output. Here's an example.

from astroplan import Observer, FixedTarget
from astropy.coordinates import SkyCoord

# make telescope location
kpno = Observer.at_site('KPNO')

# make target coordinates
coords = SkyCoord(131.1331774, 62.41165761, unit='deg', frame='icrs')

# make all the targets
target = [FixedTarget(name='test', coord=coords)]

# make the observing time
start_time = Time('2016-11-11 01:54:00')
end_time = Time('2016-11-11 12:30:00')
time_delta = end_time - start_time
observable_time = start_time + time_delta * np.linspace(0,1,75)

print(kpno.target_is_up(start_time, target))
# should print True

# now we try to do all the fancy scheduling
# set our only constraint to be at night
constraint = AtNightConstraint.twilight_civil()

print(astroplan.is_observable(constraint, kpno, targets[:1], 
times=Time('2016-11-11')))
# should print false.


Looking up the airmass etc. on the web, the target is certainly visible 
from KPNO. I'm obviously missing something, but I can't seem to figure 
out what it is.

Thanks for your help.


steven


-- 

Steven Boada

Postdoctoral Researcher
Rutgers University
boada at physics.rutgers.edu