astropy

1# Astropy
2 
3## Overview
4 
5Astropy is the core Python package for astronomy, providing essential functionality for astronomical research and data analysis. Use astropy for coordinate transformations, unit and quantity calculations, FITS file operations, cosmological calculations, precise time handling, tabular data manipulation, and astronomical image processing.
6 
7## When to Use This Skill
8 
9Use astropy when tasks involve:
10- Converting between celestial coordinate systems (ICRS, Galactic, FK5, AltAz, etc.)
11- Working with physical units and quantities (converting Jy to mJy, parsecs to km, etc.)
12- Reading, writing, or manipulating FITS files (images or tables)
13- Cosmological calculations (luminosity distance, lookback time, Hubble parameter)
14- Precise time handling with different time scales (UTC, TAI, TT, TDB) and formats (JD, MJD, ISO)
15- Table operations (reading catalogs, cross-matching, filtering, joining)
16- WCS transformations between pixel and world coordinates
17- Astronomical constants and calculations
18 
19## Quick Start
20 
21```python
22import astropy.units as u
23from astropy.coordinates import SkyCoord
24from astropy.time import Time
25from astropy.io import fits
26from astropy.table import Table
27from astropy.cosmology import Planck18
28 
29# Units and quantities
30distance = 100 * u.pc
31distance_km = distance.to(u.km)
32 
33# Coordinates
34coord = SkyCoord(ra=10.5*u.degree, dec=41.2*u.degree, frame='icrs')
35coord_galactic = coord.galactic
36 
37# Time
38t = Time('2023-01-15 12:30:00')
39jd = t.jd  # Julian Date
40…