---
name: "hpsplit"
section: "1"
platform: "linux"
package: "astrometry.net"
version: "0.97+dfsg-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/hpsplit"
---

# hpsplit(1)

Split a list of FITS tables into healpix tiles

## NAME

hpsplit - Split a list of FITS tables into healpix tiles

## SYNOPSIS

**hpsplit** \[options\] *input-FITS-catalog* \[...\]

## OPTIONS

- **-o** *pattern*

  Output filename pattern (with %i printf-pattern)

- **-r** *column*

  Name of RA column in FITS table (default RA)

- **-d** *column*

  Name of DEC column in FITS table (default DEC)

- **-n** *Nside*

  Healpix Nside. Default is 1

- **-m** *margin*

  Add a margin of this many degrees around the healpixes; default 0

- **-g**

  Gzip'd inputs

- **-c** *name*

  Copy given column name to the output files

- **-t** *dir*

  Use the given temp dir; default is */tmp*

- **-b** *file*

  Save the filenumber-\>filename map in this file; enables writing backreferences too

- **-v**

  \+verbose

## AUTHOR

The Astrometry.net team. Principal investigators are David W. Hogg (NYU) and Dustin Lang (CMU).

## SEE ALSO

build-astrometry-index (1)\
 For a tutorial, see http://astrometry.net/doc/build-index.html