If you have astronomical imaging of the sky with celestial coordinates you do not know—or do not trust—then Astrometry.net is for you. Input an image and we'll give you back astrometric calibration meta-data, plus lists of known objects falling inside the field of view.

Use it. There are currently two options for using the Astrometry.net software: through a web service, or by downloading and building the code and running it on your own computer. Previously we had a service that used the flickr photo-sharing site, but that is currently not working.. web: Our web service is operating at nova.astrometry.net, where you can submit images for astrometric …

Big-Endian Machines¶. Most CPUs these days are little-endian. If you have an Intel or AMD chip, you can skip this section. The most common big-endian CPU in recent times is the PowerPC used in Macs.

Download data. Cleaned USNO-B Catalog: The USNO-B Catalog of astrometric standards contains about 2 percent spurious entries that are caused by diffraction spikes and circular reflection halos around bright stars in the original imaging data. We used computer vision techniques to identify and remove them. Information about getting the clean catalog is …

Project summary. For more specifics about the current state of the project, see the presentation by Roweis to Google Pittsburgh, available here (ppt) or here (pdf). We are building an “astrometry engine” to create correct, standards-compliant astrometric meta data for every useful astronomical image ever taken, past and future, in any state of archival disarray.

Gallery of Solved Images. In the images below, the red circles are stars our algorithm automatically detects in the image, and the green circles are stars from our master index which appear in the query image.

Astrometry.net code README; Change Log: Building/installing the Astrometry.net code; Building Index Files for Astrometry.net; Nova.astrometry.net: API

Astrometry.net index files and other data. Index files -- recommended for most users 4100-series built from the Tycho-2 catalog; scales 7-19 available, good for images wider than 1 degree. Recommended. 5200-series, LIGHT version built from Tycho-2 + Gaia-DR2; scales 0-6 available, good for images narrower than 1 degree. Combine with 4100-series for broader scale coverage.

The subid is the Submission number. The hash is the sha-1 hash of the contents of the URL you specified.. Submitting a file¶. Submitting a file is somewhat complicated, because it has to be formatted as a multipart/form-data form. This is exactly the same way an HTML form with text fields and a file upload field would do it.

The number of healpix tiles is determined by the Nside (-n) option.-n 1 means split the sky into 12 pieces.-n 2 means split the sky into 48 pieces. You probably don’t want to go any finer than that. For reference, maps of the healpix tiles are here: Nside=1 healpixes; Nside=2 healpixes. You probably want to set -m for the margin – extra overlapping area around each healpix tile.