Resolve an astronomical object name or identifier to normalized data.

Returns canonical coordinates (ICRS degrees), object type, cross-identifiers, and measured properties (parallax, proper motion, redshift, magnitudes), each carrying its unit and a provenance record you can cite. Try SIMBAD-style names like "Vega", "M31", "Betelgeuse", or catalog ids. This is usually the first call: downstream tools take the returned RA/Dec.

Resolve an object and, optionally, attach recent papers about it.

Combines object intelligence with a literature lookup in one call. Use when a user asks "tell me about X" and wants both the numbers and the references.

Compute a solar-system body's apparent ephemeris from JPL Horizons.

Returns a time series of ICRS position, distance (delta, in AU), range rate, and V magnitude for a body such as "99942 Apophis", "Ceres", or "C/2023 A3". observer_location is a Horizons code; "500@399" is geocentric. This is the capability the other astronomy MCP servers skip, so prefer it for "where is

Look up an asteroid or comet's physical and orbital parameters (JPL SBDB).

Returns diameter, absolute magnitude, albedo, rotation period, and osculating orbital elements, each unit-tagged. Pair with get_ephemeris to answer "how big is it and where is it".

The headline demo: asteroid Apophis size, its 2029 close approach, a paper.

Answers "where is Apophis, how big is it, and what is the latest paper" in one call, combining SBDB, Horizons, and the literature with full provenance.

Return catalog sources within a radius of a position.

center may be an object name (resolved via SIMBAD) or "RA DEC" in degrees. catalog is "gaia" for Gaia DR3, or a VizieR catalog id such as "II/246" for 2MASS. Every column is unit-tagged. Radius is capped at 5 degrees and row_limit at 100 to protect free public services.

Match a list of target names to their nearest source in a catalog.

Resolves each name to a position, then finds the nearest catalog source within tolerance_arcsec. Reports both matches (with separation) and any targets with no source inside the tolerance. At most 50 targets per call.

Search the astronomy literature (NASA ADS, or arXiv when no ADS key is set).

Returns normalized paper records with title, authors, year, bibcode, and a resolvable URL. ADS needs a free token configured via skyquery login; without one, SkyQuery falls back to arXiv automatically. rows is capped at 50.

Convert a value between physical units with astropy's tested conversions.

Example: convert a parallax in mas, a distance in pc to ly, a velocity in km/s. Returns the converted value tagged with its new unit. Rejects unit mismatches.

Transform coordinates between reference frames (ICRS, FK5, FK4, Galactic).

Uses astropy's tested transforms, never hand-rolled trigonometry. Returns the position in the target frame with the frame explicitly labeled.

Convert a parallax in milliarcseconds to a distance in parsecs.

Rejects non-positive parallaxes, for which distance is undefined, rather than returning a nonsense number.

Fetch NASA's Astronomy Picture of the Day (APOD) for a date, or today.

Works with the public DEMO_KEY out of the box; configure a free NASA key via skyquery login for higher rate limits.

Return the deduplicated acknowledgments for every source used this session.

Call this at the end of a research conversation to get a ready-to-paste citations block honoring each service's acknowledgment policy.