A name.
A star to discover.

The star type reflects the luminosity class in the Hipparcos spectrum: V, main-sequence dwarf; IV, subgiant; III, giant; II, bright giant; I, supergiant. White dwarfs and Wolf–Rayet stars form separate families when explicitly identified.

The spectral letter O, B, A, F, G, K or M mainly indicates temperature. A class V dwarf can be larger than the Sun. Luminosity class therefore cannot be inferred from diameter alone and does not directly give an age. Intermediate classes and catalogue uncertainties are retained; for a composite spectrum, the type describes the first classified component. When the classification is insufficient, the type remains “undetermined”.

References: NASA/Chandra · luminosity classes and STScI/IVOA · spectral notation.

Distances are estimated by inverting a positive Hipparcos parallax with a relative uncertainty no greater than 20%. The stated interval propagates one standard deviation of parallax; it is not a Bayesian distance estimate. Other distances remain unreported.

Temperature uses Gaia DR3 photometric parameters when available. Otherwise, the B−V index provides a blackbody approximation, limited to −0.3 ≤ B−V ≤ 1.7 and without a reddening correction. Dust, variable stars, multiple systems and models can affect the results.

A diameter relative to the Sun is calculated only when Gaia’s total luminosity and temperature are available and consistent with the published radius: R/R☉ = √(L/L☉) × (5 772 K/T)². The diameter ratio equals the radius ratio. The displayed Gaia intervals are formal and do not necessarily include all systematic effects. Missing values are not invented.

The displayed ages are calculated by Gaia DR3’s FLAME module through comparison with evolutionary models at solar metallicity. The bounds are the model’s 16th and 84th percentiles, a formal 68% interval that does not cover all systematic uncertainties.

The site retains quality flags 00 and, for giants of 1 to 2 solar masses older than one billion years, 10. No age is assigned to explicitly composite spectra or families outside the selected domain. A star without sufficient data retains “age undetermined”: its theoretical lifespan does not give its current age.

Gaia DR3 · FLAME, method and caveats · All portal sources and licences

Credit: ESA. The Hipparcos and Tycho Catalogues, ESA 1997, table I/239/hip_main · CDS/VizieR. Data licensed under CC BY-NC 3.0 IGO, for non-commercial use with attribution. Extract saved on 19 October 2026.

Gaia data: ESA/Gaia/DPAC, Gaia DR3, astrophysical_parameters and hipparcos2_best_neighbour tables; the same CC BY-NC 3.0 IGO licence applies. Parameters were matched through HIP2 single-neighbour associations. FLAME method and limitations.

Adaptations: selection of the 5 044 identifiers already used in the planetarium; astrometry and photometry retrieved directly from Hipparcos; propagation of ICRS positions from 1991.25 to 2000 using proper motion; three entries use the indicative H3/H4 positions; distances and solar comparisons calculated as explained above. Colour temperatures follow Ballesteros (2012). Adapted dataset · compressed JSON.

Names and designations: original indexes referenced by d3-celestial, Olaf Frohn ; three-clause BSD licence. Translations of sky cultures are not included. Constellations are determined from their regional boundaries by Astronomy Engine. Astronomy Engine, Don Cross, MIT licence.