98 Herculis
Scientific overview
98 Herculis is a hypergiant in the constellation Hercules (Herculis), lying about 737.9 light-years from Earth.
Class M. Cool red stars. The most common type in the galaxy, ranging from red dwarfs to red giants. Such stars have surface temperatures around 2,400–3,700 K and appear red to the eye.
Physical properties
| Spectral type | M3IIIa+... |
| Luminosity class | Ia+ |
| Apparent magnitude | 4.96 |
| Absolute magnitude | -1.81 |
| Luminosity (Sun = 1) | 463 |
| Colour index (B−V) | 1.656 |
| Distance | 737.9 ly (226.24 pc) |
Values are real catalogue data; fields without a reliable value are omitted, never estimated.
Precision measurements
Astrometry and astrophysics from SIMBAD and Gaia DR3 · Gaia DR3 4576646442581655040 · elevated RUWE
| Parallax | 5.5451 ± 0.1667 mas | SIMBAD · measured |
| Distance | 180.2 pc | Gaia · estimated |
| Proper motion (RA) | -12.557 mas/yr | SIMBAD · measured |
| Proper motion (Dec) | -6.89 mas/yr | SIMBAD · measured |
| Radial velocity | -19.48 ± 0.21 km/s | SIMBAD · measured |
| Spectral type | M3-SIII | SIMBAD · catalogued |
| Right ascension (ICRS) | 271.5 deg | SIMBAD · measured |
| Declination (ICRS) | 22.2189 deg | SIMBAD · measured |
Full field-level provenance
- Parallax: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · plx_value · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
- Distance: ESA Gaia astrometric survey · Gaia EDR3 · Bailer-Jones (2021) · external.gaiaedr3_distance · r_med_geo · row 4576646442581655040 · Bayesian estimate · retrieved 2026-07-11
- Proper motion (RA): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · pmra · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
- Proper motion (Dec): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · pmdec · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
- Radial velocity: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · rvz_radvel · 2005A&A...430..165F · direct catalogue measurement · retrieved 2026-07-11
- Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · 1989ApJS...71..245K · catalogue identifier/value · retrieved 2026-07-11
- Right ascension (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · ra · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
- Declination (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · dec · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
measured = direct catalogue value · estimated = Bayesian inference (Bailer-Jones distance) · modeled = model output (Gaia GSP-Phot). Fields a source did not provide are omitted, never invented.
Evolution
A hypergiant is an exceptionally massive and luminous star, losing mass at a tremendous rate. Hypergiants are extraordinarily rare and short-lived.
Location in the sky
Knowledge connections
- In constellationHercules
Related stars in Hercules
Sources
The primary and reference sources this topic draws on.
- HYG DatabaseHYG Database (Hipparcos + Yale Bright Star + Gliese), by D. Nash / astronexus
Aggregated, openly-licensed star catalogue combining Hipparcos, the Yale Bright Star Catalogue, and the Gliese Catalogue of Nearby Stars.
- HipparcosESA Hipparcos space astrometry mission
High-precision parallax, magnitude, and position for ~118,000 stars.