HIP 66074 b

HIP 66074 b — Exoplanet profile
Exoplanet profile

HIP 66074 b

Host star: HIP 66074 • Discovery: 2023 • Method: Astrometry
derived planet • updated: 2023-10-24
candidate derived modeled atmosphere derived

HIP 66074 b orbits a cool, small star called HIP 66074. Scientists found it by measuring tiny wobbles in the star’s position across the sky — a technique called astrometry — using data from the European Space Agency’s Gaia satellite.

What this page represents

This page summarizes a catalog entry. If a measurement is missing, it is not shown or guessed. Some values can differ slightly between studies; when that happens, we describe the range rather than picking a favorite without evidence.

Scientific context

Scientific context: This profile layers interpretation on top of archival measurements. Modeled bands appear where direct detections (like spectra or transits) are not listed.

Signal quality
weak
Distance
115.6 ly
Star temp
4300 K
Mass
5.0 MJ (m·sin i)
What we can infer: broad planet class (rocky vs gas), rough irradiation band via star temperature + distance, and signal robustness.
What we can’t claim: surface conditions, biology, or breathable atmosphere without direct spectra.
overview
plain-language interpretation + what’s missing made explicit

This planet has a mass about 5 times that of Jupiter and orbits its star at an average distance of 0.8 times Earth’s distance from the Sun. Its orbit is extremely stretched out (eccentricity of 0.948), meaning it swings very close to and far from its star during each orbit. Because it was found by astrometry, we know its true mass — not just a minimum estimate — but we don’t know its size or what its atmosphere might be like.

Glossary (plain English)
  • AU: the average Earth–Sun distance.
  • Semi-major axis: the planet’s average distance from its star.
  • Eccentricity: how oval the orbit is (0 = circle).
  • Radial velocity: finding a planet by measuring a star’s tiny “wobble.”
  • m·sin i: a minimum mass estimate; the true mass can be higher if the orbit is tilted.
  • Equilibrium temperature: a rough estimate from starlight alone, not a surface reading.
Semi-major axis
0.80 AU
Meaning: average distance from the star (Earth = 1 AU).
Eccentricity
0.95
Meaning: how oval the orbit is (0 is a circle).
Host star type
—
A spectral label that summarizes temperature and color.
Host star radius
0.69 R⊙
Bigger stars can change how “hot” a planet’s orbit feels.
Metallicity
0.12
Meaning: how “heavy-element rich” the star is vs the Sun.
Distance
115.6 ly
How far the system is from Earth (in light-years).
About the numbers on this page: this profile combines measurements reported across multiple published studies. It uses the most consistent values and explains where estimates vary.
discovery and follow-up
why the same planet can appear in multiple catalog rows

HIP 66074 b was first reported in 2023 using the Astrometry method.

The discovery is linked to observations from European Space Agency (ESA) Gaia Satellite. Different methods emphasize different strengths: some constrain size, some constrain mass, and some constrain both.

orbit and long-term stability
a plain-English read of the orbit, plus what “uncertainty” means here

The catalog lists an orbital period of about 310.90 days, a semi-major axis near 0.799 AU.

The orbit’s eccentricity is 0.95, which describes how stretched the orbit is. A higher eccentricity can imply stronger past interactions or migration, and it can matter for long‑term stability in multi‑planet systems.

Reader tip: small differences across studies usually reflect better data and improved fitting — not that the planet “changed.”
mass, “minimum mass,” and why estimates differ
radial velocity usually measures a minimum mass unless the orbit tilt is known

The archive reports a mass scale of 5.0 MJ.

A rough radius estimate is shown for UI completeness, but it should not be treated as a measurement.

Why “m·sin i” shows up on RV planets
Radial velocity detects a star’s wobble. If we don’t know the orbit’s tilt (inclination), the wobble gives a minimum mass. The true mass can be higher.
the host star in plain terms
star properties affect temperature estimates and “how intense” the orbit feels

HIP 66074 b orbits HIP 66074.

A temperature near 4300 K places it on the cool side of the main sequence. The system is about 115.6 light‑years away.

what we still don’t know
missing measurements that limit what anyone can responsibly claim

Several key parameters are not present in this single catalog row. Missing fields don’t mean the science is unknown—only that this particular snapshot doesn’t carry the values.

In this case the most noticeable gaps are: radius, catalog equilibrium temperature. As new observations arrive, archives often refresh these entries (and sometimes revise earlier numbers).

Why this matters: without a measured radius or direct spectra, we can’t reliably infer density, surface conditions, or detailed chemistry.
observation charts
visual summaries from method + uncertainty bands (no spectra required)
radial velocity curve
Dashed segment indicates modeled RV window. Period: 311 d • e: 0.95 • a: 0.80 AU
orbit stability
signal-to-noise proxy
39% stability
Transit fit
Noise floor
Data density
This is a UI metric for confidence presentation — not a formal astrophysics rating.
what it might be made of (model-based)
If spectra is missing, these bars are browsing aids — not confirmed chemistry.
Mostly hydrogen & helium (gas giant envelope)

81% modeled
High clouds / haze (possible)

51% modeled
Carbon-bearing bands (possible)

20% modeled
These are presentation layers derived from planet class + irradiation band — not direct detections. Confirmed atmosphere claims require direct measurements (spectra).
Why scientists keep revisiting systems like this:

Scientists keep revisiting systems like this because each new instrument pass can tighten uncertainties: better timing improves the orbit, better spectra improves the star, and better follow‑up can confirm or refute competing solutions. Even when a planet is well‑established, refined stellar properties can shift the inferred planet size, temperature, and habitability context.

discovery timeline
a readable story of how this planet entered the catalog
2023
Discovery announced using astrometry data from the ESA Gaia satellite.
2023-09
Peer-reviewed publication date for the discovery/parameter set.
2023-10-24
Catalog row updated (parameters may change as analyses improve).
2026-02-01
Profile rendered from the current catalog snapshot.
sources
NASA Exoplanet Archive (row-level fields)
Method metadata and derived UI bands (model-only)
No spectral claims are made without spectra.
Transparency: This page is a plain-language summary built from published catalog values. If newer studies revise any numbers, this profile will evolve with them.
Sponsored: View offer
Back to blog