HIP 78530 b

HIP 78530 b — Exoplanet profile
Exoplanet profile

HIP 78530 b

Host star: HIP 78530 • Discovery: 2010 • Method: Imaging
confirmed planet • updated: 2015-04-01
confirmed planet direct imaging modeled atmosphere derived

HIP 78530 b orbits the star HIP 78530, a hot blue-white star. Scientists found it using direct imaging — taking a picture of the planet itself — with the Gemini Observatory in 2010.

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
446.0 ly
Star temp
10500 K
Mass
23.0 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 object is very massive — about 23 times the mass of Jupiter — and orbits at a distance of roughly 740 times Earth’s distance from the Sun. Because it was found by imaging, we don’t yet know its full orbit or how elliptical it is. Its estimated temperature is about 2700°C, which is very hot, likely due to its young age and internal heat.

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
740.00 AU
Meaning: average distance from the star (Earth = 1 AU).
Eccentricity
—
Meaning: how oval the orbit is (0 is a circle).
Host star type
B9 V
A spectral label that summarizes temperature and color.
Host star radius
—
Bigger stars can change how “hot” a planet’s orbit feels.
Metallicity
—
Meaning: how “heavy-element rich” the star is vs the Sun.
Distance
446.0 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 78530 b was first reported in 2010 using the Imaging method. The discovery is linked to observations from Gemini Observatory.

Direct imaging tries to separate faint planetary light from the glare of the host star. It works best for young, warm planets far from their stars.

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

The catalog lists a semi-major axis near 740.000 AU.

Eccentricity is not provided here; many catalogs omit it when the solution is underconstrained.

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 23.0 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 78530 b orbits HIP 78530. The star is classified as B9 V, which is a shorthand for temperature and color.

A temperature near 10500 K places it on the hotter side of the main sequence. The system is about 446.0 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, orbital period, eccentricity. 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: — d • e: — • a: 740.00 AU
orbit stability
signal-to-noise proxy
59% 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)

82% modeled
High clouds / haze (possible)

10% modeled
Carbon-bearing bands (possible)

70% 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
2010
First detected by direct imaging using the Gemini Observatory.
2015-03
Peer-reviewed publication date for the discovery/parameter set.
2015-04-01
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