PSR B1257+12 SYSTEM / PLANETARY DOSSIER

PSR B1257+12 d

Phobetor: a pulsar planet whose interactions help reveal its true mass.

Planetary view ↗

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Artist’s impression of PSR B1257+12 d; appearance and diameter are unconfirmed
Pulsar planet · Phobetor

The outer partner in a resonant family.

Environment ↗

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ATMOSPHERE

Not measured

DIAMETER
Not measured
POSSIBILITY FOR LIFE
Not established
WITHOUT PROTECTION
No survivable environment established

Orbit ↗

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98.2114 Earth days

One year around PSR B1257+12

0.46 AU · semimajor axisSchematic · not to scale
Sources ↗

Mass comparison ↗

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DYNAMICAL MASS3.9 × Earth

± 0.2 Earth masses

Mutual gravitational perturbations constrain inclination and mass through pulsar timing.

Landscape ↗

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Hypothetical artist’s impression of Phobetor. An exposed rocky basin is one possible visual scenario. The terrain, composition, lighting and airless appearance are not observations of this planet. Any visible beam is a conceptual depiction of pulsar radiation.
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PSR B1257+12 D

Instrument detail

Artist’s impression of PSR B1257+12 d

Artist’s impression · appearance and diameter are unconfirmed.

Two naming systems, one world.

Phobetor is modern planet d. Older publications call it planet C. This entry uses the modern lower-case lettering throughout.

An orbit written into pulse arrivals.

The adopted timing solution gives a 98.2114-day orbit and semimajor axis of about 0.46 AU. The pulsar acts as a precise clock whose apparent arrival times shift as its position changes.

Mass does not reveal a landscape.

No surface has been photographed. Craters, cliffs and colors in these scenes are deliberately hypothetical. Without a measured radius, the mass alone cannot determine surface gravity or distinguish possible internal compositions.

The outer pair does not move independently.

Planets c and d have periods near a 3:2 ratio. Their small gravitational perturbations leave additional timing signatures, allowing a stronger mass inference than independent Keplerian orbits alone.

Size, mass and atmosphere

DIAMETER / EARTH

Not measured.

The radius has not been measured; the illustration does not establish its size.

SIZE UNKNOWN
DYNAMICAL MASS / EARTH
  • PSR B1257+12 d3.90 ± 0.20 M⊕
  • Earth · reference mass1.00 M⊕

Shared scale: 0–5 Earth masses. Mutual gravitational perturbations constrain inclination and mass through pulsar timing. Adopted values assume a 1.4-solar-mass pulsar. The cited timing solution resolves the minimum-mass ambiguity for the two larger planets.

ATMOSPHERE / COMPOSITION

Not measured

Pulsar timing reveals orbital motion, not the atmosphere. The rocky airless appearance is one imagined scenario; neither an atmosphere nor its absence is established by these pictures.

Habitability

NATURAL CONDITIONSNot established

The pulsar’s radiation and particle environment differs profoundly from sunlight. Planetary composition, shielding and atmospheric conditions remain unknown; an Earth-like mass cannot establish habitability.

HUMANS / WITHOUT PROTECTIONNo survivable environment established

No breathable air, safe pressure or measured surface climate is known. Assigning a survival time would be speculation.

DIAMETER
Unknown
ATMOSPHERE
Unconfirmed
SURFACE TEMPERATURE
Unknown
HOST
Millisecond pulsar

A year around PSR B1257+12

98.2114 Earth days

Semimajor axis: 0.46 AU. One astronomical unit is approximately the mean Earth–Sun distance.

The overview is a schematic: sizes, orbital shape and the planet’s position are illustrative. It does not show a measured eccentricity, the orbit’s orientation or a live position.

The adopted timing solution gives a 98.2114-day orbit and semimajor axis of about 0.46 AU. The pulsar acts as a precise clock whose apparent arrival times shift as its position changes.

Published research / NASA Exoplanet Archive · orbital measurements ↗
Hypothetical artist’s impression of Phobetor. An exposed rocky basin is one possible visual scenario. The terrain, composition, lighting and airless appearance are not observations of this planet. Any visible beam is a conceptual depiction of pulsar radiation.

An imagined crater floor

Hypothetical artist’s impression of Phobetor. An exposed rocky basin is one possible visual scenario. The terrain, composition, lighting and airless appearance are not observations of this planet. Any visible beam is a conceptual depiction of pulsar radiation.

Hypothetical artist’s impression of Phobetor. Cliffs and rubble provide an imagined close perspective. The terrain, composition, lighting and airless appearance are not observations of this planet. Any visible beam is a conceptual depiction of pulsar radiation.

A broken horizon

Hypothetical artist’s impression of Phobetor. Cliffs and rubble provide an imagined close perspective. The terrain, composition, lighting and airless appearance are not observations of this planet. Any visible beam is a conceptual depiction of pulsar radiation.

Hypothetical artist’s impression of Phobetor. A high view reveals a fictional cratered landscape. The terrain, composition, lighting and airless appearance are not observations of this planet. Any visible beam is a conceptual depiction of pulsar radiation.

Beyond the surface

Hypothetical artist’s impression of Phobetor. A high view reveals a fictional cratered landscape. The terrain, composition, lighting and airless appearance are not observations of this planet. Any visible beam is a conceptual depiction of pulsar radiation.

Planet and landscape images are hypothetical artistic interpretations.