---
title: "PSR B1257+12 d"
url: "https://spacecatalog.org/object/psr-b1257-12-d"
release: "DR1"
licence: "No licence stated; acknowledgement requested"
citation: "SpaceCatalog. PSR B1257+12 d [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/psr-b1257-12-d"
---

# PSR B1257+12 d

PSR B1257+12 d is a super-Earth in the constellation [Virgo](https://spacecatalog.org/constellation/virgo), 1957 ly from Earth. It orbits PSR B1257+12 at a mean distance of 0.46 AU. It has a mass of 3.90 M⊕ and a radius of 1.80 R⊕ · 11 481 km. It was discovered in 1992.

## At a glance

- **WHAT IT IS:** Super-Earth
- **HOW FAR:** 1957 ly — The light arriving now left it that long ago.
- **HOW BIG:** 1.80 R⊕ · 11 481 km — Its radius: half the width across.
- **WHERE TO LOOK:** [Virgo](https://spacecatalog.org/constellation/virgo) — The patch of sky it sits in, as seen from Earth.
- **ONE ORBIT TAKES:** 98.2 days — One trip round PSR B1257+12.

## Properties

| Quantity | Value |
| --- | --- |
| CLASS | Super-Earth |
| MASS | 3.90 M⊕ ±0.2 |
| RADIUS | 1.80 R⊕ · 11 481 km |
| DISTANCE FROM EARTH | 1957 ly ±326 — by NASA Exoplanet Archive sy\_dist (Konacki and Wolszczan 2003, 2003ApJ...591L.147K) |
| ORBITS | PSR B1257+12 |
| SEMI-MAJOR AXIS | 0.46 AU |
| CONSTELLATION | Virgo |
| RIGHT ASCENSION (J2000) | 13h 00m 03.6s |
| DECLINATION (J2000) | +12° 40′ 56.5″ |
| DISCOVERED | 1992 |

## Catalogue data

### WHAT KIND OF THING IT IS

What the object is in itself, rather than how it happens to look from here.

| Field | Value |
| --- | --- |
| Host star mass | 1.4 M☉ |

### THE ORBIT

The shape of the path, where the object sits on it, and the instant those figures were true of. An orbit is a fit to observations and drifts away from the real one either side of its epoch.

| Field | Value |
| --- | --- |
| Host star | PSR B1257+12 |
| Orbital period | 98.2114 days ±0.0002 |
| Eccentricity | 0.0264 ±0.0009 |
| Inclination | 47 ±3° |
| Argument of periastron | 108.3 ±0.5° |
| Periastron epoch | 2449767.0000 BJD |
| Stars in system | 1 |
| Planets in system | 3 |

### WHEN IT WAS FOUND

Who first saw it, from where, and by what method.

| Field | Value |
| --- | --- |
| Discovery method | Pulsar Timing |
| Discovered at | Arecibo Observatory |

## Also known as

- Exoplanet: PSR B1257+12 d

## Source

[NASA Exoplanet Archive (Planetary Systems Composite Parameters)](https://exoplanetarchive.ipac.caltech.edu/cgi-bin/TblView/nph-tblView?app=ExoTbls&config=PSCompPars) — No licence stated; acknowledgement requested

The producer asks: This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Cite Christiansen et al. (2025), Planetary Science Journal (doi:10.3847/PSJ/ade3c2), and the literature reference given with each value.

How this was made: https://spacecatalog.org/methods#source-exoplanet-archive

## Cite this page

SpaceCatalog. PSR B1257+12 d \[catalogue entry\]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/psr-b1257-12-d

```bibtex
@misc{spacecatalog_psr-b1257-12-d,
  author       = {{SpaceCatalog}},
  title        = {{PSR B1257+12 d}},
  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
  year         = {2026},
  url          = {https://spacecatalog.org/object/psr-b1257-12-d},
  note         = {Catalogue entry, data release DR1 (2026-08-21). Values from NASA Exoplanet Archive (Planetary Systems Composite Parameters).}
}
```

NASA Exoplanet Archive (Planetary Systems Composite Parameters) — No licence stated; acknowledgement requested

Acknowledgement the producer asks for: This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Cite Christiansen et al. (2025), Planetary Science Journal (doi:10.3847/PSJ/ade3c2), and the literature reference given with each value.

The page itself, with its pictures, the sky map and the observing tools: https://spacecatalog.org/object/psr-b1257-12-d