← Back to dex
Rare pulsar 42 EP

J1757-1854

RA 269.2658° · Dec -18.9009° · pulsar

Loading sky survey…
🌌 View in 3D star map
Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 3 badges
42 pts · Rare
Rare 50 pts → Epic
  • Pulsar +22
  • Binary pulsar +12
  • Deeply embedded (high DM) +8
Total score 42

8 more points to reach Epic.

Badges

  • Pulsar · +22
  • Binary pulsar · +12
  • Deeply embedded (high DM) · +8

Trivia

Hard to believe

  • Surface speed. Its equator is moving at roughly 1% of the speed of light. Spin it much faster and it would tear itself apart.

Handle with care

  • Its gravity. Surface gravity is around 190 billion times Earth's. A fall of one metre would end at roughly a tenth of the speed of light.

What it actually is

  • What it is. The collapsed core of a star that exploded: about one and a half Suns of matter crushed into a ball the size of a city, held up only by the refusal of neutrons to be squeezed further.
  • Reading the fog. Its dispersion measure is 378 — a count of the free electrons in every column of space between here and there. Those electrons slow the low-frequency pulses more than the high ones, and that lag is how its distance is worked out.
  • It has a partner. It orbits a companion star, and because its pulses are such a precise clock the orbit can be traced to extraordinary accuracy. A binary pulsar is how gravitational waves were first proven to be real, decades before one was directly detected.

Find it in the sky

  • Southern sky. It rides the southern half of the sky — an easier target the further south you are.
  • Best time of year. It stands highest in the middle of the night around June — that's when to go looking.

Standing on it

  • Why we can see it. We only know about it because its beam happens to sweep across the Earth. Most of the galaxy's pulsars are pointing somewhere else and are invisible to us.

Properties

binary
yes
bsurf
7609285715
dm
378.111
name
J1757-1854
period ms
21.4972

Nearby objects

About J1757-1854

J1757-1854 is a rare pulsar. It spins once every 21.497 ms, has a dispersion measure of 378.11 pc cm⁻³ and carries a surface magnetic field around 7.61×10^9 G.

The collapsed core of a star that exploded: about one and a half Suns of matter crushed into a ball the size of a city, held up only by the refusal of neutrons to be squeezed further.

How to see it

Like any astronomical target, J1757-1854 is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.

Why J1757-1854 is a rare pulsar

J1757-1854 scores 42 points on Spacedle's rarity scale, which places it in the rare tier. Another 8 points would lift it into a rarer tier.

That score comes from 3 science badges — Pulsar, Binary pulsar and Deeply embedded (high DM) — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.