Week 4: The clocks of pulsars

Use periodic radio pulses to distinguish audification from musical quantisation.

Week 04 · Periodicity

16 August 2027

How can timing reveal a pulsar without turning its regularity into a beat fiction?

Data object
folded pulsar pulse profile
Lecture deckOpen the taught visual narrative

The question

Pulsars produce regular radio pulses, but the recording available to us is already sampled, filtered and often folded over many rotations. We inspect a pulse profile before deciding whether to audify amplitude, trigger an event or compress time.

Signal chain

Radio intensity over time → remove baseline → identify period → fold repeated pulses → map amplitude to loudness. Tempo grids are not part of the source unless the designer adds them.

The ATNF Pulsar Catalogue provides published pulsar parameters and makes a useful provenance starting point for the first signal study.

Observation guide 04

Periodicity

Use this page before the slides, then return to the checkpoint after the lab.

After this week, you can

  1. Read a pulsar period and pulse profile without treating either as music.
  2. Explain what folding preserves and what repeated averaging removes.
  3. Compare raw event timing with a folded representation.

Inspectable teaching model

relative radio intensity
Synthetic intensity bins across two repeated rotations. Values are a teaching model, not an astronomical observation.

Worked notebook

Fold repeated pulses

Synthetic intensity bins across two repeated rotations.

  1. Use five bins as the stated rotation period.
  2. Align the second group of five bins beneath the first.
  3. Average corresponding phase bins to create one folded profile.
  4. Compare the folded peak with the two original pulse heights.

What the method supportsFolding strengthens a stable phase pattern and suppresses differences between rotations. The folded profile cannot show which individual pulse was stronger.

CheckpointWhy would adding a steady drum grid to irregular pulse arrivals create a stronger claim than the source supports?Reveal the reasoning

The grid introduces regular musical timing that was not measured.

A published period supports phase alignment over many rotations. It does not make every detected pulse identical or every arrival free of noise. A drum grid can hide those distinctions.

Read from the source

ATNF Pulsar Catalogue documentation by CSIRO Australia Telescope National Facility

Check parameter definitions, units and catalogue provenance before selecting a pulsar.

Where this goes next

The raw and folded pair becomes the central evidence in the Pulsar Signal Study.

Teaching team