Merope
PlateThe archive. A photographic plate is a negative, so stars come out dark on pale stock — this is the thing an observer actually handled.Two ways of recording the same sky.SkyThe observation itself. The same stars, the way they looked before the glass.Two ways of recording the same sky.

Studio

Merope is a software studio of one. It builds a small number of things, keeps them running afterwards, and writes down what that takes. The catalogue says how alive each one is, on the scale a star’s brightness is measured on: lower is brighter, and six is the limit of what the eye can see unaided.

It is run by Ahmed Saed. If you want something built, or you want to argue with something written here, hello@merope.dev reaches a person.

01

The name

Merope is one of the seven Pleiades, and the sister most commonly identified as the Lost Pleiad — the one who married a mortal while her sisters consorted with gods, and hid her face afterwards. Both that attribution and the rival one for Electra are ancient, and neither is settled.

She is not the faintest of the seven, which is a thing popular astronomy writing repeats constantly. At magnitude 4.18 she is the 4th brightest of them. The title is mythological, not photometric: she is not the dimmest sister, she is the one with a story about dimming. For a studio of deliberately understated things, that is the more useful half.

What it lights up

The wisps around her — NGC 1435, found by Wilhelm Tempel in 1859 — were long assumed to be what remained of the cloud the Pleiades formed from. They are not. It is an unrelated interstellar cloud the cluster happens to be drifting through, and the nebulosity exists only because Merope’s light is falling on it.

The star is not the point. What it lights up is.

That is the whole idea. This site is the star; the projects are what it makes visible. A front door should not compete with the rooms.

Spare parts, real work

NASA Ames named a supercomputer Merope and then made the name literal: it was built out of the Intel Xeon 5400 (Harpertown) nodes from the original 2008 Pleiades, retired from Pleiades — the larger system named after the cluster Merope belongs to. 5120 cores, 61 teraflops, doing real science for eight years. Nothing has to be built with a budget to be worth using.

The plate

On 1885-11-16, Paul Henry and Prosper Henry photographed the Pleiades with the 13-inch refractor, Paris Observatory and recorded nebulosity nobody had seen through an eyepiece, including NGC 1432, the Maia Nebula. The camera saw what the eye could not, and a plate is a negative — which is why the light theme here is the archive rather than a concession to daylight.

02

Magnitude

The scale the catalogue borrows. It is inverted and logarithmic — lower is brighter — and six is the real limit of what an unaided eye can see, which makes it an honest way to say how alive a project is.

  • m1First magnitudeFlagship. Actively built, actively used.
  • m2Second magnitudeEstablished. Stable and maintained.
  • m3Third magnitudeLive. Released, still moving.
  • m4Fourth magnitudeWorking. Usable, rough in places.
  • m5Fifth magnitudeFaint. Early, public, unfinished.
  • m6Sixth magnitudeNaked-eye limit. An experiment.
  • m7TelescopicBelow the limit. Archived or private.
03

23 Tauri

The star itself, as a catalogue prints it. Every value is cited in docs/LORE.md.

Designation
23 Tau · HD 23480
Cluster
M45 — The Pleiades
Right ascension
03h 46m 19.59s
Declination
+23° 56′ 54.09″
Spectral type
B6IV(e)
Magnitude
4.18
Distance
460 ± 20 light years
Nebula
NGC 1435 · Tempel's Nebula · The Merope Nebula
Knot
IC 349 — Barnard's Merope Nebula, 3500 AU out