Project NSB

It began as an argument on a roof

Project NSB is a volunteer group with no office, no budget to speak of and about fifteen people who like standing outside at night.

Sky in this banner: 17.84 mag/arcsec², the first reading, Zisa, March 2024

How it started

In the winter of 2023–24 a few friends who observed together from a rooftop in Palermo’s Zisa district kept having the same argument. Was the sky getting worse, or were we just getting older? None of us could say.

In March 2024 we clubbed together for one pocket photometer and took a reading from that roof. It said 17.84. We had no idea whether that was good. So we went to Mondello and measured there, then up Monte Pellegrino, and by the summer we had a notebook, a growing list of places, and friends in other towns asking to borrow the meter.

NSB stands for Night Sky Brightness. We are not a research institute and don’t pretend to be. What we can offer is patience: the same measurement at the same spots, for as many years as we keep turning up.

Milestones

  1. First reading, from a roof in the Zisa, Palermo: 17.84.
  2. Three meters. All eight Palermo points are fixed, plus the first ones in Monreale, Cefalù and the Madonie. The protocol is written down.
  3. Volunteers in Catania and Ragusa join, in time for the first full winter season.
  4. Siracusa and Trapani join. Protocol version 2 and the twice-yearly meter comparison begin.
  5. First points outside Sicily, in Reggio Calabria, Cosenza and Matera. 27 fixed points in all.
  6. Erice becomes the 28th point.
  7. The summer season closes, taking the total to 612 sessions and 3,060 readings.

Who does what

Four of us keep things running. Everyone else measures, and that is the part that matters.

  • Rosalia

    Coordinator, Palermo

    A retired physics teacher, and the owner of the roof. Keeps the rota, the meter log and the peace.

  • Nino

    Meters, Catania

    Repairs optical instruments for a living. Runs the side-by-side comparisons and looks after all twelve meters.

  • Marta

    Data, Cosenza

    A land surveyor. Checks every session before it reaches the tables, and writes most of the notes on this site.

  • Salvo

    Field training, Ragusa

    An agronomist who spends a lot of evenings on the road. Trains new volunteers in the south-east, and noticed the change at Ragusa Ibla before the numbers did.

Open data principles

A measurement nobody can check is only an opinion with decimals.

  • Every season is published

    Medians for every fixed point appear here within a month of a season closing.

  • The raw log is yours for the asking

    Plain text, one line per reading, discarded readings included. Write to hello@projectnsb.org and we’ll send it.

  • Awkward sessions stay on the record

    If we exclude a session, it stays in the log with the reason next to it.

  • Corrections are public

    If a figure turns out to be wrong, the note is corrected and says what changed and when.

  • The method comes with the data

    Every change to the protocol is dated, so a reading can always be matched to the rules it was taken under.

  • Free to reuse

    Use the figures for anything you like. A mention of Project NSB is welcome but not required.

Independence

We have no sponsors and no partners. Members paid for the meters themselves, nobody is paid to measure, and nobody pays us for a particular result.

Questions, corrections and offers of a good rooftop are welcome at hello@projectnsb.org.