Lo Sky Quality Meter è uno strumento utile a misurare la luminosità del cielo. L’unità di misura utilizzata è la magnitudine per arcosecondo quadrato. Maggiore è la magnitudine rilevata, minore sarà l’inquinamento luminoso presente.
La magnitudine è una grandezza usata in astronomia per misurare la luminosità delle stelle (e degli altri oggetti celesti). Punti di riferimento sono:
Sole = –26,8
Luna piena = –12,6
stella Sirio = –1,5
limite delle stelle più deboli visibili ad occhio nudo = +6
L’arcosecondo quadrato è il quadratino di cielo di lato pari ad un arcosecondo di grado, cioè la 3600-ma parte di un grado (la Luna, ad esempio, ha un diametro di mezzo grado, quindi 1800 secondi d’arco).
All’Osservatorio abbiamo un sensore installato sulla cupola che rileva questa lettura ogni 5 minuti e la manda su un server dove viene elaborata e graficizzata. Il grafico sottostante viene aggiornato continuamente durante la notte e viene azzerato al crepuscolo quando iniziano le letture per il giorno successivo. Forti variazioni di lettura sono dovute o a luci accese nelle vicinanze o più verosimilmente a transito di nubi.
Letture medie e massime ultimi 30 giorni
Le letture vengono rese disponibili anche in formato Excel a partire dalle 7:45 ogni mattina, insieme ad altri parametri. Le colonne di questo file vanno lette così:
| MPSAS: | Magnitudine/arcsec2 |
| NELM: | Magnitudine stellare teorica visibile ad occhio nudo |
| Temp: | Temperatura del sensore |
| EncOffset: | Correzione alla magnitudine dovuta alla perdita di luminosità per la copertura del sensore |
| SolarAlt: | Altezza del sole in gradi decimali rispetto all’orizzonte |
| LunarAlt: | Altezza della luna in gradi decimali rispetto all’orizzonte |
| LunarPhase: | Fase lunare (0=luna nuova, 1: luna piena) |
Letture SQM delle ultime 24 ore
| DateTime | MPSAS | NELM | Temp | EncOffset | SolarAlt | LunarAlt | LunarPhase |
|---|---|---|---|---|---|---|---|
| 10/10/2026 04:39 PM | 7.60 | -6.05 | 24.80 | 0.10 | -1.01 | -5.38 | 0.00 |
| 10/10/2026 04:45 PM | 8.14 | -5.51 | 24.80 | 0.10 | -1.88 | -6.23 | 0.00 |
| 10/10/2026 04:50 PM | 9.04 | -4.62 | 24.40 | 0.10 | -2.75 | -7.08 | 0.00 |
| 10/10/2026 04:55 PM | 9.98 | -3.68 | 24.10 | 0.10 | -3.62 | -7.93 | 0.00 |
| 10/10/2026 05:00 PM | 10.97 | -2.70 | 23.80 | 0.10 | -4.49 | -8.78 | 0.00 |
| 10/10/2026 05:05 PM | 12.11 | -1.57 | 23.80 | 0.10 | -5.36 | -9.63 | 0.00 |
| 10/10/2026 05:10 PM | 13.28 | -0.42 | 23.50 | 0.10 | -6.23 | -10.49 | 0.00 |
| 10/10/2026 05:14 PM | 14.48 | 0.75 | 23.50 | 0.10 | -7.11 | -11.34 | 0.00 |
| 10/10/2026 05:20 PM | 15.63 | 1.84 | 23.20 | 0.10 | -7.98 | -12.20 | 0.00 |
| 10/10/2026 05:25 PM | 16.60 | 2.74 | 23.20 | 0.10 | -8.86 | -13.06 | 0.00 |
| 10/10/2026 05:29 PM | 17.46 | 3.51 | 23.20 | 0.10 | -9.73 | -13.91 | 0.00 |
| 10/10/2026 05:35 PM | 18.05 | 4.01 | 22.80 | 0.10 | -10.61 | -14.77 | 0.00 |
| 10/10/2026 05:39 PM | 18.53 | 4.40 | 22.80 | 0.10 | -11.48 | -15.63 | 0.00 |
| 10/10/2026 05:45 PM | 18.91 | 4.70 | 22.50 | 0.10 | -12.36 | -16.49 | 0.00 |
| 10/10/2026 05:50 PM | 19.18 | 4.91 | 22.50 | 0.10 | -13.23 | -17.34 | 0.00 |
| 10/10/2026 05:55 PM | 19.41 | 5.08 | 22.20 | 0.10 | -14.10 | -18.20 | 0.00 |
| 10/10/2026 06:00 PM | 19.55 | 5.18 | 22.20 | 0.10 | -14.97 | -19.06 | 0.00 |
| 10/10/2026 06:05 PM | 19.63 | 5.24 | 21.90 | 0.10 | -15.85 | -19.91 | 0.00 |
| 10/10/2026 06:10 PM | 19.69 | 5.28 | 21.50 | 0.10 | -16.71 | -20.77 | 0.00 |
| 10/10/2026 06:15 PM | 19.74 | 5.32 | 21.50 | 0.10 | -17.58 | -21.62 | 0.00 |
| 10/10/2026 06:20 PM | 19.69 | 5.28 | 21.50 | 0.10 | -18.45 | -22.47 | 0.00 |
| 10/10/2026 06:25 PM | 19.60 | 5.22 | 21.20 | 0.10 | -19.31 | -23.32 | 0.00 |
| 10/10/2026 06:29 PM | 19.61 | 5.22 | 21.20 | 0.10 | -20.17 | -24.17 | 0.00 |
| 10/10/2026 06:35 PM | 19.78 | 5.34 | 21.20 | 0.10 | -21.03 | -25.01 | 0.00 |
| 10/10/2026 06:39 PM | 19.84 | 5.39 | 20.90 | 0.10 | -21.88 | -25.85 | 0.00 |
| 10/10/2026 06:44 PM | 19.92 | 5.44 | 20.90 | 0.10 | -22.73 | -26.70 | 0.00 |
| 10/10/2026 06:50 PM | 19.87 | 5.41 | 20.60 | 0.10 | -23.58 | -27.54 | 0.00 |
| 10/10/2026 06:54 PM | 19.93 | 5.45 | 20.60 | 0.10 | -24.42 | -28.37 | 0.00 |
| 10/10/2026 07:00 PM | 19.98 | 5.48 | 20.60 | 0.10 | -25.26 | -29.20 | 0.00 |
| 10/10/2026 07:05 PM | 19.98 | 5.48 | 20.60 | 0.10 | -26.09 | -30.03 | 0.00 |
| 10/10/2026 07:09 PM | 20.00 | 5.49 | 20.30 | 0.10 | -26.92 | -30.86 | 0.00 |
| 10/10/2026 07:15 PM | 19.92 | 5.44 | 20.30 | 0.10 | -27.75 | -31.68 | 0.00 |
| 10/10/2026 07:20 PM | 19.88 | 5.41 | 20.30 | 0.10 | -28.57 | -32.49 | 0.00 |
| 10/10/2026 07:25 PM | 20.03 | 5.51 | 19.90 | 0.10 | -29.38 | -33.31 | 0.00 |
| 10/10/2026 07:30 PM | 19.98 | 5.48 | 19.90 | 0.10 | -30.19 | -34.11 | 0.00 |
| 10/10/2026 07:35 PM | 20.09 | 5.55 | 19.90 | 0.10 | -30.99 | -34.91 | 0.00 |
| 10/10/2026 07:40 PM | 20.21 | 5.63 | 19.90 | 0.10 | -31.78 | -35.71 | 0.00 |
| 10/10/2026 07:44 PM | 20.17 | 5.61 | 19.90 | 0.10 | -32.56 | -36.50 | 0.00 |
| 10/10/2026 07:50 PM | 20.26 | 5.67 | 19.60 | 0.10 | -33.34 | -37.28 | 0.00 |
| 10/10/2026 07:55 PM | 20.39 | 5.75 | 19.60 | 0.10 | -34.11 | -38.06 | 0.00 |
| 10/10/2026 07:59 PM | 20.38 | 5.74 | 19.60 | 0.10 | -34.87 | -38.83 | 0.00 |
| 10/10/2026 08:05 PM | 20.34 | 5.72 | 19.30 | 0.10 | -35.63 | -39.59 | 0.00 |
| 10/10/2026 08:09 PM | 20.48 | 5.81 | 19.30 | 0.10 | -36.37 | -40.35 | 0.00 |
| 10/10/2026 08:15 PM | 20.52 | 5.83 | 19.30 | 0.10 | -37.10 | -41.09 | 0.00 |
| 10/10/2026 08:19 PM | 20.54 | 5.84 | 19.30 | 0.10 | -37.82 | -41.83 | 0.00 |
| 10/10/2026 08:24 PM | 20.57 | 5.86 | 19.30 | 0.10 | -38.53 | -42.56 | 0.00 |
| 10/10/2026 08:30 PM | 20.55 | 5.85 | 19.00 | 0.10 | -39.23 | -43.28 | 0.00 |
| 10/10/2026 08:35 PM | 20.54 | 5.84 | 19.00 | 0.10 | -39.91 | -43.99 | 0.00 |
| 10/10/2026 08:40 PM | 20.60 | 5.88 | 19.00 | 0.10 | -40.58 | -44.68 | 0.00 |
| 10/10/2026 08:45 PM | 20.58 | 5.87 | 19.00 | 0.10 | -41.24 | -45.37 | 0.00 |
| 10/10/2026 08:50 PM | 20.64 | 5.90 | 18.60 | 0.10 | -41.89 | -46.04 | 0.00 |
| 10/10/2026 08:55 PM | 20.68 | 5.93 | 18.60 | 0.10 | -42.52 | -46.70 | 0.00 |
| 10/10/2026 09:00 PM | 20.62 | 5.89 | 18.60 | 0.10 | -43.13 | -47.35 | 0.00 |
| 10/10/2026 09:05 PM | 20.68 | 5.93 | 18.60 | 0.10 | -43.73 | -47.98 | 0.00 |
| 10/10/2026 09:10 PM | 20.69 | 5.93 | 18.30 | 0.10 | -44.31 | -48.60 | 0.00 |
| 10/10/2026 09:15 PM | 20.64 | 5.90 | 18.30 | 0.10 | -44.87 | -49.20 | 0.00 |
| 10/10/2026 09:20 PM | 20.65 | 5.91 | 18.30 | 0.10 | -45.41 | -49.79 | 0.00 |
| 10/10/2026 09:24 PM | 20.67 | 5.92 | 18.30 | 0.10 | -45.94 | -50.36 | 0.00 |
| 10/10/2026 09:30 PM | 20.54 | 5.84 | 18.30 | 0.10 | -46.44 | -50.91 | 0.00 |
| 10/10/2026 09:34 PM | 20.68 | 5.93 | 18.00 | 0.10 | -46.93 | -51.44 | 0.00 |
| 10/10/2026 09:40 PM | 20.75 | 5.97 | 18.30 | 0.10 | -47.39 | -51.96 | 0.00 |
| 10/10/2026 09:44 PM | 20.72 | 5.95 | 18.00 | 0.10 | -47.83 | -52.45 | 0.00 |
| 10/10/2026 09:50 PM | 20.74 | 5.96 | 18.00 | 0.10 | -48.25 | -52.92 | 0.00 |
| 10/10/2026 09:55 PM | 20.77 | 5.98 | 18.00 | 0.10 | -48.64 | -53.37 | 0.00 |
| 10/10/2026 09:59 PM | 20.80 | 6.00 | 18.00 | 0.10 | -49.01 | -53.80 | 0.00 |
| 10/10/2026 10:05 PM | 20.76 | 5.98 | 18.00 | 0.10 | -49.35 | -54.20 | 0.00 |
| 10/10/2026 10:09 PM | 20.74 | 5.96 | 18.00 | 0.10 | -49.67 | -54.58 | 0.00 |
| 10/10/2026 10:15 PM | 20.75 | 5.97 | 18.00 | 0.10 | -49.96 | -54.93 | 0.00 |
| 10/10/2026 10:19 PM | 20.77 | 5.98 | 18.00 | 0.10 | -50.22 | -55.26 | 0.00 |
| 10/10/2026 10:25 PM | 20.80 | 6.00 | 18.00 | 0.10 | -50.46 | -55.56 | 0.00 |
| 10/10/2026 10:29 PM | 20.81 | 6.01 | 17.70 | 0.10 | -50.67 | -55.83 | 0.00 |
| 10/10/2026 10:35 PM | 20.81 | 6.01 | 17.70 | 0.10 | -50.84 | -56.08 | 0.00 |
| 10/10/2026 10:39 PM | 20.82 | 6.01 | 17.70 | 0.10 | -50.99 | -56.29 | 0.00 |
| 10/10/2026 10:44 PM | 20.81 | 6.01 | 17.70 | 0.10 | -51.11 | -56.48 | 0.00 |
| 10/10/2026 10:50 PM | 20.80 | 6.00 | 17.70 | 0.10 | -51.20 | -56.63 | 0.00 |
| 10/10/2026 10:55 PM | 20.83 | 6.02 | 17.70 | 0.10 | -51.26 | -56.76 | 0.00 |
| 10/10/2026 11:00 PM | 20.85 | 6.03 | 17.70 | 0.10 | -51.29 | -56.85 | 0.00 |
| 10/10/2026 11:05 PM | 20.84 | 6.02 | 17.70 | 0.10 | -51.29 | -56.92 | 0.00 |
| 10/10/2026 11:10 PM | 20.85 | 6.03 | 17.70 | 0.10 | -51.26 | -56.95 | 0.00 |
| 10/10/2026 11:15 PM | 20.85 | 6.03 | 17.70 | 0.10 | -51.20 | -56.95 | 0.00 |
| 10/10/2026 11:20 PM | 20.85 | 6.03 | 17.70 | 0.10 | -51.11 | -56.92 | 0.00 |
| 10/10/2026 11:24 PM | 20.85 | 6.03 | 17.70 | 0.10 | -50.99 | -56.86 | 0.00 |
| 10/10/2026 11:30 PM | 20.85 | 6.03 | 17.70 | 0.10 | -50.84 | -56.77 | 0.00 |
| 10/10/2026 11:35 PM | 20.85 | 6.03 | 17.70 | 0.10 | -50.66 | -56.64 | 0.00 |
| 10/10/2026 11:40 PM | 20.85 | 6.03 | 17.40 | 0.10 | -50.45 | -56.49 | 0.00 |
| 10/10/2026 11:45 PM | 20.84 | 6.02 | 17.40 | 0.10 | -50.21 | -56.31 | 0.00 |
| 10/10/2026 11:50 PM | 20.84 | 6.02 | 17.40 | 0.10 | -49.95 | -56.10 | 0.00 |
| 10/10/2026 11:55 PM | 20.83 | 6.02 | 17.40 | 0.10 | -49.66 | -55.85 | 0.00 |
| 11/10/2026 12:00 AM | 20.83 | 6.02 | 17.40 | 0.10 | -49.34 | -55.59 | 0.00 |
| 11/10/2026 12:04 AM | 20.83 | 6.02 | 17.40 | 0.10 | -49.00 | -55.29 | 0.00 |
| 11/10/2026 12:10 AM | 20.83 | 6.02 | 17.40 | 0.10 | -48.63 | -54.97 | 0.00 |
| 11/10/2026 12:15 AM | 20.83 | 6.02 | 17.40 | 0.10 | -48.23 | -54.62 | 0.00 |
| 11/10/2026 12:19 AM | 20.83 | 6.02 | 17.40 | 0.10 | -47.82 | -54.24 | 0.00 |
| 11/10/2026 12:24 AM | 20.83 | 6.02 | 17.40 | 0.10 | -47.38 | -53.84 | 0.00 |
| 11/10/2026 12:30 AM | 20.84 | 6.02 | 17.40 | 0.10 | -46.91 | -53.42 | 0.00 |
| 11/10/2026 12:34 AM | 20.84 | 6.02 | 17.40 | 0.10 | -46.43 | -52.98 | 0.00 |
| 11/10/2026 12:39 AM | 20.85 | 6.03 | 17.40 | 0.10 | -45.92 | -52.51 | 0.00 |
| 11/10/2026 12:45 AM | 20.84 | 6.02 | 17.40 | 0.10 | -45.40 | -52.02 | 0.00 |
| 11/10/2026 12:50 AM | 20.85 | 6.03 | 17.40 | 0.10 | -44.85 | -51.51 | 0.00 |
| 11/10/2026 12:55 AM | 20.85 | 6.03 | 17.40 | 0.10 | -44.29 | -50.99 | 0.00 |
| 11/10/2026 01:00 AM | 20.83 | 6.02 | 17.40 | 0.10 | -43.71 | -50.44 | 0.00 |
| 11/10/2026 01:05 AM | 20.84 | 6.02 | 17.40 | 0.10 | -43.11 | -49.88 | 0.00 |
| 11/10/2026 01:10 AM | 20.85 | 6.03 | 17.40 | 0.10 | -42.50 | -49.30 | 0.00 |
| 11/10/2026 01:15 AM | 20.85 | 6.03 | 17.40 | 0.10 | -41.87 | -48.71 | 0.00 |
| 11/10/2026 01:20 AM | 20.86 | 6.04 | 17.40 | 0.10 | -41.22 | -48.10 | 0.00 |
| 11/10/2026 01:25 AM | 20.87 | 6.04 | 17.40 | 0.10 | -40.57 | -47.47 | 0.00 |
| 11/10/2026 01:30 AM | 20.87 | 6.04 | 17.40 | 0.10 | -39.89 | -46.83 | 0.00 |
| 11/10/2026 01:34 AM | 20.87 | 6.04 | 17.00 | 0.10 | -39.21 | -46.19 | 0.00 |
| 11/10/2026 01:40 AM | 20.88 | 6.05 | 17.00 | 0.10 | -38.51 | -45.52 | 0.00 |
| 11/10/2026 01:44 AM | 20.87 | 6.04 | 17.00 | 0.10 | -37.80 | -44.85 | 0.00 |
| 11/10/2026 01:49 AM | 20.89 | 6.05 | 17.00 | 0.10 | -37.08 | -44.16 | 0.00 |
| 11/10/2026 01:55 AM | 20.89 | 6.05 | 17.00 | 0.10 | -36.35 | -43.46 | 0.00 |
| 11/10/2026 02:00 AM | 20.89 | 6.05 | 17.00 | 0.10 | -35.61 | -42.75 | 0.00 |
| 11/10/2026 02:04 AM | 20.89 | 6.05 | 17.00 | 0.10 | -34.86 | -42.04 | 0.00 |
| 11/10/2026 02:10 AM | 20.87 | 6.04 | 17.00 | 0.10 | -34.10 | -41.31 | 0.00 |
| 11/10/2026 02:15 AM | 20.89 | 6.05 | 17.00 | 0.10 | -33.33 | -40.58 | 0.00 |
| 11/10/2026 02:20 AM | 20.89 | 6.05 | 17.00 | 0.10 | -32.55 | -39.84 | 0.00 |
| 11/10/2026 02:25 AM | 20.89 | 6.05 | 17.00 | 0.10 | -31.76 | -39.09 | 0.00 |
| 11/10/2026 02:30 AM | 20.89 | 6.05 | 17.00 | 0.10 | -30.97 | -38.33 | 0.00 |
| 11/10/2026 02:35 AM | 20.89 | 6.05 | 17.00 | 0.10 | -30.17 | -37.57 | 0.00 |
| 11/10/2026 02:40 AM | 20.89 | 6.05 | 16.70 | 0.10 | -29.37 | -36.80 | 0.00 |
| 11/10/2026 02:45 AM | 20.87 | 6.04 | 17.00 | 0.10 | -28.56 | -36.02 | 0.00 |
| 11/10/2026 02:49 AM | 20.88 | 6.05 | 17.00 | 0.10 | -27.74 | -35.24 | 0.00 |
| 11/10/2026 02:55 AM | 20.88 | 6.05 | 17.00 | 0.10 | -26.91 | -34.46 | 0.00 |
| 11/10/2026 02:59 AM | 20.88 | 6.05 | 17.00 | 0.10 | -26.09 | -33.67 | 0.00 |
| 11/10/2026 03:05 AM | 20.89 | 6.05 | 17.00 | 0.10 | -25.25 | -32.87 | 0.00 |
| 11/10/2026 03:09 AM | 20.89 | 6.05 | 17.00 | 0.10 | -24.42 | -32.07 | 0.00 |
| 11/10/2026 03:14 AM | 20.88 | 6.05 | 17.00 | 0.10 | -23.57 | -31.27 | 0.00 |
| 11/10/2026 03:20 AM | 20.88 | 6.05 | 17.00 | 0.10 | -22.73 | -30.46 | 0.00 |
| 11/10/2026 03:25 AM | 20.89 | 6.05 | 17.00 | 0.10 | -21.87 | -29.65 | 0.00 |
| 11/10/2026 03:29 AM | 20.88 | 6.05 | 17.00 | 0.10 | -21.02 | -28.84 | 0.00 |
| 11/10/2026 03:35 AM | 20.88 | 6.05 | 16.70 | 0.10 | -20.17 | -28.02 | 0.00 |
| 11/10/2026 03:39 AM | 20.88 | 6.05 | 16.70 | 0.10 | -19.31 | -27.21 | 0.00 |
| 11/10/2026 03:45 AM | 20.87 | 6.04 | 16.70 | 0.10 | -18.45 | -26.39 | 0.00 |
| 11/10/2026 03:50 AM | 20.86 | 6.04 | 16.70 | 0.10 | -17.58 | -25.57 | 0.01 |
| 11/10/2026 03:55 AM | 20.85 | 6.03 | 16.70 | 0.10 | -16.72 | -24.74 | 0.01 |
| 11/10/2026 04:00 AM | 20.82 | 6.01 | 16.70 | 0.10 | -15.85 | -23.92 | 0.01 |
| 11/10/2026 04:05 AM | 20.76 | 5.98 | 16.40 | 0.10 | -14.98 | -23.09 | 0.01 |
| 11/10/2026 04:09 AM | 20.63 | 5.90 | 16.40 | 0.10 | -14.12 | -22.27 | 0.01 |
| 11/10/2026 04:15 AM | 20.37 | 5.74 | 16.40 | 0.10 | -13.24 | -21.43 | 0.01 |
| 11/10/2026 04:19 AM | 19.95 | 5.46 | 16.40 | 0.10 | -12.37 | -20.61 | 0.01 |
| 11/10/2026 04:24 AM | 19.36 | 5.04 | 16.40 | 0.10 | -11.50 | -19.78 | 0.01 |
| 11/10/2026 04:29 AM | 18.66 | 4.51 | 16.40 | 0.10 | -10.62 | -18.95 | 0.01 |
| 11/10/2026 04:35 AM | 17.89 | 3.88 | 16.40 | 0.10 | -9.75 | -18.12 | 0.01 |
| 11/10/2026 04:40 AM | 16.73 | 2.86 | 16.40 | 0.10 | -8.88 | -17.29 | 0.01 |
| 11/10/2026 04:45 AM | 15.84 | 2.04 | 16.40 | 0.10 | -8.00 | -16.46 | 0.01 |
| 11/10/2026 04:50 AM | 14.78 | 1.04 | 16.40 | 0.10 | -7.13 | -15.63 | 0.01 |
| 11/10/2026 04:55 AM | 13.70 | -0.01 | 16.40 | 0.10 | -6.26 | -14.80 | 0.01 |
| DateTime | MPSAS | NELM | Temp | EncOffset | SolarAlt | LunarAlt | LunarPhase |