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 |
|---|---|---|---|---|---|---|---|
| 08/10/2026 04:44 PM | 8.16 | -5.49 | 23.80 | 0.10 | -1.24 | -12.51 | 0.04 |
| 08/10/2026 04:50 PM | 8.82 | -4.84 | 23.20 | 0.10 | -2.11 | -13.35 | 0.04 |
| 08/10/2026 04:54 PM | 9.58 | -4.08 | 23.20 | 0.10 | -2.98 | -14.17 | 0.04 |
| 08/10/2026 05:00 PM | 10.52 | -3.14 | 22.80 | 0.10 | -3.85 | -15.00 | 0.04 |
| 08/10/2026 05:04 PM | 11.62 | -2.05 | 22.50 | 0.10 | -4.72 | -15.82 | 0.04 |
| 08/10/2026 05:10 PM | 12.76 | -0.93 | 22.20 | 0.10 | -5.60 | -16.64 | 0.04 |
| 08/10/2026 05:14 PM | 13.72 | 0.01 | 22.20 | 0.10 | -6.47 | -17.44 | 0.04 |
| 08/10/2026 05:20 PM | 14.71 | 0.97 | 22.20 | 0.10 | -7.35 | -18.25 | 0.04 |
| 08/10/2026 05:24 PM | 15.67 | 1.88 | 21.90 | 0.10 | -8.22 | -19.05 | 0.04 |
| 08/10/2026 05:30 PM | 16.69 | 2.82 | 21.90 | 0.10 | -9.10 | -19.85 | 0.04 |
| 08/10/2026 05:35 PM | 17.84 | 3.83 | 21.90 | 0.10 | -9.97 | -20.64 | 0.04 |
| 08/10/2026 05:40 PM | 18.67 | 4.52 | 21.90 | 0.10 | -10.85 | -21.43 | 0.04 |
| 08/10/2026 05:45 PM | 19.13 | 4.87 | 21.90 | 0.10 | -11.72 | -22.20 | 0.04 |
| 08/10/2026 05:50 PM | 19.31 | 5.01 | 21.50 | 0.10 | -12.60 | -22.97 | 0.04 |
| 08/10/2026 05:54 PM | 19.32 | 5.01 | 21.50 | 0.10 | -13.47 | -23.74 | 0.04 |
| 08/10/2026 06:00 PM | 19.79 | 5.35 | 21.50 | 0.10 | -14.34 | -24.50 | 0.04 |
| 08/10/2026 06:05 PM | 20.19 | 5.62 | 21.50 | 0.10 | -15.21 | -25.25 | 0.04 |
| 08/10/2026 06:10 PM | 20.03 | 5.51 | 21.50 | 0.10 | -16.08 | -25.99 | 0.04 |
| 08/10/2026 06:14 PM | 20.11 | 5.57 | 21.50 | 0.10 | -16.94 | -26.73 | 0.04 |
| 08/10/2026 06:20 PM | 20.00 | 5.49 | 21.50 | 0.10 | -17.81 | -27.46 | 0.04 |
| 08/10/2026 06:25 PM | 20.07 | 5.54 | 21.50 | 0.10 | -18.67 | -28.17 | 0.04 |
| 08/10/2026 06:30 PM | 19.93 | 5.45 | 21.50 | 0.10 | -19.53 | -28.88 | 0.04 |
| 08/10/2026 06:35 PM | 19.76 | 5.33 | 21.50 | 0.10 | -20.38 | -29.58 | 0.04 |
| 08/10/2026 06:39 PM | 20.17 | 5.61 | 21.50 | 0.10 | -21.23 | -30.27 | 0.04 |
| 08/10/2026 06:45 PM | 20.28 | 5.68 | 21.50 | 0.10 | -22.08 | -30.95 | 0.04 |
| 08/10/2026 06:50 PM | 20.53 | 5.84 | 21.50 | 0.10 | -22.93 | -31.62 | 0.04 |
| 08/10/2026 06:54 PM | 20.57 | 5.86 | 21.50 | 0.10 | -23.77 | -32.28 | 0.04 |
| 08/10/2026 07:00 PM | 20.61 | 5.89 | 21.50 | 0.10 | -24.61 | -32.92 | 0.04 |
| 08/10/2026 07:05 PM | 20.50 | 5.82 | 21.20 | 0.10 | -25.44 | -33.56 | 0.04 |
| 08/10/2026 07:09 PM | 20.14 | 5.59 | 21.20 | 0.10 | -26.27 | -34.18 | 0.04 |
| 08/10/2026 07:14 PM | 19.80 | 5.36 | 21.20 | 0.10 | -27.09 | -34.79 | 0.04 |
| 08/10/2026 07:20 PM | 19.66 | 5.26 | 21.20 | 0.10 | -27.91 | -35.39 | 0.04 |
| 08/10/2026 07:24 PM | 20.45 | 5.79 | 21.20 | 0.10 | -28.72 | -35.97 | 0.04 |
| 08/10/2026 07:30 PM | 20.65 | 5.91 | 20.90 | 0.10 | -29.52 | -36.54 | 0.04 |
| 08/10/2026 07:35 PM | 20.65 | 5.91 | 20.90 | 0.10 | -30.32 | -37.09 | 0.04 |
| 08/10/2026 07:40 PM | 20.54 | 5.84 | 20.90 | 0.10 | -31.11 | -37.63 | 0.04 |
| 08/10/2026 07:45 PM | 20.25 | 5.66 | 20.90 | 0.10 | -31.89 | -38.15 | 0.04 |
| 08/10/2026 07:50 PM | 20.16 | 5.60 | 20.60 | 0.10 | -32.66 | -38.66 | 0.04 |
| 08/10/2026 07:54 PM | 20.53 | 5.84 | 20.60 | 0.10 | -33.43 | -39.15 | 0.04 |
| 08/10/2026 08:00 PM | 20.52 | 5.83 | 20.60 | 0.10 | -34.19 | -39.62 | 0.04 |
| 08/10/2026 08:05 PM | 20.32 | 5.70 | 20.60 | 0.10 | -34.94 | -40.07 | 0.04 |
| 08/10/2026 08:10 PM | 20.37 | 5.74 | 20.60 | 0.10 | -35.68 | -40.51 | 0.04 |
| 08/10/2026 08:14 PM | 19.72 | 5.30 | 20.30 | 0.10 | -36.40 | -40.93 | 0.04 |
| 08/10/2026 08:20 PM | 19.70 | 5.29 | 20.30 | 0.10 | -37.12 | -41.33 | 0.04 |
| 08/10/2026 08:24 PM | 20.05 | 5.53 | 20.30 | 0.10 | -37.83 | -41.71 | 0.04 |
| 08/10/2026 08:30 PM | 20.02 | 5.51 | 20.60 | 0.10 | -38.52 | -42.06 | 0.04 |
| 08/10/2026 08:35 PM | 20.16 | 5.60 | 20.60 | 0.10 | -39.20 | -42.40 | 0.04 |
| 08/10/2026 08:40 PM | 19.98 | 5.48 | 20.60 | 0.10 | -39.87 | -42.72 | 0.04 |
| 08/10/2026 08:45 PM | 19.73 | 5.31 | 20.90 | 0.10 | -40.53 | -43.01 | 0.04 |
| 08/10/2026 08:50 PM | 20.08 | 5.55 | 20.90 | 0.10 | -41.17 | -43.29 | 0.04 |
| 08/10/2026 08:54 PM | 19.95 | 5.46 | 20.90 | 0.10 | -41.79 | -43.53 | 0.04 |
| 08/10/2026 08:59 PM | 19.82 | 5.37 | 21.20 | 0.10 | -42.40 | -43.76 | 0.04 |
| 08/10/2026 09:05 PM | 20.04 | 5.52 | 21.20 | 0.10 | -43.00 | -43.97 | 0.04 |
| 08/10/2026 09:10 PM | 20.04 | 5.52 | 21.20 | 0.10 | -43.57 | -44.15 | 0.04 |
| 08/10/2026 09:14 PM | 20.19 | 5.62 | 21.20 | 0.10 | -44.13 | -44.30 | 0.04 |
| 08/10/2026 09:19 PM | 20.83 | 6.02 | 21.50 | 0.10 | -44.67 | -44.44 | 0.04 |
| 08/10/2026 09:25 PM | 20.49 | 5.81 | 21.50 | 0.10 | -45.19 | -44.55 | 0.03 |
| 08/10/2026 09:30 PM | 19.95 | 5.46 | 21.20 | 0.10 | -45.69 | -44.63 | 0.03 |
| 08/10/2026 09:35 PM | 19.97 | 5.47 | 21.20 | 0.10 | -46.17 | -44.69 | 0.03 |
| 08/10/2026 09:40 PM | 20.53 | 5.84 | 21.50 | 0.10 | -46.63 | -44.73 | 0.03 |
| 08/10/2026 09:45 PM | 20.14 | 5.59 | 21.50 | 0.10 | -47.07 | -44.74 | 0.03 |
| 08/10/2026 09:50 PM | 19.91 | 5.43 | 21.50 | 0.10 | -47.49 | -44.72 | 0.03 |
| 08/10/2026 09:55 PM | 20.08 | 5.55 | 21.50 | 0.10 | -47.88 | -44.68 | 0.03 |
| 08/10/2026 09:59 PM | 20.55 | 5.85 | 21.50 | 0.10 | -48.24 | -44.62 | 0.03 |
| 08/10/2026 10:05 PM | 20.65 | 5.91 | 21.50 | 0.10 | -48.58 | -44.53 | 0.03 |
| 08/10/2026 10:09 PM | 20.85 | 6.03 | 21.50 | 0.10 | -48.90 | -44.42 | 0.03 |
| 08/10/2026 10:15 PM | 21.00 | 6.12 | 21.50 | 0.10 | -49.19 | -44.29 | 0.03 |
| 08/10/2026 10:20 PM | 20.84 | 6.02 | 21.20 | 0.10 | -49.45 | -44.13 | 0.03 |
| 08/10/2026 10:25 PM | 20.88 | 6.05 | 21.20 | 0.10 | -49.69 | -43.94 | 0.03 |
| 08/10/2026 10:30 PM | 20.60 | 5.88 | 21.20 | 0.10 | -49.90 | -43.74 | 0.03 |
| 08/10/2026 10:34 PM | 20.85 | 6.03 | 21.20 | 0.10 | -50.07 | -43.51 | 0.03 |
| 08/10/2026 10:40 PM | 20.88 | 6.05 | 21.20 | 0.10 | -50.23 | -43.25 | 0.03 |
| 08/10/2026 10:44 PM | 20.55 | 5.85 | 21.20 | 0.10 | -50.35 | -42.98 | 0.03 |
| 08/10/2026 10:50 PM | 20.35 | 5.72 | 20.90 | 0.10 | -50.44 | -42.68 | 0.03 |
| 08/10/2026 10:55 PM | 20.37 | 5.74 | 20.90 | 0.10 | -50.50 | -42.36 | 0.03 |
| 08/10/2026 11:00 PM | 20.62 | 5.89 | 20.90 | 0.10 | -50.53 | -42.03 | 0.03 |
| 08/10/2026 11:05 PM | 20.47 | 5.80 | 20.90 | 0.10 | -50.54 | -41.67 | 0.03 |
| 08/10/2026 11:10 PM | 20.17 | 5.61 | 20.90 | 0.10 | -50.51 | -41.29 | 0.03 |
| 08/10/2026 11:15 PM | 20.09 | 5.55 | 20.90 | 0.10 | -50.45 | -40.89 | 0.03 |
| 08/10/2026 11:20 PM | 20.28 | 5.68 | 20.90 | 0.10 | -50.37 | -40.47 | 0.03 |
| 08/10/2026 11:25 PM | 20.63 | 5.90 | 21.20 | 0.10 | -50.25 | -40.04 | 0.03 |
| 08/10/2026 11:30 PM | 20.64 | 5.90 | 21.20 | 0.10 | -50.10 | -39.58 | 0.03 |
| 08/10/2026 11:35 PM | 20.31 | 5.70 | 20.90 | 0.10 | -49.93 | -39.11 | 0.03 |
| 08/10/2026 11:39 PM | 20.20 | 5.63 | 21.20 | 0.10 | -49.73 | -38.62 | 0.03 |
| 08/10/2026 11:45 PM | 20.00 | 5.49 | 21.20 | 0.10 | -49.50 | -38.12 | 0.03 |
| 08/10/2026 11:50 PM | 20.12 | 5.57 | 21.20 | 0.10 | -49.24 | -37.60 | 0.03 |
| 08/10/2026 11:55 PM | 20.37 | 5.74 | 21.20 | 0.10 | -48.96 | -37.06 | 0.03 |
| 09/10/2026 12:00 AM | 20.50 | 5.82 | 21.20 | 0.10 | -48.64 | -36.51 | 0.03 |
| 09/10/2026 12:05 AM | 20.49 | 5.81 | 21.20 | 0.10 | -48.31 | -35.95 | 0.03 |
| 09/10/2026 12:10 AM | 20.44 | 5.78 | 21.20 | 0.10 | -47.95 | -35.37 | 0.03 |
| 09/10/2026 12:14 AM | 20.54 | 5.84 | 21.20 | 0.10 | -47.56 | -34.78 | 0.03 |
| 09/10/2026 12:20 AM | 20.47 | 5.80 | 21.20 | 0.10 | -47.15 | -34.17 | 0.03 |
| 09/10/2026 12:25 AM | 20.57 | 5.86 | 21.20 | 0.10 | -46.72 | -33.56 | 0.03 |
| 09/10/2026 12:30 AM | 20.53 | 5.84 | 20.90 | 0.10 | -46.26 | -32.93 | 0.03 |
| 09/10/2026 12:34 AM | 20.37 | 5.74 | 20.90 | 0.10 | -45.78 | -32.29 | 0.03 |
| 09/10/2026 12:40 AM | 20.17 | 5.61 | 20.90 | 0.10 | -45.29 | -31.64 | 0.03 |
| 09/10/2026 12:45 AM | 20.24 | 5.65 | 20.90 | 0.10 | -44.77 | -30.98 | 0.03 |
| 09/10/2026 12:49 AM | 20.38 | 5.74 | 20.90 | 0.10 | -44.23 | -30.30 | 0.03 |
| 09/10/2026 12:55 AM | 20.20 | 5.63 | 20.90 | 0.10 | -43.68 | -29.62 | 0.03 |
| 09/10/2026 12:59 AM | 20.47 | 5.80 | 21.20 | 0.10 | -43.11 | -28.93 | 0.03 |
| 09/10/2026 01:05 AM | 20.63 | 5.90 | 21.20 | 0.10 | -42.52 | -28.23 | 0.03 |
| 09/10/2026 01:10 AM | 20.43 | 5.77 | 21.20 | 0.10 | -41.91 | -27.52 | 0.03 |
| 09/10/2026 01:15 AM | 20.29 | 5.69 | 21.20 | 0.10 | -41.29 | -26.80 | 0.03 |
| 09/10/2026 01:20 AM | 20.45 | 5.79 | 21.20 | 0.10 | -40.65 | -26.08 | 0.03 |
| 09/10/2026 01:25 AM | 20.33 | 5.71 | 21.20 | 0.10 | -40.00 | -25.35 | 0.03 |
| 09/10/2026 01:29 AM | 20.25 | 5.66 | 21.20 | 0.10 | -39.33 | -24.61 | 0.03 |
| 09/10/2026 01:34 AM | 20.39 | 5.75 | 21.50 | 0.10 | -38.65 | -23.86 | 0.03 |
| 09/10/2026 01:40 AM | 20.47 | 5.80 | 21.50 | 0.10 | -37.96 | -23.11 | 0.03 |
| 09/10/2026 01:45 AM | 20.67 | 5.92 | 21.50 | 0.10 | -37.26 | -22.35 | 0.03 |
| 09/10/2026 01:50 AM | 20.85 | 6.03 | 21.50 | 0.10 | -36.54 | -21.59 | 0.03 |
| 09/10/2026 01:54 AM | 20.87 | 6.04 | 21.50 | 0.10 | -35.82 | -20.82 | 0.03 |
| 09/10/2026 01:59 AM | 20.48 | 5.81 | 21.50 | 0.10 | -35.08 | -20.04 | 0.03 |
| 09/10/2026 02:05 AM | 20.39 | 5.75 | 21.50 | 0.10 | -34.33 | -19.26 | 0.03 |
| 09/10/2026 02:09 AM | 20.50 | 5.82 | 21.50 | 0.10 | -33.58 | -18.47 | 0.03 |
| 09/10/2026 02:15 AM | 20.67 | 5.92 | 21.20 | 0.10 | -32.82 | -17.68 | 0.03 |
| 09/10/2026 02:20 AM | 20.55 | 5.85 | 21.20 | 0.10 | -32.05 | -16.89 | 0.03 |
| 09/10/2026 02:24 AM | 20.63 | 5.90 | 21.20 | 0.10 | -31.26 | -16.09 | 0.03 |
| 09/10/2026 02:30 AM | 20.89 | 6.05 | 21.20 | 0.10 | -30.48 | -15.29 | 0.03 |
| 09/10/2026 02:35 AM | 20.83 | 6.02 | 21.20 | 0.10 | -29.68 | -14.48 | 0.03 |
| 09/10/2026 02:40 AM | 20.19 | 5.62 | 21.20 | 0.10 | -28.88 | -13.67 | 0.03 |
| 09/10/2026 02:45 AM | 19.98 | 5.48 | 21.20 | 0.10 | -28.07 | -12.86 | 0.03 |
| 09/10/2026 02:50 AM | 20.08 | 5.55 | 21.20 | 0.10 | -27.26 | -12.05 | 0.02 |
| 09/10/2026 02:55 AM | 20.00 | 5.49 | 21.20 | 0.10 | -26.44 | -11.23 | 0.02 |
| 09/10/2026 03:00 AM | 19.95 | 5.46 | 21.20 | 0.10 | -25.61 | -10.41 | 0.02 |
| 09/10/2026 03:04 AM | 20.74 | 5.96 | 21.20 | 0.10 | -24.78 | -9.59 | 0.02 |
| 09/10/2026 03:10 AM | 20.90 | 6.06 | 21.20 | 0.10 | -23.94 | -8.76 | 0.02 |
| 09/10/2026 03:15 AM | 21.03 | 6.13 | 21.50 | 0.10 | -23.11 | -7.94 | 0.02 |
| 09/10/2026 03:20 AM | 21.03 | 6.13 | 21.20 | 0.10 | -22.26 | -7.11 | 0.02 |
| 09/10/2026 03:24 AM | 21.03 | 6.13 | 21.20 | 0.10 | -21.42 | -6.28 | 0.02 |
| 09/10/2026 03:29 AM | 20.95 | 6.09 | 21.20 | 0.10 | -20.57 | -5.46 | 0.02 |
| 09/10/2026 03:35 AM | 21.00 | 6.12 | 20.90 | 0.10 | -19.71 | -4.62 | 0.02 |
| 09/10/2026 03:40 AM | 20.90 | 6.06 | 20.90 | 0.10 | -18.85 | -3.79 | 0.02 |
| 09/10/2026 03:45 AM | 20.38 | 5.74 | 20.60 | 0.10 | -18.00 | -2.96 | 0.02 |
| 09/10/2026 03:50 AM | 20.88 | 6.05 | 20.60 | 0.10 | -17.13 | -2.13 | 0.02 |
| 09/10/2026 03:55 AM | 20.93 | 6.08 | 20.60 | 0.10 | -16.27 | -1.30 | 0.02 |
| 09/10/2026 04:00 AM | 20.85 | 6.03 | 20.30 | 0.10 | -15.40 | -0.47 | 0.02 |
| 09/10/2026 04:05 AM | 20.56 | 5.86 | 20.30 | 0.10 | -14.53 | 0.37 | 0.02 |
| 09/10/2026 04:10 AM | 20.28 | 5.68 | 19.90 | 0.10 | -13.66 | 1.20 | 0.02 |
| 09/10/2026 04:15 AM | 19.98 | 5.48 | 19.90 | 0.10 | -12.79 | 2.03 | 0.02 |
| 09/10/2026 04:20 AM | 19.37 | 5.05 | 19.90 | 0.10 | -11.92 | 2.85 | 0.02 |
| 09/10/2026 04:25 AM | 19.08 | 4.83 | 19.90 | 0.10 | -11.05 | 3.68 | 0.02 |
| 09/10/2026 04:30 AM | 18.40 | 4.30 | 19.90 | 0.10 | -10.18 | 4.51 | 0.02 |
| 09/10/2026 04:34 AM | 17.59 | 3.62 | 19.90 | 0.10 | -9.31 | 5.33 | 0.02 |
| 09/10/2026 04:40 AM | 16.70 | 2.83 | 19.60 | 0.10 | -8.43 | 6.16 | 0.02 |
| 09/10/2026 04:45 AM | 15.67 | 1.88 | 19.60 | 0.10 | -7.56 | 6.98 | 0.02 |
| 09/10/2026 04:49 AM | 14.46 | 0.73 | 19.60 | 0.10 | -6.69 | 7.79 | 0.02 |
| DateTime | MPSAS | NELM | Temp | EncOffset | SolarAlt | LunarAlt | LunarPhase |