Putman Mountain Observatory
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This image was taken from the observatory in January 2012 and shows Bode's Galaxy, also known as Messier 81 which was discovered by Johann Bode in 1774. In 1779, Charles Messier re-identified the galaxy and listed it in the Messier catalog as M81. This object is a very large spiral galaxy approximately 12 million light years from earth in the constellation Ursa Major (the Big Dipper). The core of M81 harbors a super massive black hole and older, yellow colored stars. In contrast, the spiral arms contain many, newly formed blue-hot suns that are forming in the hydrogen-alpha regions of the spiral arms. Below M81 is a faint companion galaxy called Holmberg IX.774
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Current Weather Information
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Live Weather data posted to Weather Underground. Click on the icon below to link to
historical weather data at Weather Underground.
Today's Highs and Lows:
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Selected Readings for Last 7 Days:
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Cloud Monitor
 This chart shows certain weather information monitored by the Boltwood Cloud Sensor. This device measures the amount of cloud cover by comparing the temperature of the sky to the ambient ground level temperature. The sky temperature is determined by measuring the amount of radiation in the 8 to 14 micron infrared band. A large difference indicates clear skies, whereas a small difference indicates dense, low-level clouds. This allows the sensor to continuously monitor the clarity of the skies, and to trigger appropriate alerts in the observatory. |
Current Sky
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Dark Sky Monitor
Current Mag/Sq Arcsec:
Updated every 15 minutes from dusk to dawn
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This chart shows the last current reading from the Sky Quality Meter (SQM). These readings are updated every 15 minutes. The SQM is an ethernet connected device made by Unihedron and is monitored by SQM Reader Pro Software by Knightware. The SQM measures sky brightness each night and provides a quantitative analysis of sky darkness from night to night. Fluctuations in relative darkness levels are caused by the phases and position of the moon in the sky and the milky way as it passes over the SQM's field of view. The SQM measures darkness in magnitudes per square arc second (Mag/Sq Arcsec) of sky. The chart also converts the Mag/Sq Arcsec reading into a theoretical Naked Eye Limiting Magnitude (NELM), which represents the faintest magnitude object that would be visible to the naked eye. This is a very dark site with naked eye limiting magnitudes ranging from 6.5 to 7.0 with no moon. |
Historical Mag/Sq ArcSec:
Updated every 15 minutes from dusk to dawn
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The rising and setting of the moon in the sky will affect the dark sky monitor readings. Moon rise and set times are indicated to explain fluctuations in relative sky darkness. |
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| This chart shows historical sky darkness readings over the last several hours. A new plot is marked every 15 minutes. No readings are taken after sunrise. |
Clear Sky Clock Forecast
Jetstream Forecast (30,000 ft / 300mb)
Wunderground Radar (San Antonio)
NOAA IR Radar
