Hot July Sun

Good Seeing!

Virginia weather in mid-July is hot and humid. I had done no solar observing for a month while steamy, tropical, rainy conditions persisted day after day. Finally, on the morning of July 16th, cloudless skies were temporarily present. Sometimes, at this time of year, clear skies will last for a few precious early morning hours before the usual afternoon clouds return. Sometimes these rare morning opportunities also include very steady air. On July 16th the air was very still, but also very humid! Moisture condensed on my telescope and mount until they reached ambient temperature. The steady air allowed excellent image detail, the best this year so far. Two modest sunspots were visible along with numerous filaments and some nice prominences.

This 21-image mosaic, made with a 2X Barlow lens, shows the solar disc on July 16th. In the upper left is sunspot 1793. Slightly below center is sunspot 1791.

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Next is the inverted version of the previous image. It highlights filaments suspended above the solar disc. Filaments are dark in the previous image, but look like white clouds in the inverted image.

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Here is a nicely detailed image of sunspot 1793 alone. The steady air allowed radial lines to be seen in the penumbra surrounding the darkest part of the sunspot.

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Sunspot 1791, a bit smaller than 1793, was accompanied by several dark filaments.

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An inverted version of the filaments, with sunspot 1791 in the upper right, shows the filaments as white floating clouds.

Three nice prominences were displayed along the Sun's southeastern rim, portrayed here in yellow in the following 3-image mosaic.

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It's hard to get a detailed image showing both prominences and surface features in one exposure. Prominences are relatively faint, so they require longer, more sensitive exposures. Disc features are relatively bright, so they are overexposed when acquiring prominence detail. I made the following picture by combining two images, one designed to capture faint prominence details, and the other designed to capture disc details.

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Clouds began moving in front of the Sun after a little more than an hour of frantic imaging. How many days will pass before I can observe again?.