Event Date: September 17th
Time: 6:00 AM
Brief
As we approach the September equinox, we see Venus rising about 3 1/2 hours before the Sun, as seen from our latitude, followed by Regulus. The star is not only west of the Sun now; it is becoming further north each day. Since the Sun is rising about 1 1/2 minutes later each day while Regulus is rising a little less than 4 minutes earlier, it means that we will see Regulus for more than 5 minutes more each day before Sunrise during much of the autumn season.
Here is Regulus about an hour before Sunrise, already 13º above the horizon. Notice how it is very close to the ecliptic, less than 1/2º apart.
Time: 6:00 AM
Brief
As we approach the September equinox, we see Venus rising about 3 1/2 hours before the Sun, as seen from our latitude, followed by Regulus. The star is not only west of the Sun now; it is becoming further north each day. Since the Sun is rising about 1 1/2 minutes later each day while Regulus is rising a little less than 4 minutes earlier, it means that we will see Regulus for more than 5 minutes more each day before Sunrise during much of the autumn season.
Here is Regulus about an hour before Sunrise, already 13º above the horizon. Notice how it is very close to the ecliptic, less than 1/2º apart.
Detailed
By showing the celestial equator in the image as well as the ecliptic, the two merging below the horizon at this hour indicates how quickly the Sun is moving towards the equator and south of it at this time of year. Look also at Venus, which is a hair over 18º separated from Regulus. Since Venus is gradually speeding up in pro-grade motion, as I have mentioned several times over the last month or so, it will catch up with Regulus. While sometimes we view Venus with a large value of ecliptic latitude, this will be a time when we view it with a small one--almost that of Regulus' at the time that it catches up with the star. We will see a fine pairing of the two early next month. By remembering that Venus is moving further east each day, we can try to predict exactly which morning it will happen. Using its celestial plot in the image below zoomed in a bit, can you? Once again, as the celestial path of Venus shows, it is a very slow increase, yet still enough of one. Between now and tomorrow at this time for example, the planet moves about 4.5m in right ascension, and 14.6' in declination.
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| click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp. |
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