Event Date: August 20th
Time: 5:30 AM
Brief
There are two things to look at this morning, in the eastern sky before Sunup: Mercury, at about its best apparition of the year for the morning sky, has now passed by Asellus Australis, east of it. The two are still visible in a telescope together, although a wider field is required to see them together. As the mornings pass, Mercury separates itself further from the star, reaching superior conjunction [with the Sun] in September.
Also, last week I mentioned the "other" triangle rising in the east at this time of year, with Jupiter, Venus and Sirius marking its points. As Venus separates further from Jupiter, the triangle is taking shape nicely. Venus is 29º from Jupiter and about 37º from Sirius. Can you predict which day that it will become isosceles, with Venus as the apex? I will reveal the answer in early September shortly before it happens.
Both of the mentioned viewings are shown zoomed out in the following images, while the second image shows where the Vega/Deneb/Altair triangle is at the same time, about an hour before Sunrise.
Time: 5:30 AM
Brief
There are two things to look at this morning, in the eastern sky before Sunup: Mercury, at about its best apparition of the year for the morning sky, has now passed by Asellus Australis, east of it. The two are still visible in a telescope together, although a wider field is required to see them together. As the mornings pass, Mercury separates itself further from the star, reaching superior conjunction [with the Sun] in September.
Also, last week I mentioned the "other" triangle rising in the east at this time of year, with Jupiter, Venus and Sirius marking its points. As Venus separates further from Jupiter, the triangle is taking shape nicely. Venus is 29º from Jupiter and about 37º from Sirius. Can you predict which day that it will become isosceles, with Venus as the apex? I will reveal the answer in early September shortly before it happens.
Both of the mentioned viewings are shown zoomed out in the following images, while the second image shows where the Vega/Deneb/Altair triangle is at the same time, about an hour before Sunrise.
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| click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp. |
Detailed
Notice with image two, that Altair is 6 minutes from setting, very low to the horizon. Although not visible except from the highest of elevations, with optical aid needed to try to see it through thick atmospheric pollution, we can still see Altair through most of the night; that gives us about 9 hours to do so and therefore, the entire triangle high in the sky shortly after Sunset. It is at this time of year that these three stars are seen at or near their highest during mid-evening hours, and the asterism dominates that section of the sky. Tomorrow, I will do a transit update of the triangle, while remember, that the Venus/Jupiter/Sirius trio continues to take shape for the next 2-4 weeks, depending on exactly what separation patterns you are looking for.
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