September 2018 Sky Calendar
Aug 31, 2018 23:44:51 GMT
Post by Joe on Aug 31, 2018 23:44:51 GMT
CVAS Monthly Sky Calendar for September 2018
Venus – As Venus approaches inferior conjunction with the Sun next month it is sinking lower in the evening skies. It can be found in the southwestern horizon right after sunset. To start the month it is up only for 1 ½ hours with it being 14° high at sunset, by month end this decreases to only being up for less than 1 hour and only 6° high at sunset. Its phase for the month will go from 40% to 18%, its size going from 29.2 to 45.6 arc-seconds, with a very bright magnitude from -4.6 to -4.8 for the month.
Jupiter – Jupiter can be found in the southern western evening skies right after sunset. It is up for only 3 to 2 hours this month after sunset, so It is best to view it right after it gets dark enough to see it when it is highest up during the night. During the month the size goes from 34.7 to 32.6 arc-seconds with a magnitude going from -2.0 to -1.8.
Mars – This probably last good month where it might be easier to see some details on Mars for the next two years. It gets smaller as the month goes on so it best to try to view near the beginning of the month. It is best to try to view in when it highest up in the southern skies which for this month is an hour or two after sunset. It is now up for about 7 hours after sunset for the month. It is size during the month goes from 20.8 and 15.9 arc-seconds with it dimming a bit with its magnitude decreasing during the month going from -2.1 to -1.3.
Neptune – This is the best month of year to see Neptune as it is in opposition on the 7th of this month. Since it is at opposition, it is up for basically all night with it being up for at least 10 ½ hours the whole month. It is best wait until twilight is complete over to view to give it some time to rise up some at which point it will be visible in the SE skies right after twilight. To see it when it is at its highest in the sky in the south, at start the month this will be around 2AM, by month end will it be around 12AM. During the month its size will be around 2.3 arc-seconds with a magnitude of around 7.8. This is good time to try to see it largest moon Triton. At opposition, Triton will be at magnitude 13.4 and circles Neptune from a distance of 12 to 17 arc-seconds.
Uranus – As Uranus approaches opposition next month it up for a good part of the night, now rising around 10PM to start the month, by month’s end it rises at around 8PM. It is best viewed nearer to morning when it is highest up in the southern skies. To start the month it is due south around 4:30, by months end it is due south around 3AM. During the month, its magnitude will around 5.7 with a diameter of 3.7 arc-seconds.
A finder chart for Neptune and Uranus can be found at www.skyandtelescope.com/wp-content/uploads/WEB_UrNep18.pdf
Mercury – For the first part of the month Mercury can be viewed low on the eastern horizon shortly before sunrise but as it approaches superior conjunction with the Sun on the 21st it will drop lower and then is too close to the Sun to see for the rest of the month. To start the month it is up for 1 ½ hours, being 15° high by sunrise, which is not bad for Mercury. From the start of the month to the 15th to the end of the month, its phase will go from 65% up to 98%, it size from 6.3 arc-seconds to 5.0 arc-seconds and it magnitude from -0.80 to -1.5.
Fall Equinox – The Fall Equinox, the office start of fall, arrives at 9:54PM on the 22th.