September signals longer nights with autumnal equinox, offers favorite sky treats

The month of September ushers in the much-awaited change of season—from the searing summer days to a tad drop of temperature that will lead up to the mildly cold autumn season.

An important event to “officially” signal this change happens on September 23, when the sun is again at its zenith—or straight overhead—as seen from Earth’s equator. This is called an equinox.

During an equinox, there will be an equal amount of day and night—that’s 12 hours each—and afterward, the lengths of days and nights in the Hemispheres will begin to shift.

In the Northern Hemisphere, for example, (this is where we in the UAE are situated) night times are bound to get longer, but the nights of those in the Southern Hemisphere will grow shorter.

In fact, experts estimate that sunrises here in the UAE for September are expected to occur between 6:03 and 6:13 in the morning. Sunsets, which often happen as late as 7:15 in the evening in the previous months, can now be expected to occur as early as 6:11 until 6:41 P.M.

Diagram showing Earth’s orientation during the September Equinox (Image Credit: eclipsegeeks.com)

Upcoming early night falls only mean one thing: more time for observations on planets and other night sky favorites!

To begin with, planets Jupiter and Saturn will be visible right after sunset until around past midnight.

On September 6, the largest planet of the Solar System will be spotted near the bright waxing gibbous moon just right after sunset. The Moon will be at 4.26° west-northwest of Jupiter, which will appear as a bright white “star” in the sky.

Moon-Jupiter Conjunction on September 6, 2019, at around 7 P.M. Image courtesy of Stellarium.

Two days later, on September 8, it will be the Saturn’s turn to skirt close to the Moon at 1.19°. The conjunction will be seen at the southern portion of the night sky right after sunset, with the Ringed Planet looking like a yellow-orange “star” just by the right of the Moon.

Moon-Saturn Conjunction on September 8, 2019, at 7:15 P.M. Image courtesy of Stellarium.

Meanwhile, with a powerful telescope, Uranus and Neptune could be seen as early as 10 P.M. until sunrise.

Keep your eyes peeled for Neptune on September 10, as it will be at opposition. This means that the blue gas giant will be situated directly opposite the Sun in the sky, which will allow the planet to be at its brightest.

Apparent view of Neptune as seen through a 14-inch telescope. Image courtesy of Stellarium.

The rest of the planets—Mercury, Venus, and Mars—will not be visible this month because they are positioned near the Sun in the sky.

The Moon in September

On September 14, the Earth’s lone satellite will be in its full phase. This is the best time to observe all the surface features of this celestial object, including the craters and maria, or the dark patches on the Moon’s surface.

The Moon will show itself as early as 6:35 P.M. as it rises from the east and will be up the entire night.

Full Moon taken last August 16, 2019 at the Al SadeemAstronomy Observatory. (Image Credit: AldrinGabuya/Al Sadeem Astronomy)

Meanwhile, deep-sky objects will best be seen on September 28, when the Moon is finally in its New phase.

The prominent ones include the Ring Nebula, Dumbbell Nebula, and the Milky Way Galaxy, which can all be seen in the early evening hours.

Some known autumn and winter deep-sky objects such as the Andromeda Galaxy, Pleiades, and even the Orion Nebula, will also grace the night sky in the early morning hours until sunrise.

It is predicted that this lunar phase will occur on this day. However, the month transition from Muharram 1441 to Safar 1441 shall take place two days later (September 30) in accordance with the Hijri Calendar 1441. ###

Summer Deep-sky objects: Top: Ring Nebula (Messier 57), Dumbbell Nebula (Messier 27); Bottom: Milky Way Galaxy central region (Image Courtesy of Aldrin Gabuya, Thabet Al Qaissieh/Al Sadeem Astronomy)
Autumn and Winter Deep sky objects: From left to right: Pleiades (M45), Andromeda Galaxy (M31), Orion Nebula (M42) (Image Courtesy of Thabet Al Qaissieh/Al Sadeem Astronomy)
REFERENCES

Astronomy Calendar of Celestial Events 2019. (n.d.). Retrieved from Sea and Sky: www.seasky.org/astronomy/astronomy-calendar-2019.html

Calendar of Astronomical Events. (n.d.). Retrieved from In-The-Sky.org: http://in-the-sky.org/newscal.php?year=2019&month=9&maxdiff=4#datesel

Islamic calendar 2019. (n.d.). Retrieved from Calendar.sk: https://calendar.zoznam.sk/islamic_calendar-en.php?ly=2019

Sunrise and sunset times in Abu Dhabi, September 2019.(n.d.). Retrieved from timeanddate.com: https://www.timeanddate.com/sun/united-arab-emirates/abu-dhabi?month=9&year=2019

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