Astronomical Diary
Calendar of Astronomical Events SEPTEMBER 2022
Date Event Time
1 Aurigids (ZHR = 6) 04:00 AM
8 Moon at Perigee (Distance = 364,562.790) 02:19 AM
8 Close Approach of Moon and Saturn 08:35 PM
9 ε-Perseid (ZHR = 5) 02:00 AM
11 Close Approach of Moon and Jupiter 11:16 PM
19 Moon at Apogee (Distance = 404,487.505) 10:43 PM
23 September Equinox 09:04 AM
27 Jupiter in Opposition 03:25 AM
Moon Phases
First Quarter
Sep 04 02:08 AM
Full Moon
Sep 10 05:59 PM
Last Quarter
Sep 18 05:52 AM
New Moon
Sep 26 05:55 AM
Rise and Set Times of Planets
Date Mercury Venus Mars Jupiter Saturn
Rise Set Rise Set Rise Set Rise Set Rise Set
Sept 01 07:33 AM 07:27 PM 04:48 AM 05:23 PM 11:10 PM 11:59 AM 07:38 PM *07:47 AM 05:02 PM *04:36 AM
Sept 11 07:08 AM 06:55 PM 05:01 AM 05:27 PM 10:51 PM 11:43 AM 06:55 PM *07:03 AM 04:21 PM *03:53 AM
Sept 21 06:04 AM 05:56 PM 05:13 AM 05:29 PM 10:30 PM 11:24 AM 06:11 PM *06:19 AM 03:39 PM *03:12 AM
Sept 30 04:57 AM 05:03 PM 05:23 AM 05:30 PM 10:08 PM 11:04 AM 05:32 PM *05:38 AM 03:03 PM *02:35 AM

* = following day

Stars and Constellation

The constellations best observed in September are Aries, Pisces, Cassiopeia, Cepheus, Lacerta, Pegasus, Ursa Minor, Draco, Cygnus, Lyra, Vulpecula, Sagitta, Hercules, and Corona Borealis in the northern constellations, while Capricornus, Aquarius, Sagittarius, Scorpius, Microscopium, Sculptor, Indus, Telescopium, and Corona Australis are located in the southern sky [1]. Figure 1 shows the view of the sky on 15 September at around 09:00 PM when the September constellations are situated overhead.

Fig1
Figure 1: The view of the night sky featuring the prominent September constellations showing the Northern and the Southern Hemisphere on 15 September at 09:00 PM using the Stellarium software

The constellation Cygnus, the Swan can easily be recognized as a large cross-shaped asterism known as the Northern Cross that is shaped by the stars Deneb (Alpha Cygni), Sadr (Gamma Cygni), Albireo (Beta Cygni), Fawaris (Delta Cygni) and Aljanah (Epsilon Cygni). The constellation Cygnus holds some interesting deep sky objects such as the North America Nebula (NC 7000), the Crescent Nebula (NGC 6888), the Blinking Planetary Nebula (NGC 6826), and the Fireworks Galaxy (NGC 6946) which are best-known telescope targets (Figure 2) [2].

Fig2a

Fig2b
Figure 2: The position of some prominent deep sky objects in the constellation Cygnus on 15 September at 9:00 PM using the Stellarium software

This month, the asterism known as the Summer Triangle can be observed in the night sky. It is formed by the stars Vega in the constellation Lyra with magnitude 0.0, Altair in the constellation Aquila with magnitude 0.75, and Deneb in the constellation Cygnus with magnitude 1.25. These stars are also the 5th, 12th, and 19th brightest stars in the night sky, respectively.

The constellation Vulpecula the Little Fox is a dim, unnoticeable object within the Summer Triangle (Figure 3). Located in this constellation is the first discovered planetary nebula, the Dumbbell Nebula (M27), which can be seen using a powerful binocular in a clear sky condition, and only under a telescope does the nebula’s double-lobed shape becomes visible.

Fig3a
(a)

Fig3b
(b)
Figure 3: The view of the northwestern sky showing the (a) asterism “Summer Triangle”, and within the asterism is the (b) constellation Vulpecula and the famous Dumbbell Nebula on 15 September at 07:30 PM using the Stellarium software

The winged horse from Greek mythology Pegasus is the inspiration for this conspicuous constellation in the northern sky. The constellation Pegasus is visible in the Northern Hemisphere from the end of the summer to the beginning of autumn. The constellation is well-known for housing the first exoplanet ever discovered, 51 Pegasi b around a sun-like star, as well as the M15 galaxy. The Great Square of Pegasus, an asterism that stands out in this constellation, is made up of four stars named Markab, Scheat, Algenib, and Alpheratz (Figure 4) [3].

Fig4
Figure 4: The view of the northeastern sky showing the position of the constellation Pegasus with its famous asterism “Great Square of Pegasus”, and its famous Pegasus Cluster M15, and the location of the Andromeda Galaxy on 15 September at 9:00 PM using the Stellarium software

Planetary Location

Mercury is visibly low in the western horizon shortly after sunset during the first week of the month. It will eventually be challenging to observe due to its proximity to the Sun. Venus remains a morning planet and is visible a few minutes before sunrise on the eastern horizon during the first week of the month. It will gradually be tricky to observe due to its low position on the eastern horizon.

Mars is first spotted during the late evening hour as it rises on the northeastern horizon. It will then reach its highest point in the sky a few minutes before sunrise. On the midnight of 17 September within the constellation Taurus, the Bull, the Moon and Mars will be seen paired closely as they rise in the eastern night sky, and will reach their highest point in the sky a few minutes before sunrise (Figure 5).

Fig5
Figure 5: The view of the northeastern sky showing the Moon and Mars within the constellation Taurus on 17 September at 12:00 AM using the Stellarium software

Jupiter and Saturn are visible for much of the night throughout this month. The Waxing Gibbous Moon and Saturn will pass in close proximity on 08 September at 08:35 PM, at about 3°43’ (Figure 6). Meanwhile, on 11 September at 11:16 PM, the Waning Gibbous Moon and Jupiter will have a close approach, with the Moon passing 1°48’ to the south of Jupiter (Figure 7). On 27 September at 03:25 AM located in the constellation Pisces the Fish, Jupiter will be in opposition, lying opposite to the Sun in the sky [4, 5]

Fig6
Figure 6: The view of the southeastern sky showing the Moon and Saturn on 08 September at 08:35 PM using the Stellarium software

Fig7
Figure 7: The view of the southeastern sky showing the Moon and Jupiter on 11 September at 11:16 PM using the Stellarium software

Meteor Shower

The Aurigid Meteor Shower, produced by Comet C/1911 N1 (Kiess), is a meteor shower active from 28 August to 05 September, with peak activity occurring on 01 September. During its peak, the Aurigids is estimated to produce 6 meteors per hour. The Aurigids’ radiant point is located in the constellation Auriga the Charioteer, which rises past midnight on the northeastern horizon and will remain visible until before sunrise (Figure 8) [6].

Fig8
Figure 8: The view of the northeastern sky during the peak of Aurigids on 01 September 2022 at 04:00 AM when the shower’s radiant is represented by the green solid circle.

The September ϵ-Perseids is a meteor shower active from 05 September to 21 September, with peak activity on 09 September. The September ϵ-Perseids is expected to produce 5 meteors per hour during its peak. The radiant of the shower, the constellation Perseus, rises in the eastern sky at around 09:00 PM. Figure 9 shows the position of the radiant in the eastern sky at 02:00 AM on 09 September [7].

Fig9
Figure 9: The view of the northeastern sky during the peak of ϵ-Perseids on 09 September 2022 at 02:00 AM when the shower’s radiant is represented by the green solid circle.

Meteor showers are observable through the naked eye, and no special equipment such as telescopes or binoculars is needed. Maximize the viewing experience by choosing a dark observation site away from the city lights under clear and moonless sky conditions.

September Equinox

September Equinox, also known as the Autumnal Equinox is on 23 September at 09:04 AM [8]. The September Equinox marks the first day of autumn in the Northern Hemisphere and spring for the southern hemisphere. During equinoxes, the Sun is directly pointing over the Earth’s equator, thus, creating nearly equal day and night. And also, on this day, the Sun exactly rises due east and exactly sets due west [9].

Watch: Astronomical Events for September 2022

Notes and References

*All times displayed are in Philippine Standard Time (PhST)

References:
[1] PAGASA Special Publication No. 840: The Philippine Star Atlas, 2019
[2] C. Guide, “Constellations: A Guide to the Night Sky” https://www.constellation-guide.com/constellations-by-month/september-constellations, Last accessed on 2022-08-16, 2022.
[3] K.A. Zimmermann, “Space.com Pegasus Constellation: Facts Notable Features” https://www.space.com/16743-constellation-pegasus.html, Last accessed on 2022-08-16, 2022.
[4] D. Ford, “In-The-Sky.org Guide to the night sky: Jupiter at opposition” https://in-the-sky.org/news.php?id=20220926_12_100, Last accessed on 2022-08-16, 2022.
[5] D. Ford, “In-The-Sky.org Guide to the night sky: Saturn at opposition” https://in-the-sky.org/news.php?id=20240908_12_100, Last accessed on 2022-08-16, 2022.
[6] D. Ford, “In-The-Sky.org Guide to the night sky: Aurigid meteor shower 2022” https://in-the-sky.org/news.php?id=20220901_10_100, Last accessed on 2022-08-16, 2022.
[7] D. Ford, “In-The-Sky.org Guide to the night sky: September -Perseid meteor shower 2022” https://in-the-sky.org/news.php?id=20220909_10_100, Last accessed on 2022-08-16, 2022.
[8] Philippine Astronomical Handbook 2022
[9] D. Ford, “In-The-Sky.org Guide to the night sky: September equinox” https://in-the-sky.org/news.php?id=20220923_07_100,Last accessed on 2022-08-16, 2022.


For more information, call or email:

Ms. Ma. Rosario C. Ramos, RCE
Chief, SSAS - RDTD
PAGASA - DOST
Diliman, Quezon City
Trunkline: 8284-0800 loc 106, 107, 116
Email add: astronomy@pagasa.dost.gov.ph