What to observe in the sky in September 2025 with a smart telescope.
29 Aug. 2025
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September 2025 astronomical calendar
It is recommended to observe nebulae and galaxies when the Moon is not visible. Its brightness diminishes the darkness of the sky and reduces the quality of observations of faint and diffuse objects.
Refer to the following calendar for the best days this month.
September 7
Total eclipse of the Moon — visible from Europe, Africa, Asia, and Oceania
Read our full article to learn more.
September 12
Close approach of the Moon and the Pleiades
September 14
Last Quarter Moon
September 15
The Andromeda galaxy season has begun
September 21
New Moon — partial solar eclipse visible from New Zealand
September 22
September Equinox
September 30
First Quarter Moon
Celestial Scene of the Month
Northern sky
The constellation Cassiopeia boasts one of the richest star-forming regions along the plane of the Milky Way, displaying a vast complex of ionized hydrogen gas that encompasses several remarkable objects.
The Bubble Nebula (Caldwell 11) was sculpted by the powerful stellar wind of a hot, massive star, which has carved a nearly spherical cavity into the surrounding interstellar medium. Nearby, the Lobster Claw Nebula (Sh2-157) reveals intricate arcs and filaments of glowing gas, ionized by multiple energetic stars embedded within its structure.
This region is also home to several open star clusters, including Messier 52 and NGC 7510. The Lobster Claw Nebula lies between the Bubble Nebula and NGC 7510.
Southern sky
What about capturing nebulae from another galaxy and one of the largest globular star clusters in the same field of view?
Yes, it’s possible with your Vespera. 47 Tucanae (NGC 104) lies close to the Small Magellanic Cloud (SMC). While the SMC is such an extended target that it requires mosaic mode to capture in its entirety, you can still frame one of its most fascinating regions together with the globular cluster.
This particular region of the SMC contains a cloud of nebulae that resembles a cosmic fireworks display (NGC 249,NGC 261, NGC 267 ...). To make these nebulae stand out, the dual-band filter is essential. However, using it reduces the brightness of the globular cluster. For the best results on both objects, you’ll need to capture one image with the dual-band filter and another without it, then combine the two.
"Plan my Night" of the month
Suggested observation program you can automate with "Plan My Night."
Give each object as much observation time as you can to get the best results.
Northern sky
Do not use the dual band filter for this plan.
| Time | Target |
|---|---|
| Early Night |
Andromeda Galaxy - M31 |
| Mid Night |
Iris Nebula - Caldwell 4, NGC 7023 |
| Late Night |
Triangulum Galaxy - M33 |
Southern sky
Do not use the dual band filter for this plan.
| Time | Target |
|---|---|
| Early Night |
Omega Nebula a.k.a. Swan Nebula.a.k.a. Horseshoe Nebula. - M17 |
| Mid Night |
Caldwell 101 , NGC 6744 |
| Late Night |
Tarantula Nebula, HII region (emission nebula) in the Large Magellanic Cloud, magnitude 8 |
Around the full moon
During the few nights surrounding the full moon, it's best to focus on star clusters, which are less affected by the Moon’s light pollution.
Northern sky
The Double Cluster, Caldwell 15.Open clusters. Mag: 3.7. Constellation: Perseus
Southern sky
The Ptolemy's cluster, M7. Open cluster on the Milky Way backdrop. Mag. 3.3. Constellation: Scorpius.
Challenging Target of the Month
LDN 673: A dark nebula on golden backdrop
Visibility: Northern hemisphere
Constellation: Aquila (Eagle)
Type: Drak nebula
LDN 673 is a prominent dark nebula in Aquila, composed of dense clouds of dust and molecular gas that obscure the background stars of the Milky Way. Its network of filaments and dense cores marks regions where star formation is actively occurring, with embedded protostars revealed in infrared surveys. Observationally, it appears as irregular dark lanes against a rich star field that highlights the interplay between interstellar dust and the stellar background.
The fighting dragons of Ara a.k.a.Rim Nebula - NGC 6188
Visibility: Southern hemisphere
Constellation: Ara
NGC 6188 is a beautiful overlooked emission nebula, spanning several dozen light-years and illuminated by the intense radiation of nearby young, massive stars. Its glowing hydrogen gas forms intricate arcs, filaments, and cavities, shaped by stellar winds and radiation. NGC 6188 stands out against the surrounding star field and requires the dual band filter and many hours of acquisition to reveal its sticking structure.
Magnitude and angular size reminder
