What to observe in the sky in May 2025 with a smart telescope

What to observe in the sky in May 2025 with a smart telescope

30 Apr. 2025

Best period for deep sky observation in May 2025

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. Near the time of the full moon, it’s best to focus on observing star clusters, as they are less affected by the sky’s brightness.

Refer to the following calendar for the best days this month.


Celestial Scene of the Month

Selection of a target or group of targets particularly suitable for mosaic capture.

Northern & southern hemisphere 

May marks the beginning of Milky Way season in the Northern Hemisphere. In the Southern Hemisphere, the Galactic Center also becomes more favorably placed for observation, especially once the full moon of May 12 has passed.

 

The first constellation from the heart of the Milky Way to make its appearance is Scorpius. Rich in deep-sky objects, it alone could offer enough targets to fill the next two months of observations. This month, let’s focus on the head of the Scorpion, the region surrounding the brilliant star Antares.

 

Antares is enveloped in a nebula with an unusual hue—a yellow tint, rarely seen in other nebulae. This color comes from the star itself: a red supergiant whose light illuminates the surrounding clouds of gas. Nearby, the stunning globular cluster Messier 4 adds depth to this celestial scene.

 

From the Northern Hemisphere, this target lies low on the southern horizon, making it slightly more challenging to observe. But the effort to find a dark site with a clear view to the south is well worth it.

 

Since these are reflection nebulae, it is recommended to not use the dual band filter.

 

"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 Hemisphere

Using the dual-band filter is not recommended for this plan.

Time Target
Early Night

Sombrero Galaxy - M104
Constellation: Virgo
Magnitude: 8, angular size: 8' x 5'

Mid Night


Ring nebula - M57, Planetary Nebula
Constellation: Lyra
Magnitude: 8.7, angular size: 1.3'

Late Night

Iris Nebula - Caldwell 4, 
Constellation : Cepheus
Magnitude: 7.2, angular size: 10'

Southern Hemisphere

Using the dual-band filter is recommended for this plan

 

Time Target
Early Night

NGC3114: open cluster associated with HII region
Constellation  : Carina
Magnitude: 4.2, angular size: 12'

Mid Night

Omega Nebula ( a.k.a. Swan / Horseshoe Nebula), emission nebula
Constellation : Sagittarius
Magnitude: 6, angular size: 12,5'

Late Night

Eagle Nebula - M16, emission nebula
Constellation :  Sagittarius
Magnitude: 6, angular size: 5'

Challenging Target of the Month

 

Rho Ophiuchi cloud complex
Visibility:
northern & southern hemisphere
Constellation: Ophiuchus / Scorpius

Let’s dive deeper into the region surrounding the star Antares and turn our attention to the nebulae that envelop the Rho Ophiuchi multiple star system (in the constellation Ophiuchus). Several young stars illuminate the nearby clouds of gas and dust, giving them a striking blue hue. Not far from there, dark nebulae overlap the stellar backdrop like delicate shadow puppets, their shapes cutting through the glow of the reflection nebulae.

 

To truly bring out the richness of this area, you’ll need a sky that is exceptionally dark.

 

For an even more rewarding challenge, try capturing a series of mosaic images covering the expanse from Antares to Rho Ophiuchi. Once assembled, these frames reveal a stunning panoramic view of the Rho Ophiuchi cloud complex—one of the most spectacular regions of the Milky Way thanks to its vivid palette of nebular colors.

 

Check out our dedicated article on capturing mega-mosaics for a step-by-step guide on how to plan and execute this kind of celestial project.

 

This region features a mix of different types of nebulae, so it’s best to observe it without any filter.

Astronomical events of the month

 

May 3–6

 

The planet Mars will pass through the Beehive Cluster, M44 (also known as Praesepe). On May 3, the Moon will also be nearby, adding to the spectacle.


This is a great opportunity to capture a unique view of this star cluster.


To photograph Mars alongside the cluster, start an observation by selecting M44 as your target. This way, you’ll benefit from stacking to better reveal the cluster’s details. Mars will inevitably be overexposed, but due to the significant difference in brightness between the two objects, it’s impossible to achieve a perfect exposure for both at once. Nevertheless, the result can still be visually striking.

The planet Venus in the Beehive Cluster

Magnitude and apparent size reminder