It’s officially galaxy season, and it’s named so for a very good reason. This is the time for longer focal lengths and small galaxies to shine, though there are still some great wider field opportunities to be had, like Markarian’s Chain and the Leo Trio.
Rather than repeating ourselves for each and every galaxy, there are some imaging and processing tips that apply to many of the objects on this list. Galaxies largely emit light in the visible spectrum, so you’ll want to be using RGB techniques to collect and process your data. Luminance is where you can really add detail, so if using a mono camera, it’s really worth collecting at least as much Lum data as your RGB. A number of these galaxies also have regions that emit in Hydrogen Alpha, so it’s often worth collecting Ha data too. This wants to be added in carefully, either by combining your Ha with your red channel, or by keeping it separate and using layering techniques to only bring it through in active regions.
So with those general galactic tips in mind, let’s get straight into our astrophotography targets. They’re arranged by constellation, and where better to start than with our favourite interstellar Lion.
M65/M66/NGC3628 – The Leo Trio
Mag: 9.3, 8.9, 9.5
Let’s jump straight in with not one, but three classic Spring galaxies that form the Leo Triplet. The trio is relatively bright and make a stunning visual impact largely for the differences between the three galaxies. If you’re looking for a real challenge, try to capture the tidal tail of NGC 3628 – you’ll want long exposures (think 30 mintues) and a very dark sky.
NGC 2903 is a relatively bright galaxy just south of the Lion’s head. You should be able to get the core and bar without too much difficulty, then work on capturing the faint sweeping outer arms.
M81 and M82 – Bode’s Galaxy and the Cigar Galaxy
Mag: 6.9, 8.4
One of the most famous galactic pairings, M81 and M82 are fantastic captured in a single image or mosaic, but both make excellent targets in their own rights.
Although M81 is a bright galaxy, it can take long exposures and dark skies to bring out detail in the spiral arms. Boost contrast to balance the yellow core with the bluer spiral arms. For M82, gathering additional Ha data can bring out the rich detail in the starburst core.
NGC 3184 is a large spiral galaxy with a relatively small nucleus. A large number of hot, young stars give the galaxy its blue colour, contrasting with redder regions of star formation. Spend as much time as possible on the Luminance to capture the maximum amount of detail in this tricky target.
We don’t have an NGC 3184 in our gallery – will you be the first?
Messier 97 – the Owl Nebula
The Owl Nebula is one of only two nebula on this list, and one of the few targets that you can choose to image exclusively through narrowband filters. An Ha/OIII composite can do a great job of capturing the outer shell. Try mapping the Ha to the red channel and the OIII to both blue and green. Its small size makes it well suited to longer focal lengths.
NGC 3718 and NGC 3729
Mag: 10.5, 11.6
This pair of galaxies makes a tricky target, but the unusual warped shape of NGC 3718 makes it a rewarding challenge. You should also be able to capture Hickson Group 56 nearby.
Messier 109 is a classic barred spiral galaxy with a clearly defined bar and spiral arms. A wider field reveals a large number of faint fuzzies in the vicinity, including what are thought to be three satellite galaxies of M109.
Messier 101 – the Pinwheel Galaxy
M101 is a big, faint, face-on spiral galaxy recognisable by its wonderfully asymmetric spiral arms – try using Ha data to emphasise the detail in them. If using a (very) wide field of view, look out for peculiar dwarf galaxy NGC 5475 nearby.
NGC 4631 and NGC 4656 – The Whale and the Hockey Stick
Mag: 9.3, 10.2
The Whale and Hockey Stick are an usual looking pair of galaxies commonly imaged together. The Whale is an edge-on spiral that actually has a partner galaxy much closer than the Hockey Stick in the form of NGC 4627, a small elliptical galaxy ‘riding’ the Whale’s back. In fact, this patch of sky is full of distant galaxies, making it a great target for faint fuzzy hunters.
NGC 4244 – The Silver Needle Galaxy
The Silver Needle in Canes Venatici is an edge-on galaxy, not to be confused with the more famous Needle Galaxy in Coma Berenices. It lacks the firmly defined dust lanes and central bulge of the Needle, but careful processing brings out a number of finer details and jewels within the galaxy. Try to bring out the yellow central core against the blue of the arms.
There’s no Silver Needle currently in our gallery – let us know if you capture it.
The subject of our winning 2015 Competition image, M106 is a stunning spiral galaxy complete with bright core, hot young blue star clusters and red stellar nurseries. As well as companion galaxy NGC 4248 and the larger NGC 4217 which can both be captured alongside M106, the whole area is full of faint fuzzies, making it a fascinating and rewarding area to image.
Messier 94 – The Croc’s Eye Galaxy
M94 is a face-on spiral galaxy that poses the challenge of a bright core and an incredibly faint outer shell. Try taking exposures as long as your system can manage to capture the shell and combine with shorter exposures to avoid blowing out the core.
Messier 63 – The Sunflower Galaxy
M63 is recognisable for the deep dust lanes towards the edge of the spiral arms. You’ll want a night of good seeing to capture as much detail as possible here, along with the galaxy’s faint outer halo. It’s worth adding some Ha data if possible to capture the Ha emission regions in the spiral arms.
Messier 51 – The Whirlpool Galaxy
A bright, beautiful deep sky object and great beginner target, the Whirlpool Galaxy reveals more of its intricate structures and surrounding halos the more data you gather. Even a modest night’s imaging will start to reveal the ‘bridge’ to NGC 5195 and deep dust lanes in the spiral arms. There have also been three supernovae in M51 in recent years, which makes it not only a picturesque galaxy, but one of scientific interest.
If you’re looking for a challenge, try small, faint spiral galaxy NGC 4559. It has a number of interesting details, including the dust lanes near the core and very faint outer arms. Although ideal for longer focal lengths, there are a huge number of faint fuzzies in the surrounding region.
NGC 4559 is another great Spring target that’s yet to find its way into our gallery, can you capture it?
NGC 4565 – The Needle Galaxy
The edge-on Needle Galaxy is a good target to really go for detail on. Dust lanes run along its entire length, and there are some interesting details near the bulging core. It also makes another good target for a deep field.
NGC 4725, NGC 4747 and NGC 4712
Mag: 9.2, 12.12, 12.8
NGC 4725 is unusual in that it only has one spiral arm. It’s relatively bright with a notable halo, and a number of potential companions nearby. NGC 4712 is close, but far further away so not interacting with NGC 4725, while NGC 4747 is being torn apart by it, with a pronounced tidal tail. If you have a really widefield, you may be able to capture planetary nebula LoTr5 along with all three galaxies.
Messier 64 – The Black Eye Galaxy
M64 has a dark band of dust close to the central core, giving rise to the galaxies name. There’s little definition in the arms and the galaxy appears more haloed than defined, but going deep on the central region can capture detail in the dust surrounding the core.
Messier 104 – The Sombrero Galaxy
M104 is another edge-on galaxy, though with a more notable tilt than others on this list. It has a very bright core and central bulge, and pronounced dust lanes running along its length. It’s not a particularly colourful galaxy, so if you find yourself pushed for time, consider aiming for a stunningly detailed mono image and leave the RGB for another day.
Mag: Varied – main galaxies 9.2-13
Markarian’s Chain is a string of galaxies across Virgo that make for a show-stopping image. The deeper you go and the more data you can gather, the more faint galaxies you’ll find, with a variety of fascinating details and cores.
Have a Spring Target or some imaging tips to add to the list? Let us know in the comments below.