Messier 61 - Galaxy With a Tidal Tail in Virgo Astrophotography
Updated: Oct 10
Messier 61 is a barred spiral galaxy located in the Virgo Cluster within the constellation Virgo. It has a bright core and detailed spiral arms, and is a nice but challenging target for astrophotographers. In this post, you will find information, images, and tips on how to photograph M61 successfully.
Object Designation: M61, NGC 4303
Constellation: Virgo
Object Type: Barred Spiral Galaxy
Distance: 52.5 million light-years away
Magnitude: 10.2
Discovery: Barnaba Oriani in 1779 (also observed by Charles Messier in the same year)
Messier 61 is often compared to our own Milky Way in terms of structure. It has well-defined spiral arms, but the galaxy is not easy to capture with a small telescope and so it is a rewarding target for intermediate astrophotographers. With the right equipment, integration time, and sky, you can reveal M61's spiral arms details, star forming regions, and even the long but faint tidal tail that expels from the object as you will see in our picture!
M61 Astrophotography from Bortle 2 Skies
May 2023
I wanted to image M61 mostly so that I could add it to our own growing Messier Catalog. I knew that this was a galaxy that was in a part of the sky that didn't have any nebulosity, but also knew there would be many other galaxies in the background due to it being in Virgo.
I placed M61 to the right side of the frame so that I could also include some other large galaxies nearby, such as NGC4378 which is visible on the upper left side in our wide field version.
I spent a total of 12 hours on this picture using a color camera, and realized that it was not enough time even from a Bortle 2 site. I did what I could to bring out the tidal tail visible on the left side of M61, and this brought out a lot of noise which would be much cleaner with more integration time. Luckily, I re-processed the image after cropping it and so the close-up version is much nicer!
This was taken from our Bortle 2 observatory telescope at Astronomy Acres!
Click the image to see it in full resolution!
GEAR USED:
Camera: ZWO ASI2600MC
Telescope: Celestron RASA 8
Mount: 10Micron GM2000 HPS
Accessories: Celestron Focuser / PrimaLuceLab Eagle 5S
Processing: Pixinsight, with R-C Astro plugins. Final touches in Skylum Luminar Neo
ACQUISITION DETAILS:
Total Exposure Time: 12 hours
Exposure Time per frame: 300 seconds
Filters: N/A
Gain: 100
How to Find M61
Messier 61 is located in the Virgo Cluster, and can be a bit challenging to spot. To find M61, you can start by locating the bright star Spica in Virgo and then look toward the region where Virgo meets the neighboring constellation of Coma Berenices. M61 lies among many other galaxies, so be sure to verify your target to ensure you're observing or photographing the correct object.
M61 can be spotted using medium-sized and large telescopes, where it will appear as a faint, blurry patch of light with a slightly brighter core. Observing or imaging M61 with a longer focal length will help reveal its spiral structure, which may not be immediately obvious at lower magnifications. Unlike some of the smaller and fainter galaxies in the Virgo Cluster, M61 is bright and can be captured with most setups, although it is much easier with a large telescope.
Messier 61 lies in a galaxy-rich area, surrounded by several other Messier galaxies, including M49 and all the galaxies forming the Markarian's Chain.
Messier 61 is best observed and photographed in the Spring season when the Virgo constellation is high in the night sky.
Messier 61 Information
Let's learn more about the barred spiral galaxy M61.
Discovery
Messier 61 was first discovered by the Italian astronomer Barnaba Oriani on May 5th, 1779. Barnaba Oriani was not just an astronomer, but also a scientist, a geodesist, and a priest.
Just 6 days later, Charles Messier also independently added the galaxy to his catalog on May 11, 1779. He actually spotted the object on the same night as Oriani, but wasn's sure if it was a comet.
Here is what Charles Messier noted upon finding M61:
"Nebula without star, similar to a faint comet. It resembles those reported in the Virgo constellation, situated close to the star of the sixth magnitude".
Galaxy Information
Messier 61 is one of the largest barred spiral galaxies in the Virgo Cluster, with a size of approximately 100,000 light-years, making it comparable in diameter to our Milky Way.
Its well-defined spiral arms are rich with star-forming regions, and M61 is considered as being a starburst galaxy.
At least 8 supernovae have been observed in Messier 61 since 1926.
The Tidal Tail in M61
One thing shocked me when processing this data: a very faint trail of dust visible by the galaxy's side. At first, I thought it was a hair that somehow got through the calibrated data, but I kept processing the file and quickly realized that it was definitely some dust in space!
I believe that this is a tidal tail, which is also seen in some other galaxies. You can see the inverted picture here, where the tail is clearly visible.
Tidal tails are long, thin streams of stars, gas, and dust that are ejected from galaxies as a result of gravitational interactions, usually during close encounters or mergers with other galaxies. Those tails form when the gravitational pull of one galaxy distorts the other, which stretches and pulls material out into space. They can extend for hundreds of thousands of light-years and are visible as faint curving structures extending from the main body of a galaxy.
M61 by NASA
Messier 61 was photographed by both the Hubble Space Telescope and the Very Large Telescope (VLT) in Chile.
Hubble’s picture came out in 2004, and showed some great details of M61’s spiral arms, including the star-forming regions and dark dust lanes. You can see it here on the left. As you notice, the mosaic was not finished, but that's simply because it was not needed for the scientific aspect of the observation.
The second picture shows the result from the VLT (Very Large Telescope) in Chile, which is a ground telescope. This one came out in May 2020, as the galaxy was observed to study the 2020 supernova (SN 2020jfo) among others.
Cool Facts About M61
First observed by Charles Messier on the same night as Barnaba Oriani, but added to Messier's catalog only 6 days later
M61 has hosted at least 8 supernovae
Similar in size to the Milky Way
See the different types of galaxies on our galaxy gallery page.
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Single Shot and Processing of M61
Below you can see what a single shot of 5 minutes looks like for M61 using the RASA 8, which is f/2! As you can see, There isn't much to see, and the only obvious galaxy is M61!
Many other galaxies are visible all across the field, but difficult to see on a single shot.
Processing this data was very difficult, mostly because I was focused on revealing the tidal tail. I first processed the image without doing any crop, and ended up with a noisy mess which is till exported as I wasn't sure if I could do better. I processed this on video as a case study in our Galaxy Processing Guide, so feel free to take a look!
3 weeks later, I decided to re-process the data but this time by first doing a heavy crop and only caring about the galaxy and its tail. This ended up being much smarter for my goal and the result was much cleaner!
Messier 61 FAQ
In which constellation is the M61 galaxy located?
You can find M61 in the constellation Virgo.
How big is M61?
M61 has a diameter of 100,000 light-years, which is similar to our Milky Way.
How far is the M61 galaxy?
M61 is located approximately 52.5 million light-years away from Earth.
How long should my exposure time be when photographing M61?
We took 300-second exposures from our Bortle 2 site using our f/2 RASA telescope. We usually do 600sec for most objects, but cut that number in half for galaxies when using a fast telescope like the RASA. This is to make sure we don't end up with galaxies that have a core that is way too bright! 300 seconds ended up being a good choice.
Should I use a filter to image M61?
You do not need filters to image this target, although you can try to also use an HA filter and see if you have star forming regions visible when you combine everything. We did not use any filter.
Final Thoughts
Messier 61 is not a very easy target to photograph or process, but it is the perfect target for astrophotographers looking for a challenge! The tidal tail is truly what makes this target difficult, as you'll need a long integration time, dark skies, and patience while processing the data!
Clear Skies,
Galactic Hunter
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