M88 and M91 - Spiral Galaxies in Coma Berenices Astrophotography
Updated: Aug 24
Messier 88 and Messier 91 are two galaxies that are part of the Virgo Supercluster in the constellation Coma Berenices. Both galaxies can easily be photographed in the same field of view using a telescope with a focal length of about 400mm. In this post, you will find information, images, and tips to photograph M88 and M91.
Object Designation: M88, NGC 4501 & M91, NGC 4548
Constellation: Coma Berenices
Object Type: Spiral Galaxy (M88) & Barred Spiral Galaxy (M91)
Distance: 47 & 60 million light-years away
Magnitude: 9.5 & 11.0
Discovery: Charles Messier in 1781
M88 and M91 are not easy targets for beginners, they appear small and faint, but with bright cores. Imaging both individually with a long focal length telescope is ideal, but you can also do as we did and capture both in the same frame of your wide-field telescope.
M88 & M91 Astrophotography from Bortle 2 Skies
November 2023
It was important for us to photograph M88 and M91 and get great results so that we could add them to our growing Messier Catalog. Upon checking the framing for each on SkySafari, both seemed to fit just fine in our refractor telescope's field of view, mostly thanks to the full-frame camera.
Instead of centering each object and imaging them separately, I decided to capture both at once and do not regret it! The image turned out great, and many other galaxies can be seen in the field of view. It is also interesting to see how similar both objects are in size and brightness.
I spent a total of 20 hours on this picture, using RGB and HA filters, and am happy with the result. I especially like the bit of HA visible in M88, although that's all I could get out of the Hydrogen Alpha filter.
This was taken from our Bortle 2 observatory telescope at Utah Desert Remote Observatories!
Click the image to see it in full resolution!
GEAR USED:
Camera: QHY600M
Telescope: Stellarvue SVX130
Mount: 10Micron GM1000 HPS
Guiding: ZWO ASI 290MM Mini
Accessories: Moonlite Nitecrawler focuser / Pegasus Astro Ultimate Powerbox
Processing: Pixinsight, with R-C Astro plugins. Final touches in Skylum Luminar Neo
ACQUISITION DETAILS:
Total Exposure Time: 20 hours
Exposure Time per frame: 10 minutes
Filters: Chroma 3nm R/G/B/H
Gain: 56
How to Find M88 and M91
Messier 88 and Messier 91 can be difficult to find. Although part of the Virgo Supercluster of galaxies, both M88 and M91 are located in the constellation Coma Berenices (and not Virgo). To find them, look halfway between the Coma Berenices and Virgo constellations. The objects can be found not too far from the closest bright star from Leo.
Messier 88 can be spotted using any telescope or a large pair of astronomy binoculars, and looks like an elongated blurry patch of light. Messier 91 is fainter and one of the faintest objects in the Messier catalog. M91 can be seen with medium to large-size telescopes, but is not really visible with binoculars. For both M88 and M91, be sure you are actually looking at the right objects and not one of the many other galaxies making up the Virgo cluster.
Messier 88 and Messier 91 are close to many galaxies, including several Messier objects like:
M64 (The Black Eye Galaxy)
Galaxies from Markarian's Chain
M88 and M91 are best observed and photographed in the Spring season.
Messier 88 and Messier 91 Information
Let's learn more about the spiral galaxy M88 and the barred spiral galaxy M91.
Discovery
M88 and M91 were both discovered by Charles Messier on the same night of March 18th, 1781.
On this important night, Messier added a total of nine objects to his catalog (M84 to M92) with M91 being his last.
Charles Messier was one of the most important figures of astronomy. He dedicated his life to discovering comets and compiling a list of deep sky objects. He died on April 12, 1817 in Paris, and is buried at the Père Lachaise Cemetary. We have an ongoing project to decorate Messier's grave for several decades. You can learn more about the project and participate on our Charles Messier Grave Decoration page.
Here is what Charles Messier noted upon discovering M88:
"Nebula without star, in Virgo, between two small stars & one star of the sixth magnitude, which appear at the same time as the nebula in the field of the telescope. Its luminosity is one of the faintest, & resembles the one reported in Virgo".
And here are his notes for M91:
"Nebula without star, in Virgo, above the preceding No. 90: its light is still fainter than that of the above".
Messier 88
Messier 88 is a spiral galaxy located 47 million light-years away in the constellation Coma Berenices. It has a magnitude of 9.5 and looks visually similar to the Sunflower Galaxy (M63). M88 has 400 billion stars and has a diameter of 105,000 light-years.
M88 was one of the first galaxies to be identified as a spiral galaxy. It is on a highly elliptical orbit, at the moment between 0.3 and 0.48 million parsecs from the center of the Virgo Supercluster. M88 is expected to drift towards the Virgo Supercluster's center of gravity where the giant Messier 87 currently lies, and reach the core in 200 to 300 million years.
On May 28, 1999, a supernova occurred in the galaxy and was designated as SN 1999cl when discovered a day later. The supernova had a magnitude of 16.4, and became brighter until reaching mag 13.6 on June 5, 1999. The supernova is believed to have happened when a white dwarf exploded, and was categorized as a Type Ia supernova.
Messier 91
Messier 91 is a barred spiral galaxy located 60 million light-years away in the constellation Coma Berenices. It is getting further and further away from Earth at a speed of 486 km/s. It has a magnitude of 11.0 and is the faintest object in the Messier catalog. M91 is home to 400 billion stars and has a diameter of 100,000 light-years.
Messier 91's central bar is angled at 65/265 degrees and is very obvious in pictures.
Charles Messier made the mistake of cataloging M91 as M58 when he discovered the galaxy. For years, M91 was considered a "missing entry" until amateur astronomer William C. Williams matched M91 with NGC 4548... in 1969.
M88 and M91 by NASA
Both Messier 88 and Messier 91 were photographed by the Hubble Space Telescope.
The picture of M88, which you can see on the left side, shows a close-up view of the core of the galaxy, with thick spiral arms around it. Several dark bands and star clusters can be spotted in the arms swirling around the core. The image combines visible and infrared data from Hubble's Wide Field Camera 3 (WFC3).
The picture of M91, which you can see on the right side, shows a centered view on the galaxy's barred design and two main spiral arms around it. The image combines ultraviolet, visible, and infrared wavelengths. Just like M88, it was also taken with the HST's WFC3 instrument.
Which one of these two galaxy images is your favorite by the Hubble Space Telescope?
Cool Facts About M88 and M91
Both were discovered in 1781, in Charles Messier's last discovery night
M91 was a "lost entry" for many years
Part of the Virgo Supercluster of galaxies
See the different types of galaxies on our galaxy gallery page.
Single Shot and Processing of M88 and M91
Below you can see what a single shot of 10 minutes looks like on both galaxies. As you can see, M88 and M91 both fit nicely in our field of view, with a lot of room to spare thanks to the extended field of view from our full-frame camera.
Many other galaxies are visible all across the frame, especially near the edges which we sadly had to crop out due to tilt and vignetting issues.
Processing this data was quick and not too difficult. The part that is not easy is to process the galaxies evenly and not ruin how the much smaller objects look around the area.
Because of how faint M88 and M91 are, you'll also need to make sure that the core of each galaxy doesn't get blown out as you bring up the brightness and colors in the spiral arms.
Messier 88 and Messier 91 FAQ
In which constellation are the M88 and M91 galaxies located?
You can find both M88 and M91 in the constellation Coma Berenices.
How big are M88 and M91?
M88 and M91 are both large, with almost the same size. M88 has a diameter of 105,000 light-years while M91 has a diameter of 100,000 light-years.
How far are the M88 and M91 galaxies?
M88 is located approximately 47 million light-years away from Earth, while M91 is 60 million light-years away.
How long should my exposure time be when photographing M88 and M91?
We took 600-second exposures from our Bortle 2 site using our f/5 refractor telescope. We recommend doing between 300 and 600 seconds but no longer in order to avoid blowing out the core.
Should I use a filter to image M88 or M91?
You do not need filters to image either target. M88 does have a little bit of HA gas in it, but none can be seen in M91. It might not be worth spending time with an HA filter unless you have plenty of time.
Final Thoughts
Messier 88 and Messier 91 are faint but beautiful galaxies in Coma Berenices. It is nice to capture both at once, as they both have the same size, and brightness, but visually clash thanks to M88 being a spiral galaxy and M91 a barred spiral.
Processing isn't too difficult assuming your exposure time wasn't too long. Make sure to frame your target the way you prefer in order to include as many interesting galaxies as possible in your field of view!
Clear Skies,
Galactic Hunter
