Claudine Bustamante

Claudine Bustamante

Modified & Updated: 08 Sep 2023


Located in the constellation Andromeda, Messier 110 (M110) is a fascinating galaxy that is often overshadowed by its more famous neighbor, the Andromeda Galaxy (M31). Despite being lesser-known, M110 holds many astonishing facts that will captivate both astronomy enthusiasts and casual stargazers alike. From its discovery by Charles Messier in the 18th century to its status as a dwarf elliptical galaxy, M110 offers a wealth of intriguing details to explore. In this article, we will delve into 17 astonishing facts about Messier 110, shedding light on its unique features, scientific significance, and contribution to our understanding of the vast and mysterious universe we inhabit.

Table of Contents

The Companion of Andromeda Galaxy

Messier 110 (M110), also known as NGC 205, is a dwarf elliptical galaxy located in the constellation Andromeda. It is a satellite galaxy of the famous Andromeda Galaxy (M31), which is our closest neighboring spiral galaxy. M110 is one of the largest dwarf galaxies in the Local Group, a cluster of galaxies that includes the Milky Way and Andromeda.

Discovered by Charles Messier

Messier 110 was discovered by the renowned French astronomer Charles Messier on August 10, He cataloged it as the 110th entry in his list of “nebulous objects” to help fellow astronomers differentiate them from comets.

A Member of the Messier Catalog

Messier 110 is part of the famous Messier catalog, a compilation of 110 astronomical objects that includes galaxies, nebulae, and star clusters. The catalog was created by Charles Messier to aid comet hunters in their observations.

A Dwarf Elliptical Galaxy

Messier 110 belongs to the category of dwarf elliptical galaxies. These galaxies are small and feature a smooth, elongated shape. They lack the spiral arms and prominent structure seen in larger galaxies like the Milky Way and Andromeda.

Massive Size

Despite being classified as a dwarf galaxy, M110 is larger than it appears. It has a diameter of about 21,000 light-years, making it roughly 1/14th the size of the Andromeda Galaxy. Its mass is estimated to be about 1/30th the mass of the Milky Way.

Irregular Shape

Messier 110 is not a perfect ellipse. Its shape is irregular, and it exhibits asymmetry in its structure. This irregularity is likely due to interactions with its neighboring galaxies, including the massive Andromeda Galaxy.

Rich in Globular Clusters

M110 is home to a significant number of globular clusters. These dense, spherical collections of stars orbit around the center of the galaxy. The presence of globular clusters suggests that M110 has experienced multiple episodes of star formation throughout its history.

A Stash of X-ray Sources

Messier 110 has been found to harbor a large number of X-ray sources. These sources are believed to be binary star systems that consist of a compact object, such as a black hole or a neutron star, accreting matter from a companion star. The high density of X-ray sources in M110 makes it a fascinating target for X-ray observations.

A Satellite in Motion

M110 is not a stationary object. It is currently moving toward the Andromeda Galaxy at a rate of approximately 192 kilometers per second. This motion, known as proper motion, occurs due to the gravitational interactions between the two galaxies.

Potential Collision Course

In about 4 billion years, the Andromeda Galaxy and the Milky Way are expected to collide and merge. M110 will also be part of this cosmic collision, being drawn into the gravitational dance between the two galaxies. This event will reshape the structure of all three galaxies involved.

The Symbiotic Relationship with Andromeda

M110 plays an essential role in the study of the Andromeda Galaxy. As a satellite galaxy, it provides valuable insights into the formation, evolution, and dynamics of its larger companion. Researchers use observations of M110 to better understand the complex interactions between satellite galaxies and their hosts.

Home to Variable Stars

Messier 110 hosts various types of variable stars within its stellar population. These stars fluctuate in brightness over time due to internal processes such as pulsation or eruptions. Studying the behavior of variable stars in M110 helps astronomers refine their understanding of stellar evolution and the physical properties of galaxies.

Tidal Effects from Andromeda

The gravitational pull exerted by the Andromeda Galaxy has had a significant impact on MThe tidal forces experienced by M110 result in the stretching and distortion of its outer regions. This phenomenon contributes to the irregular shape and asymmetry observed in the galaxy.

A Distant Neighbor

Messier 110 is located at a distance of approximately 2.7 million light-years from Earth. While this distance may seem vast, it is relatively close in cosmic terms. Observations of M110 provide astronomers with an opportunity to study the properties of galaxies beyond our immediate cosmic neighborhood.

Stars in a Halo

M110’s stellar population is primarily concentrated in a diffuse halo surrounding its central core. This halo consists of older stars that have likely formed early in the galaxy’s history. The presence of this halo is indicative of a galaxy that has experienced multiple generations of star formation.

Subdued Star Formation

Compared to its larger companion, the Andromeda Galaxy, M110 exhibits much lower levels of ongoing star formation activity. The lack of prominent star-forming regions suggests that the galaxy has exhausted a significant portion of its gas reservoir, limiting its ability to form new stars.

A Cosmic Beacon

Messier 110, along with the Andromeda Galaxy, serves as a beacon of hope in the vast cosmos. Their close proximity to our own galaxy presents an opportunity for future intergalactic exploration and potential colonization as our understanding of space travel evolves.


In conclusion, Messier 110 (M110) is a fascinating object in the universe that continues to astound scientists and astronomers alike. With its unique characteristics, such as its elliptical shape, dense core, and rich population of globular clusters, M110 offers valuable insights into the formation and evolution of galaxies.

Exploring M110 can shed light on the intricate interplay between dark matter, supermassive black holes, and stellar populations within a galaxy. Its proximity to our own Milky Way provides an invaluable opportunity for detailed observations and further scientific discoveries.

As we delve deeper into the secrets of Messier 110 and continue to unlock its mysteries, we can only marvel at the vastness and complexity of the universe. M110 serves as a constant reminder of the wonders that await our exploration and the boundless knowledge that lies beyond.


1. What is Messier 110?
Messier 110, also known as M110 or NGC 205, is a dwarf elliptical galaxy located in the constellation Andromeda. It is part of the Local Group, which includes our own Milky Way galaxy.

2. How far away is Messier 110?
Messier 110 is located approximately 2.9 million light-years away from Earth. Its proximity makes it a prime target for scientific observation and study.

3. What makes Messier 110 unique?
One of the unique features of Messier 110 is its elliptical shape. Unlike spiral galaxies, such as the Milky Way, M110 lacks distinct spiral arms and instead appears as a smooth, elongated structure.

4. Are there any notable objects in Messier 110?
Messier 110 is known for its dense core, which harbors a large population of globular clusters. These clusters are tightly packed groups of hundreds of thousands of stars, providing valuable insights into the formation and dynamics of galaxies.

5. Can Messier 110 be seen with the naked eye?
No, M110 is not visible to the naked eye due to its distance and relatively low brightness. It requires a telescope to observe and appreciate its features.

6. What is the significance of studying Messier 110?
Studying Messier 110 offers valuable insights into the process of galaxy evolution. By analyzing its stellar populations, dark matter distribution, and interaction with other galaxies, scientists can better understand the mechanisms that shape the universe.