M87 & the Virgo Cluster – A Wide-Field View

Key Field Data

Main object: M87 – Virgo A
Region: Virgo Cluster
Constellation: Virgo
Distance to M87: approximately 54 million light-years
M87 type: giant elliptical galaxy – E0/E1
Other designations: NGC 4486, Virgo A, 3C 274
Virgo Cluster: more than 1,000 known member galaxies
Notable feature: Markarian’s Chain
M87 central black hole: approximately 6.5 billion solar masses
Historical significance: first black hole ever directly imaged
Light-travel time from M87: approximately 54 million years

Description

This wide-field image looks deep into the Virgo Cluster, the nearest major cluster of galaxies to the Milky Way.

Unlike a photograph dominated by a single large galaxy, this field is remarkable for the sheer number of galaxies visible simultaneously. Elliptical, spiral, lenticular and edge-on systems are scattered throughout the image, ranging from bright Virgo Cluster members to tiny galaxies much farther in the background.

Near the centre of the field lies M87, one of the most massive galaxies in the local Universe and the dominant giant elliptical at the heart of one of the Virgo Cluster's principal subgroups.

The wide field provided by the RedCat 51 transforms the image into something resembling a small survey of the extragalactic sky: almost everywhere one looks carefully, another galaxy appears.

M87 – A Giant Elliptical Galaxy

M87 looks very different from familiar spirals such as M31, M51 or M101.

Rather than displaying spiral arms, dust lanes and a flattened disc, it appears as a large, smooth, almost spherical glow. M87 is a giant elliptical galaxy, containing an enormous population of predominantly older stars.

It is also surrounded by an extraordinary system of globular clusters. Whereas the Milky Way contains roughly 150–200 known globular clusters, M87 possesses many thousands.

But the most famous object associated with M87 cannot be distinguished directly in this wide-field photograph: the supermassive black hole at its centre.

The First Black Hole Ever Imaged

In 2019, M87 became one of the most famous galaxies in astronomy when the Event Horizon Telescope released the first direct image of the immediate environment surrounding a black hole.

The black hole, known as M87*, has a mass of approximately 6.5 billion Suns.

The famous orange ring did not show the black hole itself — a black hole emits no light — but radiation from extremely hot material surrounding the dark central shadow.

The observation required a network of radio telescopes distributed across Earth and effectively combined into a virtual telescope approximately the size of our planet.

It is remarkable to consider that the apparently modest diffuse galaxy visible in this wide-field photograph contains the object that gave humanity its first direct view of a black hole's shadow.

A Jet Thousands of Light-Years Long

M87's central black hole also powers an extraordinary relativistic jet.

Material falling towards the black hole forms an accretion flow, while magnetic fields channel part of the surrounding plasma into a narrow beam travelling outward at velocities close to the speed of light.

The visible jet extends for several thousand light-years, while radio observations reveal structures on still larger scales.

At the image scale of the RedCat, the jet is not the principal visual feature of M87, but physically it makes the galaxy one of the most energetic objects in this entire field.

The Virgo Cluster

M87 is only one member of an enormous galactic community.

The Virgo Cluster contains well over a thousand known galaxies bound together by gravity and spread across several million light-years of space. It includes giant ellipticals, large spirals, lenticular galaxies and huge numbers of dwarf systems.

The cluster itself is not a perfectly compact or uniform structure. It contains several concentrations and subgroups that are still dynamically evolving.

Our own Local Group, containing the Milky Way, Andromeda and M33, lies far outside the Virgo Cluster. Both, however, belong to the much larger cosmic environment of galaxy groups and clusters that surrounds us.

This image therefore moves astronomy to a scale far beyond individual galaxies: it shows part of an entire galaxy cluster.

Markarian’s Chain

One of the most fascinating structures in the field is Markarian’s Chain, visible toward the lower-right region of the photograph.

It is a graceful curved arrangement of galaxies that appears to form a chain across the sky. Several of its most famous members include M84, M86, NGC 4435 and NGC 4438, together with other galaxies continuing the apparent arc.

The chain is named after Armenian astrophysicist Benjamin Markarian, who recognised that several of these galaxies share a common motion through space.

Not every galaxy appearing along the visual chain necessarily occupies exactly the same position in three-dimensional space, but several are physically related members of the Virgo Cluster.

In a closer image each would be an interesting target in its own right. Here they become components of a much larger cosmic landscape.

A Field Where Almost Every Smudge Is a Galaxy

The most impressive aspect of this image becomes apparent when it is examined at full resolution.

Many objects that initially resemble faint stars or tiny patches of noise reveal themselves as distant galaxies. Some are smooth and elliptical, others are thin edge-on discs, while several clearly show spiral structure.

The larger and brighter systems predominantly belong to the Virgo Cluster, but many of the smallest objects lie much farther behind it.

Foreground stars from the Milky Way are also present, identifiable by their point-like appearance and, for the brighter examples, diffraction patterns.

This creates a remarkable hierarchy: individual foreground stars occupy the nearest layer, the Virgo galaxies form a vast concentration roughly 50–60 million light-years away, and still more distant galaxies extend the view hundreds of millions of light-years into the background.

A Glimpse of the Cosmic Web

Galaxy clusters such as Virgo are among the largest gravitationally bound structures in the Universe.

Galaxies are not distributed randomly through space. They gather into groups, clusters, filaments and vast sheets separated by enormous cosmic voids, forming what astronomers call the cosmic web.

The Virgo Cluster is part of this much larger architecture.

A wide-field photograph cannot reveal the entire three-dimensional cosmic web directly, but this concentration of galaxies provides an immediate visual indication that galaxies tend to gather into enormous structures rather than being uniformly scattered throughout space.

The apparently crowded field is therefore the visible surface of a much larger structure extending millions of light-years in depth.

Looking Back in Time

The light reaching us from M87 has travelled for approximately 54 million years.

When those photons left the galaxy, Earth was in the Eocene epoch. The non-avian dinosaurs had already disappeared, mammals were diversifying rapidly, and human beings were still tens of millions of years in the future.

The other Virgo Cluster galaxies are seen at broadly comparable epochs, although their actual distances vary substantially across the cluster.

The smallest background galaxies tell a much older story. Some may lie hundreds of millions of light-years away, so their light began travelling towards Earth long before the light we now receive from M87.

This single photograph therefore contains not one moment of cosmic history, but many — layered one behind another across an enormous depth of space.

Image Data

Total integration time: 5h 24m

Integration by filter:

  • L-Pro: 1h 54m (38 × 180")

  • Red: 1h 36m (32 × 180")

  • Green: 1h (20 × 180")

  • Blue: 54m (18 × 180")

Equipment:

  • Telescope: William Optics RedCat / Cat 51 III WIFD

  • Camera: ToupTek ATR2600M

  • Mount: 10Micron GM2000 HPS II

  • Filters: Optolong Blue 2", Optolong Green 2", Optolong L-Pro 2", Optolong Red 2"

  • Accessories: ToupTek AAF Electric Focuser, WandererAstro WandererCover V4-EC

  • Software: Adobe Photoshop, Pleiades Astrophoto PixInsight, Stefan Berg Nighttime Imaging 'N' Astronomy (N.I.N.A. / NINA)

For further details and the full-resolution image, visit AstroBin:

View M87 & the Virgo Cluster on AstroBin