Planetary Nebula - Ha - What are they good for ?"

 

M57 The Ring Planetary Nebula
in the constellation Lyra. Imaged by: Pip Stakkert from the JPO
using the Meade 127mm Apo Refractor and the Canon 600d DSLR

M27 The Dumbbell Planetary Nebula
in the constellation Vulpecula. Imaged by: Kurt Thrust from the JPO
using the Meade 127mm Apo Refractor and the Canon 600d DSLR

M76 The Little Dumbbell or Cork Planetary Nebula in the constellation Perseus.
Image created, curated and processed by Kurt Thrust.
Data Credit: COAST Robotic Telescope, Teneriffe.
telescope.org Open Observatories, Open University.

M97 The Owl Planetary Nebula 
in the constellation Ursa Major
Image created, curated and processed by Kurt Thrust.
Data Credit: PIRATE Robotic Telescope, Teneriffe.
telescope.org Open Observatories, Open University.

" The Observatory sponsors recently invested in RC -Astro's excellent 'NoiseXTerminator' plug in for the Affinity Photo 2.65 software, which we use as our core photo editor at the Jodrell Plank Observatory. So the team decided to test it on a selection of images we always considered 'noisy'.

Kurt also thought that Planetary Nebulae had not been featured that often in previous posts and very little had been said about these small and intriguing objects, which irrespective of their generic collective name have absolutely nothing to do with planets" - Joel Cairo CEO of the Jodrell Plank Observatory.

"Observation Report: A Comparative Study of Planetary Nebulae — M57, M27, M76, and M97

Among the most striking celestial objects captured by amateur and professional astronomers alike are the planetary nebulae — delicate, luminous shells of gas cast off by dying stars. Despite their name, these nebulae have nothing to do with planets; the term originates from their round, planet-like appearance in early telescopes. In reality, they represent a fleeting but beautiful phase in stellar evolution, a brief transition between the red giant and white dwarf stages.

Planetary nebulae mark the final breaths of Sun-like stars — those with masses up to roughly eight times that of our Sun. After spending billions of years fusing hydrogen into helium, such a star exhausts its nuclear fuel and swells into a red giant. In its unstable outer layers, pulsations and stellar winds drive away the star’s atmosphere, leaving behind an exposed core. The remnant, an intensely hot white dwarf, bathes the ejected gases in ultraviolet light, causing them to glow in intricate patterns and vivid colors. This process lasts only a few tens of thousands of years — a mere instant in cosmic time — before the nebula dissipates into the interstellar medium. One day, our own Sun will undergo this transformation, shedding its outer layers to illuminate the space once occupied by the Solar System with a faint, spectral glow.

The images presented here — of M57, M27, M76, and M97 — showcase four distinct manifestations of this same underlying process, each a variation on the theme of stellar death and renewal.

M57 — The Ring Nebula in Lyra appears as a nearly perfect oval, a smoke ring suspended against the velvet backdrop of the constellation Lyra. Its symmetry and sharply defined edges make it one of the most iconic planetary nebulae. The bright ring traces dense gas expanding at about 20 km/s, while the interior is filled with a fainter, ionized glow. The white dwarf at its heart shines with a temperature exceeding 100,000 K, illuminating the nebula like a hidden ember lighting a cloud of dust.

M27 — The Dumbbell Nebula in Vulpecula contrasts sharply with M57’s geometric simplicity. Instead of a ring, M27 displays a complex hourglass shape, the result of gas escaping along preferred directions in the star’s equatorial and polar regions. Its relatively large apparent size and brightness make it a favorite target for both observers and imagers. The vivid greens and reds often seen in photographs arise from doubly ionized oxygen and hydrogen-alpha emissions, respectively — spectral fingerprints of the nebula’s composition and excitation.

M76 — The Little Dumbbell Nebula in Perseus presents a more turbulent visage. Its bipolar structure resembles a miniature version of M27 but appears denser and more irregular, suggesting strong stellar winds or interactions between successive shells of ejected gas. Often described as one of the faintest Messier objects, M76 rewards deep exposures with intricate filaments and knots that hint at the chaotic processes shaping planetary nebulae.

Finally, M97 — The Owl Nebula in Ursa Major takes its name from the ghostly “eyes” visible in long-exposure images, dark cavities within an otherwise round shell. Its soft, diffuse glow and subtle color palette contrast with the crisp outlines of M57, giving it a tranquil, almost meditative appearance. The symmetry of M97 suggests a more isotropic mass loss, a calm exhalation of stellar material compared to the more directional outflows of M27 and M76.

Together, these four nebulae form a kind of evolutionary gallery — each a testament to the diversity of outcomes when stars of similar mass approach the end of their lives. Differences in mass, composition, rotation, and surrounding environment sculpt each nebula into a unique shape, much as individual personalities imprint themselves on human lives.

For the casual observer, planetary nebulae may seem serene and static, but in truth they are dynamic, expanding, and evolving. The gas we see today will, in a few millennia, blend into the cosmic medium, seeding new stars and planets. In this sense, planetary nebulae are not symbols of death, but of transformation — reminders that the material of stars, including that of our own Sun, ultimately returns to the galaxy to begin anew". Professor G.P.T Chat visiting astrophysicist at the JPO.

The Comet C:/2025 A6 (Lemmon)

 

Comet C:/2025 A6 (Lemmon) imaged by Kurt Thrust at the JPO
on the 21st October 2025
using a fixed tripod mounted Canon 600d DSLR
 with a 135mm F2 Samyang lens. Stacks of 10x5 sec subs at ISO 1600.

" Kurt was very lucky to capture some short exposure subs of the Comet C/2025 A6 (Lemmon) from the approach road to the Jodrell Plank Observatory, on the 21st October 2025. In the early evening twilight and amongst the clouds and light pollution, the comet was extremely difficult to see with the naked eye. It was located very low in the north west and to the west of the bright star Arcturus, which Kurt used as a guide. In such circumstances it is very useful to have the Stellarium App on your smartphone! 

Bearing in mind the shortness of the sub exposures a reasonable amount of detail can be seen in Kurt's two stacked images. Close inspection reveals: a small green coma around the comet nucleus, separate ion and dust clouds and some disturbance in the fainter part of the ion tail created by the current strong solar wind". - Joel Cairo CEO of the Jodrell Plank Observatory.

"Comet C/2025 A6 (Lemmon) is a long-period comet discovered on 3 January 2025 by the Mount Lemmon Survey at Mount Lemmon, Arizona. 

 It is notable for its striking greenish coma and its relatively rare visit to the inner Solar System, offering a “once-in-a-millennium” viewing opportunity.

Orbital and Physical Characteristics:

Perihelion distance (q): ~0.5299 AU from the Sun.

Closest approach to Earth: ~0.596 AU (~89 million km) on 21 October 2025. 

Orbital eccentricity: approximately 0.9957 (inbound) indicating a very elongated trajectory. 

Inclination: ~143.66° relative to the ecliptic. 

Estimated orbital period before perturbations: ~1,350 years. 

The comet’s coma displays a green hue, attributed to diatomic carbon (C₂) fluorescing under solar ultraviolet radiation. 

Observational History and Brightness Evolution:

Upon discovery, the comet had a magnitude of ~21.6 while at ~4.5 AU from the Sun. 

 As it moved inward, its brightness increased more rapidly than initially predicted, making it an excellent target for astrometric monitoring and public sky-watching.

By late September and early October 2025, the comet’s magnitude had improved to around +8 to +6.6, with a visible ion tail several degrees long in photographs. 

 Projections suggested it might reach magnitudes around +3.5 to +4 at closest approach — potentially visible to the naked eye under dark skies. 

Coma and Tail Morphology:

The nucleus of the comet is surrounded by a diffuse coma of sublimated ices and entrained dust. As the comet approached perihelion, solar heating drove the sublimation of volatile ices, producing jets and releasing dust particles. These created a dual-tail structure:

An ion tail, composed of ionised gas interacting with the solar wind, giving a straight, bluish or greenish stream pointing away from the Sun. 

A dust tail, composed of larger dust grains lagging behind the nucleus, giving a broader, more curved appearance. 

On 2 October 2025, a tail‐disconnection event was reported — a phenomenon where part of the ion tail is severed by a magnetic shock in the solar wind. 

Significance and Future Return:

Because of its long period and highly elongated orbit, Comet Lemmon is not expected to return for ~1,000 years or more — making this passage effectively a once-in-a-human-lifetime event. 

 Moreover, its green coma offers both aesthetic and scientific interest: the chemistry of C₂ and other radicals in cometary comae is a window into the pristine ices preserved since the Solar System’s formation.

Viewing Circumstances (for Northern Hemisphere):

From mid- to late October 2025, the comet became progressively favourably placed in the evening sky. It moved through constellations such as Boötes and Serpens, and at its peak was visible at solar elongations of ~30-40°. 

 Observers are advised to look from a dark site, away from light pollution, and employ binoculars or small telescopes to first locate the object; naked-eye spotting is possible under very good conditions. 

Scientific Importance:

Comets such as C/2025 A6 (Lemmon) are fragments from the outer Solar System (likely the Oort Cloud) that are only occasionally perturbed into the inner region. Studying their composition, dust and gas production rates, and response to solar heating helps refine models of Solar System evolution, volatile delivery to the terrestrial planets, and the dynamics of cometary orbits. Moreover, morphological changes (such as tail disconnection events) provide in situ diagnostics of the solar wind–comet interaction.

Summary:

Comet C/2025 A6 (Lemmon) presents a rare observational opportunity: a long‐period comet with a greenish coma, brightening unexpectedly to visibility, and approaching within ~0.6 AU of Earth in October 2025, with perihelion at ~0.53 AU in November. Its highly elongated orbit, infrequent return, and the dual‐tail morphology make it both a compelling target for amateur and professional astronomers, and a valuable subject for cometary science". Professor G.P.T. Chat visiting astrophysicist at the Jodrell Plank Observatory.

Star cluster in the heart of the Rosette - NGC 2244

 

NGC 2244, Open Star cluster in the Rosette Nebula located in the constellation Monoceros the Unicorn.
Data credit: COAST robotic telescope - SHO filters - blended Sll and Ha for luminance, telescope org. Open Observatories, Open University.
Image Credit: Kurt Thrust at the JPO.

" The Essex based astroimager, Nik Szymanek , has been writing an interesting series of articles in the magazine Astronomy Now, showcasing the ways in which SHO palette images may be processed using the Sll and Ha data as a synthetic luminance layer. I was much intrigued with this idea and and wondered if the Rosette Nebula might respond well to using a blended Sll and Ha synthetic luminance layer. The particular blend I used accentuated Sll (ionised sulphur}over and above the Ha (Hydrogen alpha) content. I believe this image processing method has made for the more dramatic photograph above" - Kurt Thrust current Director of the Jodrell Plank Observatory. 

The Rosette Nebula; Seestar S30 with Dual Band nebula filter, 
flipped vertically to match orientation with the top detail image 
Processed to emphasise the H alpha component of the image.
Image Credit: Pip Stakkert at the JPO

The Rosette Nebula; Seestar S30 with Dual Band nebula filter,
flipped vertically to match orientation with the other images .
Processed to emphasise the 3 dimensional nature of the nebula
with reduced emphasis on the H alpha component of the image.
Image Credit: Pip Stakkert at the JPO

A Brief Report on the Open Cluster NGC 2244 and Ionised Gas in the Rosette Nebula

The open star cluster NGC 2244 is located at the centre of the Rosette Nebula (Caldwell 49), a large H II region in the constellation Monoceros, at an approximate distance of 1.5–1.6 kiloparsecs (about 5,000 light-years) from the Sun. The cluster has an estimated age of 2–6 million years and is composed primarily of young, massive O- and B-type stars. These hot, luminous members are the principal sources of the nebula’s ionisation and play a dominant role in shaping its morphology through intense ultraviolet radiation and stellar winds.

The energetic radiation field of NGC 2244 drives a strong ionisation front, producing extensive emission in the H α (656.3 nm) recombination line of hydrogen, characteristic of classical H II regions. The nebula’s interior exhibits strong [O III] (495.9 and 500.7 nm) emission, arising from doubly ionised oxygen in regions of higher excitation closer to the cluster core. In contrast, [S II] (671.6 and 673.1 nm) lines are more prevalent along the periphery of the nebula and in dense ionisation fronts, where lower excitation and partially ionised zones are found.

The spatial distribution of these emission lines delineates the stratified ionisation structure typical of massive star-forming regions: [O III] tracing the hottest, most highly ionised gas; H α marking the main ionised hydrogen volume; and [S II] outlining the transition to neutral material. Together, these diagnostics reveal the ongoing interaction between the cluster’s massive stars and their natal molecular cloud, providing a detailed view of stellar feedback processes in early cluster evolution. - Professor G.P.T Chat visiting astrophysicist at the Jodrell Plank Observatory.

"And now for something completely different"

 

The Double Quasar in the Constellation Ursa Major. Data Credit: the COAST robotic telescope, BVR filters, Tenerife. telescope.org. Open Observatories, Open University. Image Credit: Kurt Thrust at the JPO.

" I was going through the JPO archive of data obtained via Open Observatories and discovered that in February 2024, my friend Kurt Thrust had programmed the COAST robotic telescope to image two Quasars. A quasar is an extremely luminous, active galactic nucleus powered by a supermassive black hole at the center of a distant galaxy. As gas and dust fall into the black hole, they form a superheated accretion disk that emits massive amounts of energy across the electromagnetic spectrum, often outshining its host galaxy. These objects can also produce powerful jets of radiation and are among the brightest objects in the universe. The 'Double Quasar in Ursa Major, is remarkable in that in reality it is one object that appears as two because of gravitational lensing. 

The Double Quasar and Neighboring Galaxies in Ursa Major

 The Double Quasar (Q0957+561)

The object known as Q0957+561, often referred to as the Double Quasar, is one of the most celebrated examples of gravitational lensing in extragalactic astronomy. It resides in the constellation Ursa Major, at a redshift of z ≈ 1.41, corresponding to a light-travel distance of roughly 8.7 billion light-years.

What makes Q0957+561 remarkable is its appearance as two nearly identical quasar images separated by about 6 arcseconds on the sky. These twin images  are not two distinct quasars, but rather light from a single background quasar that has been gravitationally lensed by an intervening galaxy and its surrounding cluster of galaxies at z ≈ 0.36. The foreground lensing galaxy, a massive elliptical designated G1, lies directly between the two quasar images.

The Double Quasar
showing the lensing galaxy cluster
image credit: ESA/Hubble

This system provided the first confirmed case of gravitational lensing of a quasar, discovered in 1979 by Dennis Walsh, Robert Carswell, and Ray Weymann. The discovery confirmed one of the key predictions of Einstein’s general theory of relativity: that massive bodies curve spacetime sufficiently to split and magnify light from background sources.

Subsequent long-term monitoring of the Double Quasar has revealed a measurable time delay of about 417 days between variations in brightness of the two images. This delay arises because the two light paths have slightly different lengths and traverse different gravitational potentials. Measurement of this delay has been used to estimate cosmological parameters such as the Hubble constant, making Q0957+561 a cornerstone object in observational cosmology.

At the eyepiece, Q0957+561 is an extremely faint object of approximately magnitude 16.5, appearing star-like even in large amateur telescopes. Only with high-resolution imaging or long-exposure CCD observations can the twin images be resolved.

NGC 3079

Located roughly 10 arcminutes south of Q0957+561, NGC 3079 is a striking edge-on spiral galaxy in Ursa Major, at a distance of about 50 million light-years (z ≈ 0.0037). Classified as type SBc, it exhibits a strong central starburst and nuclear activity, often cited as an example of a Seyfert 2 or LINER galaxy.

High-resolution imaging reveals a prominent dust lane bisecting its stellar disk and a biconical outflow of hot gas extending several kiloparsecs from the nucleus. X-ray and radio observations indicate the presence of superbubbles and galactic-scale winds driven by intense star formation and possibly a weak active nucleus. NGC 3079 is therefore a laboratory for studying feedback processes between star formation, black hole activity, and the interstellar medium.

n small telescopes, NGC 3079 appears as a slender, elongated streak of light—an impressive edge-on system that offers a vivid contrast to the much more distant and exotic Double Quasar nearby on the sky.

 NGC 3703

Farther east in Ursa Major lies NGC 3703, a relatively faint spiral galaxy (type Sc) situated at a distance of approximately 90–100 million light-years. With an apparent magnitude near 12.8, it is considerably fainter and less studied than NGC 3079. Its disk shows loosely wound spiral arms and moderate star-forming activity. NGC 3703 belongs to the same general region of the sky as the Ursa Major Cluster of galaxies, though it may lie slightly in the background relative to the cluster’s core.

While lacking the dramatic features of NGC 3079 or the cosmological significance of the Double Quasar, NGC 3703 serves as a representative example of a normal, late-type spiral galaxy, offering a useful photometric and spectroscopic comparison to more active systems in the same constellation.

Astronomical Context

• The region of Ursa Major containing Q0957+561 and NGC 3079 is an area of considerable astrophysical diversity. Within a single degree of sky, one can observe:
• A galaxy-scale gravitational lens probing the structure of spacetime and the expansion of the universe;
• A starburst galaxy exhibiting large-scale feedback and nuclear outflows; and
• A normal spiral system representative of the quiescent star-forming population.

Together, these objects demonstrate the richness of extragalactic phenomena observable in a single patch of the northern sky — from the nearby universe of tens of millions of light-years to the deep cosmos nearly nine billion years in the past.

Distance to the Double Quasar Q0957+561

• Redshift (z): ≈ 1.41

This redshift means the light we see from the quasar left it when the universe was much younger — less than half its current age.

Using the latest ΛCDM cosmological parameters (H₀ = 70 km s⁻¹ Mpc⁻¹, Ωₘ = 0.3, ΩΛ = 0.7), we can derive several commonly used distance measures:

Distance Type	Value	Meaning
Light-travel time distance	≈ 8.7 billion light-years	How long the photons have been en route to us.
Comoving radial distance	≈ 9.3 billion light-years	The current proper distance to where the quasar is now, accounting for cosmic expansion.
Luminosity distance	≈ 10.6 billion light-years	Used in converting apparent to absolute brightness, factoring in redshift dimming.

Thus, the Double Quasar is among the most distant objects visible in amateur-sized telescopes — you are seeing it as it appeared when the universe was only about 4.5 billion years old, roughly one-third of its current age.

Foreground lens galaxy

The massive elliptical galaxy G1, which lenses the background quasar, has a redshift of z ≈ 0.36, corresponding to a light-travel time of about 4.0 billion light-years.

The geometry of these two distances — a lens about halfway between us and the quasar — is what produces the beautiful and scientifically rich double image observed as Q0957+561 A and B.

In summary:

Q0957+561 lies roughly 8.7 billion light-years away, making it one of the farthest celestial objects ever discovered by purely optical means and the first gravitationally-lensed quasar confirmed in human history."

 - Karl Segin  outreach co-ordinator at the JPO and Professor G.P.T Chat.

The Double Cluster re-visited

 

The Double Cluster - NGC 869 and NGC 884. Modded Canon 200d DSLR with Dual Band Filter and 135mm Samyang Lens.

Map Credit: freestarcharts.com

" Both Kurt and Pip have never believed that they have done the Double Cluster justice. When you look at this pair of open star clusters, through binoculars or a widefield eyepiece on  a telescope at low magnification, it is truly magnificent.  The Double Cluster, viewed through the JPO's tripod mounted 11x80mm.binoculars, is a joy to see in its jewel like appearance. If you have a pair of binoculars and it's a clear night in the Northern Hemisphere, why not try and find it between Cassiopeia and Perseus? - Joel Cairo CEO of the Jodrell Plank Observatory.

"The Double Cluster in Perseus, catalogued as NGC 869 and NGC 884, is a striking pair of young, massive open star clusters located in the Perseus arm of the Milky Way Galaxy. Situated at an approximate distance of 7,500 light-years (2.3 kpc) from Earth, the system lies within the Perseus OB1 association, an active star-forming region rich in hot, luminous stars.

Both clusters are estimated to be relatively young, with ages on the order of 12–14 million years, placing them in a comparable evolutionary stage. Their stellar populations are dominated by early-type B-class main-sequence stars and a notable complement of evolved blue and red supergiants, evidence of rapid stellar evolution in high-mass stars. Integrated spectral analyses indicate a near-solar metallicity, consistent with their origin in a typical Galactic spiral-arm environment.

The clusters are physically separated by only a few hundred light-years, suggesting a common origin from the same giant molecular cloud. Their projected angular separation on the sky is approximately 30 arcminutes (roughly the apparent diameter of the full Moon), making them easily distinguishable yet visually connected in telescopic and binocular observations.

Photometric studies of NGC 869 and NGC 884 reveal high stellar densities in their cores, with mass estimates of several thousand solar masses each, placing them among the most massive open clusters in the Milky Way. Their combined luminosity and concentration of bright, blue stars make the Double Cluster an archetypal laboratory for studying the early dynamical evolution of clustered stellar populations.

Owing to their brightness (apparent magnitudes ~+4.3 and +4.4) and their location near the Perseus–Cassiopeia border, the Double Cluster has been recognized since antiquity, though it was first catalogued systematically by Hipparchus around the 2nd century BCE. Today, the system remains a prominent observational target for both professional astrophysical research and amateur astronomy, offering insight into star cluster formation, stellar evolution, and Galactic structure". - Professor G.P.T. Chat visiting astrophysicist at the Jodrell Plank Observatory.

The Heart of the matter

 

IC 1805 and Melotte 15.

"The above images captured at the Jodrell Plank Observatory and also by the PIRATE robotic telescope on Mount Teide, Tenerife (credit telescope .org, Open Observatories, Open University) show the Heart Nebula, IC1805 in increasing detail and reducing field of vision. The top, widefield image was captured with the JPOs modded Canon 200d Camera with a Dual Band filter and a Samyang 135mm lens. The other two were captured by the PIRATE telescope with SHO filters. Pip Stakkert used a number of processing techniques to emphasise the nebulosity". - Kurt Thrust current Director of the JPO.

"The Heart Nebula (IC 1805) is a large emission nebula located in the Perseus Arm of the Milky Way, within the constellation Cassiopeia. At an estimated distance of approximately 6,000–7,500 light-years from Earth, it extends over nearly 200 light-years in diameter, making it one of the more prominent star-forming complexes in the northern sky. Its common name derives from the overall morphology of its extended H II region, which, in wide-field optical images, presents an outline reminiscent of a stylized human heart.

The nebula is primarily excited by the young stellar population of the open cluster Melotte 15, situated near the nebula’s center. This cluster, containing numerous hot O-type and early B-type stars, serves as the dominant ionizing source for the surrounding gas. The intense ultraviolet radiation emitted by these massive stars ionizes the hydrogen in the surrounding molecular cloud, producing the characteristic red glow of Hα emission. Stellar winds and radiation pressure also drive large-scale feedback processes that shape the morphology of the nebula, generating bright ridges, cavities, and dark, pillar-like structures of dense gas.

Of particular note is the brighter nebulosity concentrated near the nebula’s core. This region surrounds Melotte 15 and exhibits a higher surface brightness due to the proximity of the ionizing sources and the resulting density contrast between ionized and neutral gas. Within this core, the interplay between radiation, stellar winds, and turbulence has carved out intricate filaments and luminous fronts, where shock compression has enhanced local gas densities. These conditions are conducive to ongoing star formation: observations at infrared and radio wavelengths reveal embedded protostars and compact H II regions tracing younger generations of stellar objects still enshrouded in dust.

In summary, IC 1805 exemplifies the dual role of massive stars in galactic ecology: while their radiation and winds sculpt and erode the parent molecular cloud, they also trigger subsequent episodes of star formation. The central bright nebulosity of the Heart Nebula, therefore, represents not only a visually striking concentration of emission but also the dynamic hub of stellar feedback and continuing stellar genesis within the complex". -Professor G.P.T Chat and Karl Segin outreach coordinator at the JPO.

The Iris Reflection nebula in the constellation Cepheus

The Iris Nebula in modified SHO format. The PIRATE Robotic Telescope,Mount Teide, Teneriffe.   Data Credit: telescope.org. Open Observatories, Open University. Image Credit: Kurt Thrust.

" Kurt was feeling a little better today and so he and the JPO engineer, Jolene McSquint-Fleming, were busy remaking a diffraction grating for the Seestar S30. They decided to make a grating, which covers the full aperture of the little scope rather than  partially. It will be interesting to see whether this affects the accuracy of the scope's guidance and goto software". - Joel Cairo CEO at the JPO.

The new-recycled magnetic 50 lines/mm
full aperture grating for the Seestar 30

Spectrum produced by the above grating
using the JPO Visitor Centre door security peep hole
as an artificial star.

" If we get a clear night soon, we will try the new grating out and develop a capture process, which enables the removal of stars and hot spots, which otherwise corrupt the  target and calibration spectra". - Kurt Thrust current Director of the JPO.

" The Iris Nebula, cataloged as NGC 7023, is a bright reflection nebula located in the constellation Cepheus, approximately 1,300 light-years from Earth. It is a striking example of a dust cloud illuminated by starlight rather than by its own emission. At its center lies a young, hot star designated HD 200775, whose intense blue-white radiation reflects off surrounding interstellar dust grains. This scattering process preferentially reflects shorter wavelengths, giving the nebula its characteristic bluish hue, much like the mechanism that makes Earth’s sky appear blue.

The nebula spans roughly six light-years across and is embedded within a larger molecular cloud complex. Its structure reveals striking contrasts: bright filaments and wisps where dust strongly reflects starlight, interspersed with dark lanes where dense concentrations of material obscure illumination. Infrared observations have shown that the dust contains complex carbon-rich molecules, including polycyclic aromatic hydrocarbons (PAHs), which are thought to play a role in interstellar chemistry and may represent building blocks of more complex organic compounds.

Unlike emission nebulae, which glow due to ionized gas, the Iris Nebula remains primarily a reflection nebula because the radiation from its central star is not energetic enough to fully ionize the surrounding hydrogen gas. Instead, the nebula’s beauty lies in the interplay of light and shadow, highlighting the distribution of interstellar dust and providing astronomers with insights into the conditions of stellar nurseries". - Professor G.P.T Chat visiting astrophysicist at the Jodrell Plank Observatory.

Enlarged and cropped view of the spectacular Iris reflection Nebula