Welcome back to Messier Monday! Today, we continue in our tribute to our dear friend, Tammy Plotner, by looking at the globular cluster known as Messier 72.
During the 18th century, famed French astronomer Charles Messier noticed the presence of several “nebulous objects” while surveying the night sky. Originally mistaking these objects for comets, he began to catalog them so that others would not make the same mistake. Today, the resulting list (known as the Messier Catalog) includes over 100 objects and is one of the most influential catalogs of Deep Space Objects.
One of these objects is Messier 72, a globular cluster about 54,570 light years away in the direction of the Aquarius constellation. Originally discovered by French astronomer Pierre Méchain a few years prior, Messier would go on to include this star cluster in his catalog. Located in close proximity to Messier 73, this globular cluster is one of the smaller and fainter Messier objects in the night sky. Continue reading “Messier 72 – the NGC 6981 Globular Cluster”
Chart showing the M71 Globular Cluster. Credit: astronomycentral.co.uk
Welcome back to Messier Monday! Today, we continue in our tribute to our dear friend, Tammy Plotner, by looking at the unusual globular cluster known as Messier 71.
If you look up into the night sky, on a particularly clear night when there’s not a lot of bright lights nearby, you may be able to make out a series of faint objects. Similar to the Milky Way, that cloudy, ghostly band that reaches across the night sky, these small pockets of fuzzy light are in fact collections of stars located thousands of light years away.
The globular clusters M69 and M70, which lie in the Sagittarius Constellation. Image: Wikisky
Welcome back to Messier Monday! Today, we continue in our tribute to our dear friend, Tammy Plotner, by looking at the globular cluster known as Messier 69.
In the 18th century, while searching the night sky for comets, French astronomer Charles Messier kept noting the presence of fixed, diffuse objects he initially mistook for comets. In time, he would come to compile a list of approximately 100 of these objects, hoping to prevent other astronomers from making the same mistake. This list – known as the Messier Catalog – would go on to become one of the most influential catalogs of Deep Sky Objects.
One of these objects is known as Messier 69 (NGC 6637), a globular cluster located in the constellation Sagittarius. Located about about 29,700 light-years away from Earth, this cluster lies close to Messier 70 (both of which were discovered Charles Messier on August 31st, 1780). Both objects lie close to the galactic center, and M69 is one of the most metal-rich globular clusters known. Continue reading “Messier 69 – the NGC 6637 Globular Cluster”
The location of the King Cobra open star cluster (aka. Messier 67). Credit: Wikisky
Welcome back to Messier Monday! Today, we continue in our tribute to our dear friend, Tammy Plotner, by looking at the big snake – the King Cobra Cluster (aka. Messier 67).
In the 18th century, while searching the night sky for comets, French astronomer Charles Messier kept noting the presence of fixed, diffuse objects he initially mistook for comets. In time, he would come to compile a list of approximately 100 of these objects, hoping to prevent other astronomers from making the same mistake. This list – known as the Messier Catalog – would go on to become one of the most influential catalogs of Deep Sky Objects.
One of these objects is the open star cluster known as Messier 67, aka. the King Cobra Cluster. Located in the Cancer Constellation, and with age estimates ranging from 3.2 and 5 billion years, this cluster is one of the oldest clusters known. And at a distance of roughly 2610 and 2930 (800 – 900 pc) from Earth, it is the closest of any of the older open star clusters. Continue reading “Messier 67 – the King Cobra Open Star Cluster”
Image of the Black Eye Galaxy (Messier 64), taken with Hubble's Wide Field Planetary Camera 2 (WFPC2). Credit: NASA and The Hubble Heritage Team (AURA/STScI)
Welcome back to Messier Monday! Today, we continue in our tribute to our dear friend, Tammy Plotner, by looking at that “evil” customer known as Messier 64 – aka. the “Black Eye Galaxy”!
In the 18th century, while searching the night sky for comets, French astronomer Charles Messier kept noting the presence of fixed, diffuse objects he initially mistook for comets. In time, he would come to compile a list of approximately 100 of these objects, hoping to prevent other astronomers from making the same mistake. This list – known as the Messier Catalog – would go on to become one of the most influential catalogs of Deep Sky Objects.
One of these objects is known as Messier 64, which is also known as the “Black Eye” or “Evil Eye Galaxy”. Located in the Coma Berenices constellation, roughly 24 million light-years from Earth, this spiral galaxy is famous for the dark band of absorbing dust that lies in front of the galaxy’s bright nucleus (relative to Earth). Messier 64 is well known among amateur astronomers because it is discernible with small telescopes.
Description:
Residing about 19 million light years from our home galaxy, the “Sleeping Beauty” extends across space covering an area nearly 40,000 light years across, spinning around at a speed of 300 kilometers per second. Toward its core is a counter-rotating disc approximate 4,000 light years wide and the friction between these two may very well be the contributing factor to the huge amounts of starburst activity and distinctive dark dust lane.
Infrared image taken by the Hubble Space Telescope, which penetrated the dust clouds swirling around the centers of the M64 galaxy. Credits: Torsten Boeker, Space Telescope Science Institute and NASA/ESA
Stars themselves appear to be forming in two waves, first evolving outside following the density gradient where abundant interstellar matter was waiting, and then evolving slowly. As the material from the mature stars began beig pushed back by their stellar winds, supernovae, and planetary nebulae, increased amounts of interstellar matter once again compressed, beginning the process of star formation again. This “second wave” may very well be represented by the dark, obscuring dust lane we see.
But, M64 isn’t without it share of turmoil. Its dual rotation may have started as a collision when two galaxies merged some billion years ago – or so theory would suggest. But did it? As Robert Braun and Rene Walterbos explained in their 1995 study:
“This galaxy is known to contain two nested, counter rotating, gas disks of a few 108 solar mass each, with the inner disk extending to approximately 1 kpc and the outer disk extending beyond. The stellar kinematics along the major axis, extending across the transition region between the two gas disks, show no hint of velocity reversal or increased velocity dispersion. The stars always rotate in the same sense as the inner gas disk, and thus it is the outer disk which ‘counterrotates’. The projected circular velocities inferred from the stellar kinematics and from the H I disks agree to within approximately 10 km/s, supporting other evidence that the stellar and gaseous disks are coplanar to approximately 7 deg. This upper limit is comparable to the mass of detected counter rotating gas. This low mass of counter rotating material, combined with the low-velocity dispersion in the stellar disk, implies that NGC 4826 cannot be the product of a retrograde merger of galaxies, unless they differed by at least an order of magnitude in mass. The velocities of the ionized gas along the major axis are in agreement with that of the stars for R less than 0.75 kpc. The subsequent transition toward apparent counter rotation of the ionized gas is spatially well resolved, extending over approximately 0.6 kpc in radius. The kinematics of this region are not symmetric with respect to the galaxy center. On the southeast side there is a significant region in which vproj (H II) much less than vcirc approximately 150 km/s, but sigma (H II) approximately 65 km/s. The kinematic asymmetries cannot be explained with any stationary dynamical model, even is gas inflow or warps were invoked. The gas in this transition region shows a diffuse spatial structure, strong (N II) and (S II) emission, as well as the high-velocity dispersion. These data present us with the conundrum of explaining a galaxy in which a stellar disk, and two counter rotating H I disks, at smaller and much larger radii, appear in equilibrium and nearly coplanar, yet in which the transition region between the gas disks is not in steady state.”
So is all what it really appears to be? Are new stars being born in the darkness? As A. Majeed (et al) indicated in their 1999 study:
“The Evil Eye galaxy (NGC 4826; M64) is distinguished by an asymmetrically placed, strongly absorbing dust lane across its prominent bulge. We obtained a long-slit spectrum of NGC 4826, with the slit across the galaxy’s nucleus, covering equal parts of the obscured and the unobscured portions of the bulge. By comparing the spectral energy distributions at corresponding positions on the bulge, symmetrically placed with respect to the nucleus, we were able to study the wavelength dependent effects of absorption, scattering, and emission by the dust, as well as the presence of ongoing star formation in the dust lane. We report the detection of strong extended red emission (ERE) from the dust lane within about 15 arcsec distance from the nucleus of NGC 4826. The ERE band extends from 5400 A to 9400 A, with a peak near 8800 A. The integrated ERE intensity is about 75 % of that of the estimated scattered light from the dust lane. The ERE shifts toward longer wavelengths and diminishes in intensity as a region of star formation, located beyond 15 arcsec distance, is approached. We interpret the ERE as originating in photoluminescence by nanometer-sized clusters, illuminated by the galaxy’s radiation field, in addition to the illumination by the star-forming complex within the dust lane. When examined within the context of ERE observations in the diffuse ISM of our Galaxy and in a variety of other dusty environments such as nebulae, we conclude that the ERE photon conversion efficiency in NGC 4826 is as high as found elsewhere, but that the size of the nanoparticles in NGC 4826 is about twice as large as those thought to exist in the diffuse ISM of our Galaxy.”
Messier 64 (“Black Eye Galaxy”) imaged using amateur telescope. Credit: Jeff Johnson.
But the debate is still on. As R.A. Walterbos (et al) expressed in their 1993 study:
“The close to coplanar orientation of the gas disks is one aspect which is in good agreement with what is expected on the basis of a merger model for the counter-rotating gas. The rotation direction of the inner gas disk with respect to the stars, however, is not. In addition, the existence of a well defined exponential disk probably implies that if a merger did occur it must have been between a gas-rich dwarf and a spiral, not between two equal mass spirals. The stellar spiral arms of NGC 4826 are trailing over part of the disk and leading in the outer disk. Recent numerical calculations by Byrd et al. for NGC 4622 suggest that long lasting leading arms could be formed by a close retrograde passage of a small companion. In this scenario, the outer counter-rotating gas disk in NGC 4826 might be the tidally stripped gas from the dwarf. However, in NGC 4826 the outer arms are leading, while it appears that in NGC 4622 the inner arms are leading. A realistic N-body/hydro simulation of a dwarf-spiral encounter is clearly needed. It may also be possible that the counter-rotating outer gas disk is due to gradual infall of gas from the halo, rather than from a discrete merger event.”
History of Observation:
M64 was discovered by Edward Pigott on March 23, 1779, just 12 days before Johann Elert Bode found it independently on April 4, 1779. Roughly a year later, Charles Messier independently rediscovered it on March 1, 1780 and cataloged it as M64. Said Pigot:
“.. on the 23rd of March [1779], I discovered a nebula in the constellation of Coma Berenices, hitherto, I presume, unnoticed; at least not mentioned in M. de la Lande’s Astronomy, nor in M. Messier’s ample Catalogue of nebulous Stars [of 1771]. I have observed it in an acromatic instrument, three feet long, and deduced its mean R.A. by comparing it to the following stars Mean R.A. of the nebula for April 20, 1779, of 191d 28′ 38″. Its light being exceedingly weak, I could not see it in the two-feet telescope of our quadrant, so was obliged to determine its declination likewise by the transit instrument. The determination, however, I believe, may be depended upon to two minutes: hence, the declination north is 22d 53″1/4. The diameter of this nebula I judged to be about two minutes of a degree.”
However, Pigott’s discovery got published only when read before the Royal Society in London on January 11, 1781, while Bode’s was published during 1779 and Messier’s in late summer, 1780. Pigott’s discovery was more or less ignored and recovered only by Bryn Jones in April 2002! (May the good Mr. Pigot know that he was remembered here and his reports placed first!!)
Messier 64, the Black Eye Galaxy. Credit: Miodrag Sekulic
So how did it get the name “Black Eye Galaxy”? We have Sir William Herschel to thank for that: “A very remarkable object, much elongated, about 12′ long, 4′ or 5′ broad, contains one lucid spot like a star with a small black arch under it, so that it gives one the idea of what is called a black eye, arising from fighting.” Of course, John Herschel perpetuated it when he wrote in his own notes:
“The dark semi-elliptic vacancy (indicated by an unshaded or bright portion in the figure,) which partially surrounds the condensed and bright nucleus of this nebula, is of course unnoticed by Messier. It was however seen by my Father, and shown by him to the late Sir Charles Blagden, who likened it to the appearance of a black eye, an odd, but not inapt comparison. The nucleus is somewhat elongated, and I have a strong suspicion that it may be a close double star, or extremely condensed double nebula.”
Locating Messier 64:
Locating M64 isn’t particularly easy. Begin by identifying bright orange Arcturus and the Coma Berenices star cluster (Melotte 111) about a hand span to the general west. As you relax and let your eyes dark adapt, you will see the three stars that comprise the constellation of Coma Berenices, but if you live under light polluted skies, you may need binoculars to find its faint stars. Once you have confirmed Alpha Comae, star hop approximately 4 degrees north/northwest to 35 Comae. You will find M64 around a degree to the northeast of star 35.
While Messier 64 is binocular possible, it will require very dark skies for average binoculars and will only show as a very small, oval contrast change. However, in telescopes as small as 102mm, its distinctive markings can be seen on dark nights with good clarity. Don’t fight over it… There’s plenty of dark dustlane in this Sleeping Beauty to go around!
The location of Messier 64 in the Coma Berenices constellation. Credit: IAU/Sky & Telescope magazine (Roger Sinnott & Rick Fienberg)
And here are the quick facts on this Messier Object to help you get started:
Object Name: Messier 64 Alternative Designations: M64, NGC 4826, The Black Eye Galaxy, Sleeping Beauty Galaxy, Evil Eye Galaxy Object Type: Type Sb Spiral Galaxy Constellation: Coma Berenices Right Ascension: 12 : 56.7 (h:m) Declination: +21 : 41 (deg:m) Distance: 19000 (kly) Visual Brightness: 8.5 (mag) Apparent Dimension: 9.3×5.4 (arc min)
The Sunflower Galaxy, a spiral galaxy located in the northern constellation Canes Venatici, as imaged by the NASA/ESA Hubble Space Telescope. Credits: ESA/Hubble & NASA
Welcome back to Messier Monday! Today, we continue in our tribute to our dear friend, Tammy Plotner, by looking at the “Sunflower Galaxy”, otherwise known as Messier 63.
In the 18th century, while searching the night sky for comets, French astronomer Charles Messier kept noting the presence of fixed, diffuse objects he initially mistook for comets. In time, he would come to compile a list of approximately 100 of these objects, hoping to prevent other astronomers from making the same mistake. This list – known as the Messier Catalog – would go on to become one of the most influential catalogs of Deep Sky Objects.
One of these objects is the spiral galaxy known as Messier 63 – aka. the Sunflower Galaxy. Located in the Canes Venatici constellation, this galaxy is located roughly 37 million light-years from Earth and has an active nucleus. Messier 63 is part of the M51 Group, a group of galaxies that also includes Messier 51 (the ‘Whirlpool Galaxy’), and can be easily spotted using binoculars and small telescopes.
Description:
Messier 63 is what is known as a a flocculent spiral galaxy, consisting of a central disc surrounded by many short spiral arm segments – one not connected by a central bar structure. Drifting along in space some 37,000 light years from our own galaxy, we known it interacts gravitationally with M51 (the Whirlpool Galaxy) and we also know that its outer regions are rotating so quickly that if it weren’t for dark matter – it would rip itself apart.
Infrared image of the Sunflower Galaxy (Messier 63) taken by the Spitzer Space Telescope. Credit: NASA/JPL-Caltech/SINGS Team
As Michele D. Thornley and Lee G. Mundy, of the Maryland University Department of Astronomy, indicated in a 1997 study:
“The morphology and inematics described by VLA observations of H I emission and FCRAO and Berkeley-Illinois-Maryland Association (BIMA) Array observations of CO emission provide evidence for the presence of low-amplitude density waves in NGC 5055. The distribution of CO and H I emission suggests enhanced gas surface densities along the NIR spiral arms, and structures similar to the giant molecular associations found in the grand design spirals M51 and M100 are detected. An analysis of H I and H? velocity fields shows the kinematic signature of streaming motions similar in magnitude to those of M100 in both tracers. The lesser degree of organization along the spiral arms of NGC 5055 may be due to the lower overall gas surface density, which in the arms of NGC 5055 is a factor of 2 lower than in M100 and a factor of 6 lower than in M51; an analysis of gravitational instability shows the gas in the arms is only marginally unstable and the interarm gas is marginally stable. The limited extent of the spiral arm pattern is consistent with an isolated density wave with a relatively high pattern speed.”
There very well could be a massive object hidden within. As Sebastien Blais-Ouellette of the Universite de Montreal said in a 1998 study:
“In a global kinematical study of NGC 5055 using high resolution Fabry-Perot, intriguing spectral line profiles have been observed in the center of the galaxy. These profiles seem to indicate a rapidly rotating disk with a radius near 365 pc and tilted 50 deg with respect to the major axis of the galaxy. In the hypothesis of a massive dark object, a naive keplerian estimate gives a mass around 10^7.2 to 10^7.5 M.”
Infrared image of the M63 galaxy made by Médéric Boquien, using data retrieved on the SINGS project public archives of the Spitzer Space Telescope. Credit: NASA/JPL-Caltech
But that’s not all they’ve found either… How about a lopsided, chemically unbalanced nucleus! As V.L. Afanasiev (et al) pointed out in their 2002 study:
“We have found a resolved chemically distinct core in NGC 5055, with the magnesium-enhanced region shifted by 2″.5 (100 pc) to the south-west from a photometric center, toward a kinematically identified circumnuclear stellar disk. Mean ages of stellar populations in the true nucleus, defined as the photometric center, and in the magnesium-enhanced substructure are coincident and equal to 3-4 Gyr being younger by several Gyr with respect to the bulge stellar population.”
Yep. It might be beautiful, but it’s warped. As G. Battaglia of the Kapteyn Astronomical Institute indicated in a 2005 study:
“NGC 5055 shows remarkable overall regularity and symmetry. A mild lopsidedness is noticeable, however, both in the distribution and kinematics of the gas. The tilted ring analysis of the velocity field led us to adopt different values for the kinematical centre and for the systemic velocity for the inner and the outer parts of the system. This has produced a remarkable result: the kinematical and geometrical asymmetries disappear, both at the same time. These results point at two different dynamical regimes: an inner region dominated by the stellar disk and an outer one, dominated by a dark matter halo offset with respect to the disk.”
Sunflower Galaxy (Messier 63). Credit: Adam Block/Mount Lemmon SkyCenter/University of Arizona
History of Observation:
Messier Object 63 was the very first discovery by Charles Messier’s friend and assistant Pierre Mechain, who turned it up on June 14, 1779. While Mechain himself did not write the notes, Messier did:
“Nebula discovered by M. Mechain in Canes Venatici. M. Messier searched for it; it is faint, it has nearly the same light as the nebula reported under no. 59: it contains no star, and the slightest illumination of the micrometer wires makes it disappear: it is close to a star of 8th magnitude, which precedes the nebula on the hour wire. M. Messier has reported its position on the Chart of the path of the Comet of 1779.”
Messier 63 would go on to be observed and resolved by Sir William Herschel and cataloged by his son John. It would be descriptively narrated by Admiral Symth and exclaimed over by many astronomers – one of the best of which was Lord Rosse: “Spiral? Darkness south flowing nucleus.” Of all the descriptions, perhaps the best belongs to Curtis, who first photographed it with the Crossley Reflector at Lick Observatory: “Has an almost stellar nucleus. The whorls are narrow, very compactly arranged, and show numerous almost stellar condensations.”
Locating Messier 63:
The beautiful Sunflower Galaxy is among one of the easiest of the Messier objects to find. It’s located almost precisely between Cor Caroli (Alpha Canes Venetici) and Eta Ursa Majoris. With the slightest of optical aid, stars 19, 20 and 23 CnV will show easily in finderscope or binoculars and M63 will be positioned right around two degrees away towards Eta UM.
The location of Messier 63 in the Canes Venatici constellation. Credit: IAU/Sky & Telescope magazine (Roger Sinnott & Rick Fienberg)
While this spiral galaxy has a nice overall brightness, it’s going to be very faint for binoculars, only showing as the tiniest contrast change in smaller models. However, even a modest telescope will easily see a faint oval shape with a concentrated nucleus. The more aperture you apply, the more details you will see. As size approaches 8″ and larger, expect to see spiral structure!
Power up… And look for the spiral in the Sunflower!
Object Name: Messier 63 Alternative Designations: M63, NGC 5055, Sunflower Galaxy Object Type: Type Sb Spiral Galaxy Constellation: Canes Venatici Right Ascension: 13 : 15.8 (h:m) Declination: +42 : 02 (deg:m) Distance: 37000 (kly) Visual Brightness: 8.6 (mag) Apparent Dimension: 10×6 (arc min)
The Messier 61 galaxy, as imaged by the Hubble Space Telescope. Credits: ESA/Hubble & NASA/G. Chapdelaine, L. Limatola and R. Gendler
Welcome back to Messier Monday! Today, we continue in our tribute to our dear friend, Tammy Plotner, by looking at the barred spiral galaxy known as Messier 61.
In the 18th century, while searching the night sky for comets, French astronomer Charles Messier kept noting the presence of fixed, diffuse objects he initially mistook for comets. In time, he would come to compile a list of approximately 100 of these objects, hoping to prevent other astronomers from making the same mistake. This list – known as the Messier Catalog – would go on to become one of the most influential catalogs of Deep Sky Objects.
One of these objects is the intermediate barred spiral galaxy known as Messier 61. As one of the larger galaxies located in the Virgo Cluster, this galaxy is roughly 52.5 million light years from Earth and contains some spectacular supernovae. It also has an Active Galactic Nucleus (AGN), meaning it has a Supermassive Black Hole (SMBH) at its center, and shows evidence of considerable star formation.
What You Are Looking At:
Spanning about 100,000 light years across and about the same size as our own Milky Way Galaxy, this grand old spiral is one of the largest in the Virgo Cluster… and one of the most active in terms of starbursts and supernovae. According to Luis Colina (et al) indicated in a 1997 study:
“A high-resolution Hubble Space Telescope WFPC2 F218W UV image of the barred spiral NGC 4303 (classified as a LINER-type active galactic nucleus [AGN]) reveals for the first time the existence of a nuclear spiral structure of massive star-forming regions all the way down to the UV-bright unresolved core of an active galaxy. The spiral structure, as traced by the UV-bright star-forming regions, has an outer radius of 225 pc and widens as the distance from the core increases. The UV luminosity of NGC 4303 is dominated by the massive star-forming regions, and the unresolved LINER-type core contributes only 16% of the integrated UV luminosity. The nature of the UV-bright LINER-type core—stellar cluster or pure AGN—is still unknown.”
The Virgo Cluster Galaxies. Credit & Copyright: Rogelio Bernal Andreo
Another fascinating aspect is Colina’s team has also identified a Super Star Cluster (SSC) withing Messier 61 as well. As Colina indicated in a 2002 study:
“These new HST/STIS results unambiguously show the presence of a compact SSC in the nucleus of a low-luminosity AGN, which is also its dominant ionizing source. We hypothesize that at least some LLAGNs in spirals could be understood as the result of the combined ionizing radiation emitted by an evolving SSC (i.e., determined by the mass and age) and a black hole accreting with low radiative efficiency (i.e., radiating at low sub-Eddington luminosities) coexisting in the inner few parsecs region. Complementary multifrequency studies give the first hints of the very complex structure of the central 10 pc of NGC 4303, where a young SSC apparently coexists with a low-efficiency accreting black hole and with an intermediate/old compact star cluster and where, in addition, an evolved starburst could also be present. If structures such as those detected in NGC 4303 are common in the nuclei of spirals, the modeling of the different stellar components and their contribution to the dynamical mass has to be established accurately before deriving any firm conclusion about the mass of central black holes of few to several million solar masses.”
Of course, studies don’t just stop there. As D. Tschoke (et al) indicated in a 2000 study:
“The late-type galaxy NGC 4303 (M61) is one of the most intensively studied barred galaxies in the Virgo Cluster. Its prominent enhanced star formation throughout large areas of the disk can be nicely studied due to its low inclination of about 27 degr. We present observations of NGC 4303 with the ROSAT PSPC and HRI in the soft X-ray (0.1-2.4 keV). The bulk of the X-ray emission is located at the nuclear region. It contributes more than 80% to the total observed soft X-ray flux. The extension of the central X-ray source and the L_X/L_Halpha ratio point to a low luminous AGN (LINER) with a circumnuclear star-forming region. Several separate disk sources can be distinguished with the HRI, coinciding spatially with some of the most luminous HII regions outside the nucleus of NGC 4303. The total star formation rate amounts to 1-2 Msun/yr. The X-ray structure follows the distribution of star formation with enhancement at the bar-typical patterns. The best spectral fit consists of a power-law component (AGN and HMXBs) and a thermal plasma component of hot gas from supernova remnants and superbubbles. The total 0.1-2.4 keV luminosity of NGC 4303 amounts to 5×10^40 erg/s, consistent with comparable galaxies, like e.g. NGC 4569.”
Hubble picture is the sharpest ever image of the core of spiral galaxy Messier 61. Taken using the High Resolution Channel of Hubble’s Advanced Camera for Surveys. Credit: ESA/NASA/HST
When it comes right down to it, it’s all about that star-forming ring. Said Eva Schinnerer (eta al) in a 2002 study:
“The UV continuum traces a complete ring that is heavily extincted north of the nucleus. Such a ring forms in hydrodynamic models of double bars, but the models cannot account for the UV emission observed on the leading side of the inner bar. Comparison with other starburst ring galaxies where the molecular gas emission and the star-forming clusters form a ring or tightly wound spiral structure suggests that the starburst ring in NGC 4303 is in an early stage of formation.”
How will today’s technologies continue to study the magnificent M61? Just take a look at what MOS can do! The very efficient multi-object-slit observing technique with the multi-mode instrument FORS1 has been demonstrated on the Virgo cluster galaxy NGC 4303 . Nineteen moveable slits at the instrument focal plane are positioned so that the faint light from several H II regions in this galaxy can pass into the spectrograph, while the much stronger “background” light (from the nearby areas in the galaxy and, to a large extent, from the Earth”s upper atmosphere) is blocked by the mask.
History of Observation:
M61 was discovered by Barnabus Oriani on May 5, 1779 when following the comet of that year. Said he, “Very pale and looking exactly like the comet.” As for our hero, Messier, he had also seen it on the same night – but thought it was the comet! Because Charles Messier was a good astronomer, he returned nightly to observe movement and it only took him a few days to realize his mistake and to admit it in his own notes:
“May 11, 1779. 61. 12h 10m 44s (182d 41′ 05″) +5d 42′ 05″ – Nebula, very faint & difficult to perceive. M. Messier mistook this nebula for the Comet of 1779, on the 5th, 6th and 11th of May; on the 11th he recognized that this was not the Comet, but a nebula which was located on its path and in the same point of the sky.”
Supernova SN2008in in the spiral galaxy Messier 61. Credit: Hewholooks/ Wikipedia Commons
Sir William and Sir John Herschel would also later return to M61 to assign it their own catalog numbers, both resolving certain portions of this wonderful galaxy – but neither truly beginning to understand what they were seeing. That took Admiral Smyth, who recorded in his notes:
“A large pale-white nebula, between the Virgo’s shoulders. This is a well defined object, but so feeble as to excite surprise that Messier detected it with his 3 1/2 foot telescope in 1779. Under the best action of my instrument it blazes towards the middle; but in H. [John Herschel]’s reflector it is faintly seen to be bicentral [an illusion caused by the bar], the nuclei 90″ apart, and lying sp [south preceding, SW] and nf [north following, NE]. It is preceded by four telescopic stars, and followed by another. Differentiated with the following object [17 Virginis], from which it bears about south by west, and is within a degree’s distance. This object is an outlier of a vast mass of discrete but neighboring nebulae, the spherical forms of which are indicative of compression.”
Locating Messier 61:
Locating Messier 61 is the Virgo Galaxy fields is relatively easily because it is so large and bright compared to any others in the area. Begin your hunt by identifying Beta and Delta Virginis. Between this pair you will see finderscope or binocular visible stars 17 and 16 Virginis. You destination is between this pair of stars. While M61 is binocular possible, it would require astronomical binoculars of approximately 80mm aperture and dark skies – although with excellent sky conditions the nucleus can be glimpsed with apertures as small as 60mm.
This star chart for M61 represents the view from mid-northern latitudes for the given month and time. Credits: NASA/Stellarium
In a small aperture telescope, M61 will appear as a very faint oval with a bright central region. As size increases, so do details and resolution. At 6-8″ in size, the nucleus becomes very clear and beginnings of spiral arms start to resolve. In the 10-12″ range, spiral structure becomes clear and some mottling texture becomes clear.
Enjoy your observations!
And here are the quick facts on Messier 61 to help you get started:
Object Name: Messier 61
Alternative Designations: M61, NGC 4303
Object Type: Type SABbc Spiral Galaxy
Constellation: Virgo
Right Ascension: 12 : 21.9 (h:m)
Declination: +04 : 28 (deg:m)
Distance: 60000 (kly)
Visual Brightness: 9.7 (mag)
Apparent Dimension: 6×5.5 (arc min)
Messier 60, Messier 59 and Messier 58. Credit: Wikisky
Welcome back to Messier Monday! Today, we continue in our tribute to our dear friend, Tammy Plotner, by looking at the spiral galaxy known as Messier 59.
In the 18th century, while searching the night sky for comets, French astronomer Charles Messier kept noting the presence of fixed, diffuse objects he initially mistook for comets. In time, he would come to compile a list of approximately 100 of these objects, hoping to prevent other astronomers from making the same mistake. This list – known as the Messier Catalog – would go on to become one of the most influential catalogs of Deep Sky Objects.
One of these objects is the elliptical galaxy known as Messier 59 (aka. NGC 4621). This galaxy is located approximately 60 million light-years from Earth in the direction of the southern Virgo constellation. Sitting just a few degrees away Messier 60, and bordered at a distance by Messier 58, this galaxy is visible using smaller instruments, but is best observed using a larger telescope.
Atlas image of Messier 59 obtained by the Two micron All Sky Survey (2MASS). Credit: 2MASS/NASA/UMass
Description:
Located about 60 million light years away and spanning about 90 million light years of space, but what exactly is its type? Says Takao Mizuno (et al) in their 1996 study:
“We decomposed two-dimensionally an elliptical galaxy, NGC 4621, which shows deviations from the brightness distribution law. We have found that its brightness distribution can be reproduced by three components possessing constant ellipticities of the residuals in the circular region of radius. The component obeying the aw has 62% of the total light, and, hence, is the main body of this elliptical galaxy.” So it might not be the biggest or the brightest of the group, but it is home to nearly 2000 globular clusters. This isn’t news when it comes to this galaxy type, but what is news is how they rotate… the wrong way!
“We present adaptive optics assisted OASIS integral field spectrography of the S0 galaxy NGC 4621. Two-dimensional stellar kinematical maps (mean velocity and dispersion) reveal the presence of a 60 pc diameter counter-rotating core (CRC), the smallest observed to date.” says Fabien Wernli (et al), “The OASIS data also suggests that the kinematic center of the CRC is slightly offset from the center of the outer isophotes. This seems to be confirmed by archival HST/STIS data. We also present the HST/WFPC2 V-I colour map, which exhibits a central elongated red structure, also slightly off-centered in the same direction as the kinematic centre. Although the stellar velocities are reasonably fitted, including the region of the counter-rotating core, significant discrepancies between the model and the observations demonstrate the need for a more general model.”
What could account for such unusual behavior? Try a quiet black hole! As J. M. Wrobel (et al) indicated in their 2008 study:
“The nearby elliptical galaxies NGC 4621 and NGC 4697 each host a supermassive black hole. Analysis of archival Chandra data and new NRAO Very Large Array data shows that each galaxy contains a low-luminosity active galactic nucleus (LLAGN), identified as a faint, hard X-ray source that is astrometrically coincident with a faint 8.5-GHz source. The black holes energizing these LLAGNs have Eddington ratios placing them in the so-called quiescent regime. The emission from these quiescent black holes is radio-loud, suggesting the presence of a radio outflow. Also, application of the radio-X-ray-mass relation from Yuan & Cui for quiescent black holes predicts the observed radio luminosities to within a factor of a few. Significantly, that relation invokes X-ray emission from the outflow rather than from an accretion flow. The faint, but detectable, emission from these two massive black holes is therefore consistent with being outflow-dominated.”
The M59 spiral galaxy. Credit: NOAO
History of Observation:
Both M59 and neighboring M60 were discovered on April 11, 1779 by Johann Gottfried Koehler who wrote: “Two very small nebulae, hardly visible in a 3-foot telescope: The one above the other.” Charles Messier would independently recover it four days later and state in his notes:
“Nebula in Virgo and in the neighborhood of the preceding [M58], on the parallel of epsilon [Virginis], which has served for its [position] determination: it is of the same light as the above, equally faint. M. Messier reported it on the Chart of the Comet of 1779.”
While both William and John Herschel would also observe it, it sometimes confounds me that they didn’t seem to notice all the other galaxies around it! Fortunately for historic record, Admiral Smyth did:
“A fine field is exhibited under the eye-piece, which magnifies 93 times, just as this object [M60 with NGC 4647] enters, because the bright little nebula 59 M. is quitting the np [north preceding, NW] verge, and another small one is seen in the upper part, H. 1402 [NGC 4638]: in fact, four nebulae at once.”
Locating Messier 58:
M59 is a telescope-only object and requires patience to find. Because the Virgo Galaxy field contains so many galaxies which can easily be misidentified, it is sometimes easier to “hop” from one galaxy to the next. In this case, we need to start by locating bright Vindemiatrix (Epsilon Virginis) almost due east of Denebola. Then starhop four and a half degrees west and a shade north of Epsilon to locate one of the largest elliptical galaxies presently known – M60.
The location of M59, which sits between M58 and M60 in the direction of the Virgo constellation. Credit: IAU
At a little brighter than magnitude 9, this galaxy could be spotted with binoculars, but stick with your telescope. In the same low power field (depending on aperture size) you may also note faint NGC 4647 which only appears to be interacting with M60. Also in the field to the west (the direction of drift) is the Messier we’re looking for, bright cored elliptical galaxy M59.
In a smaller telescope, do not expect to see much. What will appear at low power is a tiny egg-shaped patch of contrast change with a brighter center. As aperture increases, a sharper nucleus will begin to appear as you move into the 4-6″ size range at dark sky locations, but elliptical galaxies do not show details. As with all galaxies, dark skies are a must!
Enjoy your journey around the Virgo Galaxy Field!
Object Name: Messier 59 Alternative Designations: M59, NGC 4621 Object Type: E5 Galaxy Constellation: Virgo Right Ascension: 12 : 42.0 (h:m) Declination: +11 : 39 (deg:m) Distance: 60000 (kly) Visual Brightness: 9.6 (mag) Apparent Dimension: 5×3.5 (arc min)
The galaxies of Messier 58, Messier 59, Messier 60, Messier 87, Messier 89 and Messier 90. Credit: Wikisky
Welcome back to Messier Monday! Today, we continue in our tribute to our dear friend, Tammy Plotner, by looking at the barred spiral galaxy, Messier 58.
In the 18th century, while searching the night sky for comets, French astronomer Charles Messier kept noting the presence of fixed, diffuse objects in the night sky. In time, he would come to compile a list of approximately 100 of these objects, with the purpose of making sure that astronomers did not mistake them for comets. However, this list – known as the Messier Catalog – would go on to serve a more important function, becoming one of the first catalogs of Deep Sky Objects.
One of these objects is the intermediate barred spiral galaxy known as Messier 58, which is located approximately 68 million light years away in the Virgo constellation. In addition to being one of just four barred spiral galaxies in the Messier Catalog, it is also one of the brightest galaxies in the Virgo Supercluster. Due to its proximity in the sky to other objects in the Virgo Galaxy Field, it can be seen only with the help of a telescope or a pair of large binoculars.
Description:
This beautiful old barred spiral galaxy located approximately 68 million light-years from Earth. Although it might appear pretty plain, it has some great things going for it… namely an active galactic nucleus. As Marcella Contini indicated in a 2004 study:
“We have modelled the low-luminosity active galactic nuclei (AGN) NGC 4579 by explaining both the continuum and the line spectra observed with different apertures. It was found that the nuclear emission is dominated by an AGN such that the flux from the active centre (AC) is relatively low compared with that of the narrow emission-line region (NLR) of Seyfert galaxies. However, the contribution of a young starburst cannot be neglected, as well as that of shock-dominated clouds with velocities of 100, 300 and 500kms-1. A small contribution from an older starburst with an age of 4.5 Myr, probably located in the external nuclear region, is also found. HII regions appear in the extended regions, where radiation and shock-dominated clouds prevail.
“The continuum SED of NGC 4579 is characterized by the strong flux from an old stellar population. Emissions in the radio range show synchrotron radiation from the base of the jet outflowing from the accretion disc within 0.1 pc from the active centre. Radio emission within intermediate distances is explained by the bremsstrahlung from gas downstream of low-velocity shocks reached by a relatively low radiation flux from the AC. In extended regions the radio emission is synchrotron radiation created by the Fermi mechanism at the shock front. The shocks are created by collision of clouds with the jet. All types of emissions observed at different radius from the centre can be reconciled with the presence of the jet.”
The Messier 58 barred spiral galaxy. Credit: Adam Block/Mount Lemmon SkyCenter/University of Arizona
Yet where is this gas traveling to and why? According to 2014 study by S. Garcia-Burillo (et al):
“We created a complete gravity torque map of the disk of the LINER/Seyfert 1.9 galaxy NGC 4579. We quantify the efficiency of angular momentum transport and search for signatures of secular evolution in the fueling process from r ~ 15 kpc down to the inner r ~ 50 pc around the active galactic nucleus (AGN). The derived gravity torque budget in NGC 4579 shows that inward gas flow is occurring on different spatial scales in the disk. In the outer disk, the decoupling of the spiral allows the gas to efficiently populate the UHR region, and thus produce net gas inflow on intermediate scales. The co rotation barrier seems to be overcome by secular evolution processes. The gas in the inner disk is efficiently funneled by gravity torques down to r ~ 300 pc. Closer to the AGN, gas feels negative torques due to the combined action of the large-scale bar and the inner oval. The two m=2 modes act in concert to produce net gas inflow down to r ~ 50 pc, providing clear smoking gun evidence of inward gas transport on short dynamical timescales.”
What causes inward transport of gases? Why, a massive gravity pull of course. And what could be more gravitational attractive than a black hole! As Eliot Quataert (et al) indicated in their 1999 study:
“M81 and NGC 4579 are two of the few low-luminosity active galactic nuclei which have an estimated mass for the central black hole, detected hard X-ray emission, and detected optical/UV emission. In contrast to the canonical “big blue bump,” both have optical/UV spectra which decrease with increasing frequency in a plot. Barring significant reddening by dust and/or large errors in the black hole mass estimates, the optical/UV spectra of these systems require that the inner edge of a geometrically thin, optically thick, accretion disk lies at roughly 100 Schwarzschild radii. The observed X-ray radiation can be explained by an optically thin, two temperature, advection-dominated accretion flow at smaller radii.”
Galaxy NGC 4579 was captured by the Spitzer Infrared Nearby Galaxy Survey (SINGS) Legacy Project using the Spitzer Space Telescope’s Infrared Array Camera (IRAC). In this image, the red structures are areas where gas and dust are thought to be forming new stars, while the blue light comes from mature stars. This SINGS image is a four-channel, false-color composite, where blue indicates emission at 3.6 microns, green corresponds to 4.5 microns, and red to 5.8 and 8.0 microns. The contribution from starlight (measured at 3.6 microns) in this picture has been subtracted from the 5.8 and 8 micron images to enhance the visibility of the dust features.
Messier 58 (NGC 4579), as imaged by the Spitzer Infrared Nearby Galaxy Survey (SINGS) Legacy Project using the Spitzer Space Telescope’s Infrared Array Camera (IRAC). Credit: NASA/JPL-Caltech/R. Kennicutt (University of Arizona) and the SINGS Team
History of Observation:
When Charles Messier discovered this one on April 15, 1779, I’m sure he didn’t know he was looking back into time when he wrote:
“Very faint nebula discovered in Virgo, almost on the same parallel as Epsilon, 3rd mag. The slightest light for illuminating the micrometer wires makes it disappear. M. Messier reported it on the chart of the Comet of 1779, which is located in the volume of the Academy for the same year.”
Messier 58 may not have been a comet, but it certainly was another distant cousin of our own Milky Way!
Locating Messier 58:
Finding M58 requires a telescope or large binoculars, and lots of patience. Because the Virgo Galaxy field contains so many galaxies which can easily be misidentified, it is sometimes easier to “hop” from one galaxy to the next! In this case, we need to start by locating bright Vindemiatrix (Epsilon Virginis) almost due east of Denebola. Let’s hop four and a half degrees west and a shade north of Epsilon to locate one of the largest elliptical galaxies presently known – M60.
At a little brighter than magnitude 9, this galaxy could be spotted with binoculars, but stick with your telescope. In the same low power field (depending on aperture size) you may also note faint NGC 4647 which only appears to be interacting with M60. Also in the field to the west (the direction of drift) is our next Messier, bright cored elliptical M59. Now we will need to continue about an average eyepiece field of view, or a degree further west of this group to bring you to our “galactic twin”, fainter M58.
The location of M58, in the direction of the Virgo constellation. Credit: IAU
In a smaller telescope, do not expect to see much. What will appear at low power is a tiny egg-shaped patch of contrast change. As aperture increases, so does detail and a bright nucleus will begin to appear as you move into the 4-6″ size range and dark sky locations. As with all galaxies, dark skies are a must!
And here are the quick facts on this object to help you get started:
Object Name: Messier 58 Alternative Designations: M58, NGC 4579 Object Type: SBc Galaxy Constellation: Virgo Right Ascension: 12 : 37.7 (h:m) Declination: +11 : 49 (deg:m) Distance: 60000 (kly) Visual Brightness: 9.7 (mag) Apparent Dimension: 5.5×4.5 (arc min)
Hubble image of the Ring Nebula (aka. Messier 57). Credit: NASA/ESA/ Hubble Heritage (STScI/AURA) – ESA /Hubble Collaboration
Welcome back to Messier Monday! We continue our tribute to our dear friend, Tammy Plotner, by looking at the the Big Ring itself, the planetary nebula known as Messier 57. Enjoy!
In the 18th century, while searching the night sky for comets, French astronomer Charles Messier kept noting the presence of fixed, diffuse objects in the night sky. In time, he would come to compile a list of approximately 100 of these objects, with the purpose of making sure that astronomers did not mistake them for comets. However, this list – known as the Messier Catalog – would go on to serve a more important function.
One of these objects is known as Messier 57, a planetary nebula that is also known as the Ring Nebula. This object is located about 2,300 light years from Earth in the direction of the Lyra constellation. Because of its proximity to Vega, the brightest star in Lyra and one of the stars that form the Summer Triangle, the nebula is relatively easy to find using binoculars or a small telescope.
What You Are Looking At:
Here you see the remainders of a sun-like star… At one time in its life, it may have had twice the mass of Sol, but now all that’s left is a white dwarf that burns over 100,000 degrees kelvin. Surrounding it is an envelope about 2 to 3 light years in size of what once was its outer layers – blown away in a cylindrical shape some 6000 to 8000 years ago. Like looking down the barrel of a smoking gun, we’re looking back in time at the end of a Mira-like star’s evolutionary phase.
It’s called a planetary nebula, because once upon a time before telescopes could resolve them, they appeared almost planet-like. But, as for M57, the central star itself is no larger than a terrestrial planet! The tiny white dwarf star, although it could be as much as 2300 light years away, has an intrinsic brightness of about 50 to 100 times that of our Sun.
One of the most beautiful features of M57 is the structure in the ring itself, sometimes called braiding – but scientifically known as “knots” in the gaseous structure. As C.R. O’Dell (et al) indicated in their 2003 study:
“We have studied the closest bright planetary nebulae with the Hubble Space Telescope’s WFPC2 in order to characterize the dense knots already known to exist in NGC 7293. We find knots in all of the objects, arguing that knots are common, simply not always observed because of distance. The knots appear to form early in the life cycle of the nebula, probably being formed by an instability mechanism operating at the nebula’s ionization front. As the front passes through the knots they are exposed to the photoionizing radiation field of the central star, causing them to be modified in their appearance. This would then explain as evolution the difference of appearance like the lacy filaments seen only in extinction in IC 4406 on the one extreme and the highly symmetric “cometary” knots seen in NGC 7293. The intermediate form knots seen in NGC 2392, NGC 6720, and NGC 6853 would then represent intermediate phases of this evolution.”
However, examining things like planetaries nebulae in different wavelengths of light can tell us so much more about them. Behold the beauty when see through the Spitzer Space Telescope! As M.M. Roth explained in a 2007 study:
“Emission nebulae like H II regions, Planetary Nebulae, Novae, Herbig Haro objects etc. are found as extended objects in the Milky Way, but also as point sources in other galaxies, where they are sometimes observable out to very large distances due to the high contrast provided by some prominent emission lines. It is shown how 3D spectroscopy can be used as a powerful tool for observations of both large resolved emission nebulae and distant extragalactic objects, with special emphasis on faint detection limits.”
History of Observation:
This deep space object was first discovered in early January 1779 by Antoine Darquier who wrote in his notes:
“This nebula, to my knowledge, has not yet been noticed by any astronomer. One can only see it with a very good telescope, it is not resembling any of those [nebula] already known; it has the apparent dimension of Jupiter, is perfectly round and sharply limited; its dull glow resembles the dark part of the Moon before the first and after the last quarter. Meanwhile, the center appears a bit less pale than the remaining part of its surface.”
Although Darquier did not post a date, it is believed his observation preceded Messier’s independent recovery made on January 31, 1779 when he states that Darquier picked it up before him:
“A cluster of light between Gamma and Beta Lyrae, discovered when looking for the Comet of 1779, which has passed it very close: it seems that this patch of light, which is round, must be composed of very small stars: with the best telescopes it is impossible to distinguish them; there stays only a suspicion that they are there. M. Messier reported this patch of light on the Chart of the Comet of 1779. M. Darquier, at Toulouse, discovered it when observing the same comet, and he reports: ‘Nebula between gamma and beta Lyrae; it is very dull, but perfectly outlined; it is as large as Jupiter and resembles a planet which is fading’.”
A few years later, Sir William Herschel would also observe Messier Object 57 with his superior telescope and in his private notes he writes:
“Among the curiosities of the heavens should be placed a nebula, that has a regular, concentric, dark spot in the middle, and is probably a Ring of stars. It is of an oval shape, the shorter axis being to the longer as about 83 to 100; so that, if the stars form a circle, its inclination to a line drawn from the sun to the center of this nebula must be about 56 degrees. The light is of the resolvable kind [i.e., mottled], and in the northern side three very faint stars may be seen, as also one or two in the southern part. The vertices of the longer axis seem less bright and not so well defined as the rest. There are several small stars very bear, but none seems to belong to it.”
Admiral Smyth would go on in later years to add his own detailed observations to history’s records:
“This annular nebula, between Beta and Gamma on the cross-piece of the Lyre, forms the apex of a triangle which it makes with two stars of the 9th magnitude; and its form is that of an elliptic ring, the major axis of which trends sp to nf [SW to NE]. This wonderful object seems to have been noted by Darquier, in 1779; but neither he nor his contemporaries, Messier and Méchain, discerned its real form, seeing in this aureola of glory only “a mass of light in the form of a planetary disc, very dingy in colour.”
“Sir W. Herschel called it a perforated resolvable nebula, and justly ranked it among the curiosities of the heavens. He considered the vertices of the longer axis less bright and not so well defined as the rest; and he afterwards added: ‘By the observations of the 20-feet telescope, the profundity of the stars, of which it probably consists, must be of a higher than the 900th order, perhaps 950.'”
“This is a vast view of the ample and inconceivable dimensions of the spaces of the Universe; and if the oft-cited cannon-ball, flying with the uniform velocity of 500 miles an hour, would require millions of years to reach Sirius, what an incomprehensible time it would require to pass so overwhelming an interval as 950 times the distance! And yet, could we arrive there, by all analogy, no boundary would meet the eye, but thousands and ten thousands of other remote and crowded systems would still bewilder the imagination.
“In my refractor this nebula has a most singular appearance, the central vacuity being black, so as to countenance the trite remark of its having a hole through it. Under favourable circumstances, when the instrument obeys the smooth motion of the equatorial clock, it offers the curious phenomenon of a solid ring of light in the profundity of space. The annexed sketch affords a notion of it. Sir John Herschel, however, with the superior light of his instrument, found that the interior is far from absolutely dark. “It is filled,’ he says, ‘with a feeble but very evident nebulous light, which I do not remember to have been noticed by former observers.'”
Since Sir John’s observation, the powerful telescope of Lord Rosse has been directed to this subject, and under powers 600, 800, and 1000, it displayed very evident symptoms of resolvability at its minor axis. The fainter nebulous matter which fills it, was found to be irregularly distributed, having several stripes or wisps in it, and the regularity of the outline was broken by appendages branching into space, of which prolongations the brightest was in the direction of the major axis.
Locating Messier 57:
M57 is a breeze to locate because it is positioned between Beta and Gamma Lyrae (the westernmost pair of the lyre’s stars), at about one-third the distance from Beta to Gamma. While it is easily seen in binoculars, it is a little difficult to identify because of its small size, so binoculars must be very steady to distinguish it from the surrounding star field.
In even a small telescope at minimum power, you’ll quickly notice a very small, but perfect ring structure which takes very well to magnification. Despite low visual brightness, M57 actually takes well to urban lighting conditions and can even be spied during fairly well moonlit nights. Larger aperture telescopes will easily see braiding in the nebula structure and often glimpse the central star. May you also see the many faces of the “Ring”!
The location of Messier 57 in the Lyra Constellation. Credit: IAU and Sky & Telescope magazine (Roger Sinnott & Rick Fienberg)
And here are the quick facts on Messier 57 to help you get started:
Object Name: Messier 57 Alternative Designations: M57, NGC 6720, the “Ring Nebula” Object Type: Planetary Nebula Constellation: Lyra Right Ascension: 18 : 53.6 (h:m) Declination: +33 : 02 (deg:m) Distance: 2.3 (kly) Visual Brightness: 8.8 (mag) Apparent Dimension: 1.4×1.0 (arc min)
