APOD: Portrait of NGC 1055 (2020 Dec 24)

[APOD Robot]

Portrait of NGC 1055

Explanation: Big, beautiful spiral galaxy NGC 1055 is a dominant member of a small galaxy group a mere 60 million light-years away toward the aquatically intimidating constellation Cetus. Seen edge-on, the island universe spans over 100,000 light-years, a little larger than our own Milky Way galaxy. The colorful, spiky stars decorating this cosmic portrait of NGC 1055 are in the foreground, well within the Milky Way. But the telltale pinkish star forming regions are scattered through winding dust lanes along the distant galaxy's thin disk. With a smattering of even more distant background galaxies, the deep image also reveals a boxy halo that extends far above and below the central bluge and disk of NGC 1055. The halo itself is laced with faint, narrow structures, and could represent the mixed and spread out debris from a satellite galaxy disrupted by the larger spiral some 10 billion years ago.

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[Ann]

NGC 1055. Photo: Martin Pugh.

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NGC 1055 and its famous neighbor M77. Photo: Dieter Willasch.

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NGC 1055. Many small blue star clusters and pink emission nebulas are visible, and the boxy halo is bright and prominent. Photo: Sorry, I don't know.

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M82, with tremendous outflows from the center because of raging star formation and large numbers of supernovas there. Photo: NASA/Hubble, https://www.nasa.gov/feature/goddard/2017/messier-82-the-cigar-galaxy.

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NGC 1055 is a large edge-on galaxy, presumably larger than the Milky Way. I find its halo quite interesting.

APOD Robot wrote:

With a smattering of even more distant background galaxies, the deep image also reveals a boxy halo that extends far above and below the central bluge and disk of NGC 1055. The halo itself is laced with faint, narrow structures, and could represent the mixed and spread out debris from a satellite galaxy disrupted by the larger spiral some 10 billion years ago.

There is of course a spelling mistake here - it should be "bulge" instead of "bluge". But as the caption said, the halo of NGC 1055 is boxy and laced with narrow structures. Don't ask me how anyone would know that these structures are debris from a collision that happened 10 billion years ago!

NGC 1055 is located close to well-known galaxy M77. Wikipedia wrote about NGC 1055 and M77:

Wikipedia wrote:

It is a binary system together with the bright spiral galaxy M77 (NGC 1068). These two are the largest galaxies of a small galaxy group that also includes NGC 1073, and five other small irregular galaxies.

The separation between M77 and NGC 1055 is considerably smaller than the separation between the Milky Way and Andromeda (which is about two million light-years):

Wikipedia wrote:
Based on the published red shift, (Hubble Constant of 62 km/s per Mpc) a rough distance estimate for NGC 1055 is 52 million light-years, with a diameter of about 115,800 light-years. The separation between NGC 1055 and M77 is about 442,000 light-years.

Wow. So if we are supposed to be heading for a giant smash-up with Andromeda, you have to wonder about the fireworks that will accompany the trainwreck of NGC 1055 and M77!

Wikipedia wrote:

NGC 1055 is a bright infrared and radio source, particularly in the wavelength for warm carbon monoxide. Astronomers believe that this results from unusually active star formation.

Interesting. There are no visual signs of any unusually active star formation in NGC 1055. The galaxy is rather red in color, although not remarkably so (not nearly as red as Andromeda!), and the visible star clusters and emission nebulas are relatively small.

Admittedly NGC 1055 is bright in the far infrared, about two magnitudes brighter in the far infrared than in B light, which is (often, but perhaps not absolutely always) a sign of star formation. We may compare NGC 1055 with (mostly red and almost dead) Andromeda, which is one magnitude fainter in far infrared light than in B light!

It could be, of course, that there is a huge amount of star formation in the center of NGC 1055, where we can't see it behind all the dust. And the boxy halo could be a a remnant of outflows from the center as a result of star formation there. But the halo of NGC 1055 is nothing compared with the halo of M82!

Now I'm off to celebrate Christmas, because it's Christmas Eve, which is the big day of Christmas here in Scandinavia!

Ann

[zeecatman]

Great post, Ann. On the subject of the starburst galaxy M82, from an inexpert and possibly naive point of view, I noticed the shape of its outflowing "wings" appear very similar to the hourglass-shape of the famous Orion Nebula. Is this shape significant or common in space? Does it have any implications for the body it belongs to? Either way, it's very aesthetically pleasing.

[Ann]

The Southern Crab Nebula, an hourglass-shaped nebula surrounding an old Mira-type variable, which is about to shed its other atmosphere and become a planetary nebula and a white dwarf. Photo: NASA, ESA, and STScI.

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The Hourglass Nebula in the Lagoon Nebula, surrounding a very young massive star that has recently been born.

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Yes, hourglass shapes are common in space.

Ann

[orin stepanek]

NGC 1055 is a very beautiful galaxy!

Ah! Pizza for Christmas Eve; Just needs beer!

[VictorBorun]

The separation between NGC 1055 and M77 is about 442,000 light-years.

Do I get it right: the disk galaxies in a binary system don't do a tidal lock. They pose like runaway disk saws about to saw each other in two.

And the pair of NGC 1055 and M77 looks like a pair of identical twins at that. It will be a fair crush test.

[Chris Peterson]

The separation between NGC 1055 and M77 is about 442,000 light-years.

Do I get it right: the disk galaxies in a binary system don't do a tidal lock. They pose like runaway disk saws about to saw each other in two.

Only rigid bodies can tidally lock.

[neufer]

The separation between NGC 1055 and M77 is about 442,000 light-years.

Do I get it right: the disk galaxies in a binary system don't do a tidal lock. They pose like runaway disk saws about to saw each other in two.

Only rigid bodies can tidally lock.

Wouldn't you say that our ocean tides are tidally locked to the Moon

[Chris Peterson]

Do I get it right: the disk galaxies in a binary system don't do a tidal lock. They pose like runaway disk saws about to saw each other in two.

Only rigid bodies can tidally lock.

Wouldn't you say that our ocean tides are tidally locked to the Moon :?:

I would not. Tides are not bodies or objects. They are patterns of movement in the ocean. Tidal forces certainly shape the movements of stars in a galaxy, just like they create currents in oceans. But a galaxy can no more be tidally locked to something than an ocean can.

[MarkBour]

Do I get it right: the disk galaxies in a binary system don't do a tidal lock. They pose like runaway disk saws about to saw each other in two.

Only rigid bodies can tidally lock.

Wouldn't you say that our ocean tides are tidally locked to the Moon

Ha! I suppose a tidal pool in Scotland, if it were large enough, could be called a tidal loch.

(Image: A tide pool near Cruden Bay.)

[neufer]

Only rigid bodies can tidally lock.

Wouldn't you say that our ocean tides are tidally locked to the Moon

Ha! I suppose a tidal pool in Scotland, if it were large enough, could be called a tidal loch.

Co‐tidal chart for Loch Ness from a numerical tidal model, indicating a small clockwise amphidromic system in the middle of the loch. Co‐tidal lines for Greenwich phase lag are shown every 60°, while co‐range lines are drawn every 0.15 mm.

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<<Loch Ness, located along the Great Glen fault, in the north of Scotland, is approximately 37 km long, has an average width of 1.6 km, and a maximum depth of 227 m. It aligns 38° east of north, approximately southwest to northeast, and at its northern end is connected to the tidal Moray Firth and North Sea, by a short (∼13 km) length of the River Ness. At 16 m above mean sea level, Loch Ness is not directly influenced by the ocean tide. However, we have been able to observe small (mm) tides in the Loch due to direct gravitational tidal attraction, and due to the loading of the solid earth by the ocean tides of the adjacent seas. This is believed to be the first observation in a European lake of an astronomical tide primarily due to loading.

Figure 5 presents typical model findings indicating a largely standing wave character, with M2 difference between the two ends consistent with expectations from the applied potential, and with a clockwise amphidromic system in the middle. This exercise confirmed that a comparison of measurements to direct gravitational and loading potentials as in Figure 3b is a valid one. Amplitudes and phases from this model were used to confirm that the self‐loading due to Loch Ness tides mentioned above is negligible.>>

[VictorBorun]

Only rigid bodies can tidally lock.

Are not the disk gas-rich galaxies rigid when:
1) alone and keeping themselves flat, smoothely whirling
2) run upon another body and conduct a mighty bing through their bodies

Is Earth rigid, is the Earth's ocean rigid? And are lito- and hydrospheres going to tidally lock with Moon and Sun?

Rigid enough though spherical enough too. Earth's future tidal lock with Sun is not out of the question.

[Chris Peterson]

Only rigid bodies can tidally lock.

Are not the disk gas-rich galaxies rigid when:
1) alone and keeping themselves flat, smoothely whirling
2) run upon another body and conduct a mighty bing through their bodies

Is Earth rigid, is the Earth's ocean rigid? And are lito- and hydrospheres going to tidally lock with Moon and Sun?

Rigid enough though spherical enough too. Earth's future tidal lock with Sun is not out of the question.

Galaxies are never rigid.

The Earth has a rigid lithosphere. Its ocean is not rigid and its interior is not rigid. Neither the oceans nor the interior (as long as it is fluid) could reasonably be seen as being able to be tidally locked to another body.

[neufer]

Only rigid bodies can tidally lock.

The Earth has a rigid lithosphere. Its ocean is not rigid and its interior is not rigid.

Neither the oceans nor the interior (as long as it is fluid) could reasonably be seen as being able to be tidally locked to another body.

Double star system Beta Lyrae by Chesley Bonestell

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Beta Lyrae resolved using the CHARA array

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<<Beta Lyrae officially named Sheliak (Arabic: الشلياق), the traditional name of the system, is a multiple star system in the constellation of Lyra. Based on parallax measurements obtained during the Hipparcos mission, it is approximately 960 light-years distant from the Sun.

The variable luminosity of this system was discovered in 1784 by the British amateur astronomer John Goodricke. The orbital plane of this system is nearly aligned with the line of sight from the Earth, so the two stars periodically eclipse each other. This causes Beta Lyrae to regularly change its apparent magnitude from +3.2 to +4.4 over an orbital period of 12.9414 days. It forms the prototype of a class of ellipsoidal "contact" eclipsing binaries.

The two components are so close together that they cannot be resolved with optical telescopes, forming a spectroscopic binary. In 2008, the primary star and the accretion disk of the secondary star were resolved and imaged using the CHARA Array interferometer and the Michigan InfraRed Combiner (MIRC) in the near infrared H band, allowing the orbital elements to be computed for the first time.

In addition to the regular eclipses, the system shows smaller and slower variations in brightness. These are thought to be caused by changes in the accretion disc and are accompanied by variation in the profile and strength of spectral lines, particularly the emission lines. The variations are not regular but have been characterised with a period of 282 days.

Beta Lyrae Aa is a semidetached binary system made up of a stellar class B6-8 primary star and a secondary that is probably also a B-type star. The fainter, less massive star in the system was once the more massive member of the pair, which caused it to evolve away from the main sequence first and become a giant star. Because the pair are in a close orbit, as this star expanded into a giant it filled its Roche lobe and transferred most of its mass over to its companion.

The secondary, now more massive star is surrounded by an accretion disk from this mass transfer, with bipolar, jet-like features projecting perpendicular to the disk. This accretion disk blocks humans' view of the secondary star, lowering its apparent luminosity and making it difficult for astronomers to pinpoint what its stellar type is. The amount of mass being transferred between the two stars is about 2 × 10⁻⁵ solar masses per year, or the equivalent of the Sun's mass every 50,000 years, which results in an increase in orbital period of about 19 seconds each year. The spectrum of Beta Lyrae shows emission lines produced by the accretion disc. The disc produces around 20% of the brightness of the system.

In 2006, an adaptive optics survey detected a possible third companion, Beta Lyrae Ab. It was detected at 0.54" angular separation with a differential magnitude of +4.53. The difference in magnitudes suggests its spectral class is in the range B2-B5 V. This companion would make Beta Lyrae A a hierarchical triple system.>>

[Chris Peterson]

Only rigid bodies can tidally lock.

The Earth has a rigid lithosphere. Its ocean is not rigid and its interior is not rigid.

Neither the oceans nor the interior (as long as it is fluid) could reasonably be seen as being able to be tidally locked to another body.

Double star system Beta Lyrae by Chesley Bonestell

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Beta Lyrae resolved using the CHARA array

---

<<Beta Lyrae officially named Sheliak (Arabic: الشلياق), the traditional name of the system, is a multiple star system in the constellation of Lyra. Based on parallax measurements obtained during the Hipparcos mission, it is approximately 960 light-years distant from the Sun.

The variable luminosity of this system was discovered in 1784 by the British amateur astronomer John Goodricke. The orbital plane of this system is nearly aligned with the line of sight from the Earth, so the two stars periodically eclipse each other. This causes Beta Lyrae to regularly change its apparent magnitude from +3.2 to +4.4 over an orbital period of 12.9414 days. It forms the prototype of a class of ellipsoidal "contact" eclipsing binaries.

The two components are so close together that they cannot be resolved with optical telescopes, forming a spectroscopic binary. In 2008, the primary star and the accretion disk of the secondary star were resolved and imaged using the CHARA Array interferometer and the Michigan InfraRed Combiner (MIRC) in the near infrared H band, allowing the orbital elements to be computed for the first time.

In addition to the regular eclipses, the system shows smaller and slower variations in brightness. These are thought to be caused by changes in the accretion disc and are accompanied by variation in the profile and strength of spectral lines, particularly the emission lines. The variations are not regular but have been characterised with a period of 282 days.

Beta Lyrae Aa is a semidetached binary system made up of a stellar class B6-8 primary star and a secondary that is probably also a B-type star. The fainter, less massive star in the system was once the more massive member of the pair, which caused it to evolve away from the main sequence first and become a giant star. Because the pair are in a close orbit, as this star expanded into a giant it filled its Roche lobe and transferred most of its mass over to its companion.

The secondary, now more massive star is surrounded by an accretion disk from this mass transfer, with bipolar, jet-like features projecting perpendicular to the disk. This accretion disk blocks humans' view of the secondary star, lowering its apparent luminosity and making it difficult for astronomers to pinpoint what its stellar type is. The amount of mass being transferred between the two stars is about 2 × 10⁻⁵ solar masses per year, or the equivalent of the Sun's mass every 50,000 years, which results in an increase in orbital period of about 19 seconds each year. The spectrum of Beta Lyrae shows emission lines produced by the accretion disc. The disc produces around 20% of the brightness of the system.

In 2006, an adaptive optics survey detected a possible third companion, Beta Lyrae Ab. It was detected at 0.54" angular separation with a differential magnitude of +4.53. The difference in magnitudes suggests its spectral class is in the range B2-B5 V. This companion would make Beta Lyrae A a hierarchical triple system.>>

Relevance?

[neufer]

Relevance?

Peterson has a rigid '"semanticsphere." (It is generally less rigid for most of the rest of us.)

Besides, I always need an excuse to post a Bonestell that I remember from my youth.