APOD: Vela Supernova Remnant Mosaic (2019 Jan 10)

[APOD Robot]

Vela Supernova Remnant Mosaic

Explanation: The plane of our Milky Way Galaxy runs through this complex and beautiful skyscape. Seen toward colorful stars near the northwestern edge of the constellation Vela (the Sails), the 16 degree wide, 200 frame mosaic is centered on the glowing filaments of the Vela Supernova Remnant, the expanding debris cloud from the death explosion of a massive star. Light from the supernova explosion that created the Vela remnant reached Earth about 11,000 years ago. In addition to the shocked filaments of glowing gas, the cosmic catastrophe also left behind an incredibly dense, rotating stellar core, the Vela Pulsar. Some 800 light-years distant, the Vela remnant is likely embedded in a larger and older supernova remnant, the Gum Nebula. Objects identified in this broad mosaic include emission and reflection nebulae, star clusters, and the remarkable Pencil Nebula.

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[Ann]

This picture isn't new (I think), but it is one of my true astrophotography favorites.

Look at those amazing structures! Look at the "frothy", bluish bubbles! Look at those "structures upon structures", where young stars with and without accompanying reddish emission nebulas seem to be entangled inside filaments of two different supernova remnants. And look at the mighty, powerful blue binary star Gamma Velorum at lower right.

Wikipedia wrote:

The Gamma Velorum system is composed of at least four stars. The brightest member, γ² Velorum or γ Velorum A, is a spectroscopic binary composed of a blue supergiant of spectral class O7.5 (~30 M☉), and a massive Wolf-Rayet star (~9 M☉, originally ~35 M☉).[9] The binary has an orbital period of 78.5 days and separation varying from 0.8 to 1.6 astronomical units. The Wolf-Rayet star is likely to end its life in a Type Ib supernova explosion; it is one of the nearest supernova candidates to the Sun.

So we are probably looking at a supernova progenitor along with two superimposed supernova remnants in this great picture.

Ann

[Odysseus]

This photo is amazing, it hardly looks real!

[BDanielMayfield]

What are the names of the three brightest stars in today's APOD? (The yellow one on the left and the two blue stars on the right.)

[Chris Peterson]

What are the names of the three brightest stars in today's APOD? (The yellow one on the left and the two blue stars on the right.)

Courtesy of Astrometry.net. (Upper right zeta Pup = Naos, lower right gamma2 Vel = Regor)
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[Boomer12k]

Wonderful image...lots of detail...

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[zendae1]

I think I have seen some electrical discharges not dissimilar.

[neufer]

Chris Peterson: lower right gamma2 Vel = Regor

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<<Gamma Velorum (γ Vel, γ Velorum) is a multiple star system in the constellation Vela. At a combined magnitude +1.7, it is one of the brightest stars in the night sky, and by far the closest and brightest Wolf-Rayet star.

The γ Velorum system includes a pair of stars separated by 41", each of which is also a spectroscopic binary. γ2 Velorum, the brighter of the visible pair, contains a Wolf-Rayet star and a blue supergiant, while γ1 Velorum contains a blue giant and an unseen companion. It has the traditional name Suhail al Muhlif and the modern name Regor, but neither is approved by the International Astronomical Union.>>

Grissom, White, and Chaffee in front of the launch pad

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<<Apollo 1 was the first manned mission of the United States Apollo program. Planned as the first low Earth orbital test of the Apollo command and service module with a crew, to launch on February 21, 1967, the mission never flew; a cabin fire during a launch rehearsal test at Cape Kennedy Air Force Station Launch Complex 34 on January 27 killed all three crew members—Command Pilot Virgil I. "Gus" Grissom, Senior Pilot Ed White, and Pilot Roger B. Chaffee—and destroyed the command module. Apollo astronauts frequently aligned their spacecraft inertial navigation platforms and determined their positions relative to the Earth and Moon by sighting sets of stars with optical instruments. As a practical joke, the Apollo 1 crew named three of the stars in the Apollo catalog after themselves and introduced them into NASA documentation. Gamma Cassiopeiae became Navi – Ivan (Gus Grissom's middle name) spelled backwards. Iota Ursae Majoris became Dnoces – "Second" spelled backwards, for Edward H. White II. And Gamma Velorum became Regor – Roger (Chaffee) spelled backwards. These names quickly stuck after the Apollo 1 accident and were regularly used by later Apollo crews.>>

[BDanielMayfield]

What are the names of the three brightest stars in today's APOD? (The yellow one on the left and the two blue stars on the right.)

Courtesy of Astrometry.net. (Upper right zeta Pup = Naos, lower right gamma2 Vel = Regor)
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3139938.jpg

Thanks Chris. The yellow giant Suhail is interesting, being just under (probably) the mass needed to cause it to blow as a Supernova. Zeta Pup aka Naos is another matter however:

Zeta Puppis (ζ Puppis, abbreviated Zeta Pup, ζ Pup), also named Naos,[10] is a star in the constellation of Puppis.

The spectral class of O4 means this is one of the hottest, and most luminous, stars visible to the naked eye. It is one of the sky's few naked-eye class O-type stars as well as one of the closest to Earth.[6] It is a blue supergiant, one of the most luminous stars in the Milky Way. Visually it is over 10,000 times brighter than the Sun, but its high temperature means that most of its radiation is in the ultraviolet and its bolometric luminosity is over 500,000 times that of the Sun. It is also the 62nd brightest star in terms of apparent magnitude from Earth.

Naos is typical of O-type stars in having an extremely strong stellar wind, measured at 2,500 km/s,[11] which sees the star shed more than a millionth of its mass each year,[11] or about 10 million times that shed by the Sun over a comparable time period.

Ann, are ya slippin' just a little? How'd you miss this one? Surely you knew about it. You must have been short on time or something.

[Ann]

What are the names of the three brightest stars in today's APOD? (The yellow one on the left and the two blue stars on the right.)

Courtesy of Astrometry.net. (Upper right zeta Pup = Naos, lower right gamma2 Vel = Regor)
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3139938.jpg

Thanks Chris. The yellow giant Suhail is interesting, being just under (probably) the mass needed to cause it to blow as a Supernova. Zeta Pup aka Naos is another matter however:

Zeta Puppis (ζ Puppis, abbreviated Zeta Pup, ζ Pup), also named Naos,[10] is a star in the constellation of Puppis.

The spectral class of O4 means this is one of the hottest, and most luminous, stars visible to the naked eye. It is one of the sky's few naked-eye class O-type stars as well as one of the closest to Earth.[6] It is a blue supergiant, one of the most luminous stars in the Milky Way. Visually it is over 10,000 times brighter than the Sun, but its high temperature means that most of its radiation is in the ultraviolet and its bolometric luminosity is over 500,000 times that of the Sun. It is also the 62nd brightest star in terms of apparent magnitude from Earth.

Naos is typical of O-type stars in having an extremely strong stellar wind, measured at 2,500 km/s,[11] which sees the star shed more than a millionth of its mass each year,[11] or about 10 million times that shed by the Sun over a comparable time period.

Ann, are ya slippin' just a little? How'd you miss this one? Surely you knew about it. You must have been short on time or something.

I was indeed short of time, but... guess what? This very image, this APOD (which is not a new picture) along with reviewed Hipparcos parallaxes, made me just a little disappointed in Zeta Puppis. Not that it still isn't utterly amazing. But very long story short, I used to think that Zeta Puppis was both brighter and bluer than I now believe it is.

But really, it was this particular picture, this APOD (a version of which has been published before), that clinched it for me. Which of the two stars, Zeta Puppis or Gamma Velorum, looks more impressive? I had never before seen "the difference in power" between these two stars look so striking as it does in this picture. Maybe it's just because Gamma Velorum seems to be immersed in such a huge blue reflection nebula (which isn't there: Gamma Velorum isn't sitting in a reflection nebula).

Yes, I know. Zeta Puppis is a single star, which is quite remarkable for such a massive star, which are so often multiple. Of course, Zeta Puppis is a runaway star, which is the reason for its loneliness. The same thing is true for AE Auriga, Mu Columba and Zeta Ophiuchus. Gamma Velorum, the non-runaway, is a multiple star, as you would expect. But in a way it is its binarity that makes it so special, since its brightest component is made up of one O-type supergiant and one rare Wolf Rayet star.

So yes, I was short of time, and I decided that I would talk about the star that looked most amazing here, and there could be no doubt that the star in question would be Gamma Velorum.

Ann