APOD: RCW 114: A Dragon's Heart in Ara (2018 Jan 11)

[APOD Robot]

RCW 114: A Dragon's Heart in Ara

Explanation: Large and dramatically shaped, this cosmic cloud spans nearly 7 degrees or 14 full moons across planet Earth's sky toward the southern constellation Ara. Difficult to image, the filamentary apparition is cataloged as RCW 114 and traced in this telescopic mosaic by the telltale reddish emission of ionized hydrogen atoms. In fact, RCW 114 has been recognized as a supernova remnant. Its extensive filaments of emission are produced as the still expanding shockwave from the death explosion of a massive star sweeps up the surrounding interstellar medium. Consistent estimates place its distance at over 600 light-years, indicating a diameter of about 100 light-years or so. Light from the supernova explosion that created RCW 114 would have reached Earth around 20,000 years ago. A neutron star or pulsar has recently been identified as the collapsed remains of the stellar core.

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[/b]

[Boomer12k]

"20,000 years old", and it still looks "Angry"....

If you used other filters, would you see other elements from the SN? Oxygen? for example? Or has that all dissipated too much?

Wonderful image job...
:---[===]*

[Ann]

"20,000 years old", and it still looks "Angry"....

If you used other filters, would you see other elements from the SN? Oxygen? for example? Or has that all dissipated too much?

Wonderful image job...
:---[===]*

Good question, Boomer. I, too, wonder why the supernova remnant is so red.

But maybe it doesn't have the energy required to ionize oxygen any more.

Ann

[stolenmoment]

Is the remnant even in the frame? Might it even be visible?

[starsurfer]

"20,000 years old", and it still looks "Angry"....

If you used other filters, would you see other elements from the SN? Oxygen? for example? Or has that all dissipated too much?

Wonderful image job...
:---[===]*

This one is strange that it doesn't have any OIII.

[starsurfer]

"20,000 years old", and it still looks "Angry"....

If you used other filters, would you see other elements from the SN? Oxygen? for example? Or has that all dissipated too much?

Wonderful image job...
:---[===]*

Good question, Boomer. I, too, wonder why the supernova remnant is so red.

But maybe it doesn't have the energy required to ionize oxygen any more.

Ann

A challenge for Ann, find the two globular clusters!

[starsurfer]

Is the remnant even in the frame? Might it even be visible?

The filaments visible in the image are the remnant of the star that exploded as a supernova.

[starsurfer]

RCW 114: A Dragon's Heart in Ara

Explanation: Large and dramatically shaped, this cosmic cloud spans nearly 7 degrees or 14 full moons across planet Earth's sky toward the southern constellation Ara. Difficult to image, the filamentary apparition is cataloged as RCW 114 and traced in this telescopic mosaic by the telltale reddish emission of ionized hydrogen atoms. In fact, RCW 114 has been recognized as a supernova remnant. Its extensive filaments of emission are produced as the still expanding shockwave from the death explosion of a massive star sweeps up the surrounding interstellar medium. Consistent estimates place its distance at over 600 light-years, indicating a diameter of about 100 light-years or so. Light from the supernova explosion that created RCW 114 would have reached Earth around 20,000 years ago. A neutron star or pulsar has recently been identified as the collapsed remains of the stellar core.

<< Previous APOD

This Day in APOD

Next APOD >>

[/b]

While a large part of RCW 114 is in Ara, I think the exact centre is in Scorpius.

Also John Gleason would be proud!

[stolenmoment]

Is the remnant even in the frame? Might it even be visible?

The filaments visible in the image are the remnant of the star that exploded as a supernova.

Sorry, I meant the pulsar that's what's left of the star...

[neufer]

<<RCW 114's filamentous and widespread aspect has immediately directed the astronomers towards the theory according to which at the origin of this structure there could be the explosion of a supernova , therefore it was cataloged as a supernova remnant , with the initials SNR G343.0 -06.0; its distance, based on the observation of the 7-star absorption lines aligned with it, was estimated around 200 parsecs, a value that, if it were correct, would make it the nearest supernova remnant in absolute to the solar system , while the diameter was estimated around 17.5 parsec or less.

Subsequently, through the analysis of the Hipparcos satellite data and the reanalysis of the available data, it was suggested that this cloud could be, instead, a distant giant (~470 ly) bubble generated by the powerful star-wind of Wolf-Rayet HD 156385, also known as WR 90; this hypothesis would also be confirmed by other indications, such as the presence of a neutral hydrogen (HI) envelope, often present around the Wolf-Rayet stars. The absorption lines of some elements, such as and [N II], could be due to the presence of a superbolla already existing previously, probably caused by the explosion of a supernova.>>

[starsurfer]

Also try finding it in this mosaic by John Gleason!

It can be found in this mosaic by Gerald Rhemann.

[Chris Peterson]

While a large part of RCW 114 is in Ara, I think the exact centre is in Scorpius.

How do you define the "exact centre"? The center of this image is certainly in Ara, as is the remnant parent star.

[HunterofPhotons]

Is the remnant even in the frame? Might it even be visible?

The filaments visible in the image are the remnant of the star that exploded as a supernova.

Sorry, I meant the pulsar that's what's left of the star...

It's in the field of view although I'm not sure if it's visible.
Click on the 'identified' link in today's text and in the referenced paper the remnant's location is noted.

dan kowall

[Ann]

"20,000 years old", and it still looks "Angry"....

If you used other filters, would you see other elements from the SN? Oxygen? for example? Or has that all dissipated too much?

Wonderful image job...
:---[===]*

Good question, Boomer. I, too, wonder why the supernova remnant is so red.

But maybe it doesn't have the energy required to ionize oxygen any more.

Ann

A challenge for Ann, find the two globular clusters!

I can only find one, near bottom, at about 5 o'clock. It is very obvious. But as for the other one... nope!

So help me, okay, starsurfer?

Ann

[neufer]

RCW 114: A Dragon's Heart in Ara

Explanation: Consistent estimates place its distance at over 600 light-years, indicating a diameter of about 100 light-years or so. Light from the supernova explosion that created RCW 114 would have reached Earth around 20,000 years ago. A neutron star or pulsar has recently been identified as the collapsed remains of the stellar core.>>

Proper motion of the radio pulsar B1727-47 and its association with the supernova remnant RCW 114
P. Shternin, M. Yu, A. Kirichenko, Yu. Shibanov, A. Danilenko, M. Voronkov, D. Zyuzin
(Submitted on 4 Nov 2017 (v1), last revised 20 Dec 2017)

Conclusions: The radio pulsar B1727-47 proper motion vector v_⊥ points at the center of the SNR RCW 114, suggesting SNR–PSR association. In this case the most plausible distance to the system is ~700pc
[~2,300 ly] and the p.m. based age is 60−80 kyr, compatible with the pulsar characteristic age.

Assuming D≈700pc, we find v_⊥≈500 km/s
[for a total angular displacement of ~3º].

[Andy01]

"20,000 years old", and it still looks "Angry"....

If you used other filters, would you see other elements from the SN? Oxygen? for example? Or has that all dissipated too much?

Wonderful image job...
:---[===]*

Hi Boomer - I tried using an O3 filter but there was virtually no signal present - I understand that there may be some S2 though.
Cheers

Andy

[Andy01]

Good question, Boomer. I, too, wonder why the supernova remnant is so red.

But maybe it doesn't have the energy required to ionize oxygen any more.

Ann

A challenge for Ann, find the two globular clusters!

I can only find one, near bottom, at about 5 o'clock. It is very obvious. But as for the other one... nope!

So help me, okay, starsurfer?

Ann

Hi Ann, Look for NGC 6388 - to the far left of the frame at 10 O'clock.
Cheers

Andy

[Ann]

A challenge for Ann, find the two globular clusters!

I can only find one, near bottom, at about 5 o'clock. It is very obvious. But as for the other one... nope!

So help me, okay, starsurfer?

Ann

Hi Ann, Look for NGC 6388 - to the far left of the frame at 10 O'clock.
Cheers

Andy

Wow, thanks a lot, Andy! NGC 6388 is a bright yellow thing that looked like a star to me! Admittedly, it is a bit fuzzy at the edges.

That means that the other globular, at about 5 o'clock scraping the bottom of the picture frame, is NGC 6352. And the moderately bright bluish star at 8 o'clock is Sigma Ara. And that moderately bright bluish star at about 5 o'clock (but pretty centrally located) is Iota Ara. And the bluish "double star" located almost dead center of the supernova remnant is SAO 227972 (the brighter component) and SAO 227966 (the fainter component. The stars appear to have very similar proper motions and possibly parallaxes, so they may be physically related.

None of those two stars is a supernova remnant, that's for sure!

Ann

[starsurfer]

I can only find one, near bottom, at about 5 o'clock. It is very obvious. But as for the other one... nope!

So help me, okay, starsurfer?

Ann

Hi Ann, Look for NGC 6388 - to the far left of the frame at 10 O'clock.
Cheers

Andy

Wow, thanks a lot, Andy! NGC 6388 is a bright yellow thing that looked like a star to me! Admittedly, it is a bit fuzzy at the edges.

That means that the other globular, at about 5 o'clock scraping the bottom of the picture frame, is NGC 6352. And the moderately bright bluish star at 8 o'clock is Sigma Ara. And that moderately bright bluish star at about 5 o'clock (but pretty centrally located) is Iota Ara. And the bluish "double star" located almost dead center of the supernova remnant is SAO 227972 (the brighter component) and SAO 227966 (the fainter component. The stars appear to have very similar proper motions and possibly parallaxes, so they may be physically related.

None of those two stars is a supernova remnant, that's for sure!

Ann

Well done Ann! Your prize has been sent to you!

[starsurfer]

While a large part of RCW 114 is in Ara, I think the exact centre is in Scorpius.

How do you define the "exact centre"? The center of this image is certainly in Ara, as is the remnant parent star.

Actually I only made the comment to see how people would respond.

[Andy01]

Hi Ann, Look for NGC 6388 - to the far left of the frame at 10 O'clock.
Cheers

Andy

Wow, thanks a lot, Andy! NGC 6388 is a bright yellow thing that looked like a star to me! Admittedly, it is a bit fuzzy at the edges.
Ann

Hey Ann, check out the image in high res here - https://www.astrobin.com/full/328424/0/

[Ann]

It still looked a bit stellar to me in the high-res full frame image.

But you also posted a few closeup pictures of NGC 6388, and in those images there could be no doubt of the globular nature of NGC 6388!

Ann

[Case]

The radio pulsar B1727-47 proper motion vector v_⊥ points at the center of the SNR RCW 114, suggesting SNR–PSR association. In this case the most plausible distance to the system is ~700pc [~2,300 ly] and the p.m. based age is 60−80 kyr, compatible with the pulsar characteristic age.

Assuming D≈700pc, we find v_⊥≈500 km/s
[for a total angular displacement of ~3º].

That is much father out than I would have looked, based on observations where the associated star is so often near the center. Would the interstellar medium slow down the proper motion of the expanding SNR by that much? That would seem like quite a strong brake! Or are there other forces to consider?

[neufer]

The radio pulsar B1727-47 proper motion vector v_⊥ points at the center of the SNR RCW 114, suggesting SNR–PSR association. In this case the most plausible distance to the system is ~700pc [~2,300 ly] and the p.m. based age is 60−80 kyr, compatible with the pulsar characteristic age. Assuming D≈700pc, we find v_⊥≈500 km/s
[for a total angular displacement of ~3º].

That is much father out than I would have looked, based on observations where the associated star is so often near the center. Would the interstellar medium slow down the proper motion of the expanding SNR by that much? That would seem like quite a strong brake! Or are there other forces to consider?

After ~70,000 years the radial motion of the expanding SNR is hundreds of times slower than it's initial ~30,000 km/s velocity (after having picked up hundreds of times additional mass). It appears that radio pulsar B1727-47 has not only caught up with its SNR but has plowed through it leaving a radiation induced wake behind. You can't compare this situation with more recent supernovae where almost all the displacement involves the SNR.