LMC S154 is a symbiotic recurrent nova, study suggests

**LMC S154 is a symbiotic recurrent nova, study suggests
Spectral variability of LMC S154. Credit: Iłkiewicz et al., 2019.

Astronomers have conducted observations of a symbiotic star in the Large Magellanic Cloud (LMC), known as LMC S154, which provide new insights about the nature of this object. Results of these observations, presented in a paper published February 7 on arXiv.org, suggest that LMC S154 is a symbiotic recurrent nova—the first such object identified in Magellanic Clouds.

Symbiotic stars (SySts) are in general long-period interacting binaries consisting of an evolved giant transferring mass to a hot compact object – usually a late-sequence red giant providing material to a white dwarf. One type of SySts are symbiotic novae (SyNe) in which experience thermonuclear explosions on their surface. When these occur in SyNe more than once, astronomers classify such objects as symbiotic recurrent novae (SyRNe).

SyRNe are extremely rare and to date only four objects of this subclass have been detected. One potential candidate for a new SyRN is LMC S154, an X-ray source in the LMC classified as an SySt. Although previous studies of LMC S154 show that its variability resembles that of symbiotic novae, its SyNe status still remains unconfirmed. This is mainly due to the significant gap in photometric observations of LMC S154 ranging from 1950s to 1980s, and also due to lack of studies of this source in its quiescence.

In order to clarify the nature of LMC S154, a group of astronomers led by Krystian Iłkiewicz of Nicolaus Copernicus Astronomical Center in Poland has conducted photometric and spectroscopic monitoring of this binary with the main aim of determining the timescales of its variability. Results from this observational campaign and analysis of archival data allowed the scientists to identify with the most confidence three outbursts from the studied object.

"In this work, we study the possible evidence for the nova outburst of LMC S154. (…) The data indicate that most probably, there were three outbursts observed in LMC S154, which would make this system a member of a rare class of symbiotic recurrent novae," the researchers wrote in the paper.

According to the study, archival data, mainly carbon abundance in the photosphere of the red giant as well as luminosity and temperature changes of the white dwarf, confirm that the variability of LMC S154 is due to a classical nova outburst. Additionally, new observations show that the outburst ended in 2009, the system reached its quiescent state, and that all phases of the outburst were observed. This proves that the binary is, indeed, a symbiotic nova.

Furthermore, analysis of archival data suggests that there has been more than one outburst recorded in the history of the system. This assumption is based on the detection of doubly ionized oxygen lines between the two observed maxima in the 1940s and in the 1980s, and their the non-detection in the 1980s.

"These lines are characteristic of the nebular phase of outburst, and once detected, they last until the end of outburst, even if more than one maximum of the outburst is present (see e.g., RX Pup). This means that the maxima detected in the 1940s and the 1980s were associated with two different outbursts, and that each of them was followed by a nebular phase," the researchers explained.

They added that the detection of iron coronal lines and the observed X-ray radiation in the archival data from 1980s also support the hypothesis that LMC S154 is a SyRNe. If the theory presented in the paper is true, it would make LMC S154 the first SyRN in Magellanic Clouds and in general the third recurrent nova in the LMC.


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More information: Krystian Ilkiewicz et al. LMC S154: the first Magellanic symbiotic recurrent nova. arXiv:1902.02621 [astro-ph.SR]. arxiv.org/abs/1902.02621

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Citation: LMC S154 is a symbiotic recurrent nova, study suggests (2019, February 21) retrieved 26 May 2019 from https://phys.org/news/2019-02-lmc-s154-symbiotic-recurrent-nova.html
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Feb 21, 2019
This observation fits well with the Suspicious Observers community proposal of the Earth Catastrophe Cycle.
https://www.youtu...3APVS8br

Feb 21, 2019
@CDskiperror: Any source that supports a Noachian Global Flood is fatally suspect, given NGF's original authors totally plagiarised it from the much earlier 'Gilgamesh' tradition.

yep
Feb 22, 2019
@CDskiperror: Any source that supports a Noachian Global Flood is fatally suspect, given NGF's original authors totally plagiarised it from the much earlier 'Gilgamesh' tradition.

You and your up voters, without knowledge of the reference material presented, assumed you knew something. In doing that you miss opportunity to learn. This is why science advances by death of the old, the young are eager to learn.

Feb 22, 2019
@yep,

@CDskiperror: Any source that supports a Noachian Global Flood is fatally suspect, given NGF's original authors totally plagiarised it from the much earlier 'Gilgamesh' tradition.

You and your up voters, without knowledge of the reference material presented, assumed you knew something. In doing that you miss opportunity to learn. This is why science advances by death of the old, the young are eager to learn.


I do know something, and "Suspicious Observers" need to be suspicious of themselves, not suspicious of modern science. Suspicious Observers come to conclusions, then cherry pick and mutilate data to support their conclusions.

The young don't need to learn to do that; they do need not to learn to do that.

Our Sun has never gone nova, and almost certainly never will.

Feb 22, 2019
Our Sun has never gone nova, and almost certainly never will.

Super-flares are most certainly a possibility.

Any source that supports a Noachian Global Flood is fatally suspect, given NGF's original authors totally plagiarised it from the much earlier 'Gilgamesh' tradition.

You assume using skewed data that your claims are valid. The idea here is that these floods (one or more) have occurred on Earth and man has witnessed the events.

Feb 22, 2019
You assume using skewed data that your claims are valid. The idea here is that these floods (one or more) have occurred on Earth and man has witnessed the events.


Then there should be good scientific evidence for such things. Where is it?

Feb 22, 2019
@cantdrive85,

Our Sun has never gone nova, and almost certainly never will.

Super-flares are most certainly a possibility.


A "super-flare" is actually a "coronal mass ejection" (CME); they occur frequently, but, fortunately, are rarely projected toward Earth. One struck in 1859 that took out all of North America's telegraph lines.

A CME can be extremely serious -- even civilization destroying -- but has nowhere near the destructive power of a nova event. A nova (unlike a supernova) occurs when a white dwarf's gravity pulls enough mass from its companion star (generally a red giant) onto itself that a huge nuclear fusion explosion takes place over its entire surface due to gravitational compression; a white dwarf is a collapsed dead star close to the size of Earth that has a center of mostly carbon and is not undergoing nuclear fusion. A nova event is greater than even the largest CME by many orders of magnitude.

Feb 22, 2019
A nova (unlike a supernova) occurs when a white dwarf's gravity pulls enough mass from its companion star (generally a red giant) onto itself that a huge nuclear fusion explosion takes place over its entire surface due to gravitational compression; a white dwarf is a collapsed dead star close to the size of Earth that has a center of mostly carbon and is not undergoing nuclear fusion.

This is 100% conjecture, not a single fact included.

A nova event is greater than even the largest CME by many orders of magnitude.

A Carrington type event isn't an extinction event, millions if not billions could die but only due to our electronic society. Life would continue unfettered.
A super-flare would be something between the largest observed CME and a nova. It could reshape the surface, induce these purported floods, and cause mass extinction.

yep
Feb 23, 2019
Then there should be good scientific evidence for such things. Where is it?

Do you even think before you type. How much scientific evidence and how many traditional stories do you need, you obviously have never looked into the scientific data because that statement of ignorance is glaring.

Yes the young definitely need to be open to learning through out their lives otherwise they will end up old fools like you wankers unable to admit error or lack of knowledge. New century catch up.

Feb 23, 2019

A nova event is greater than even the largest CME by many orders of magnitude.

A Carrington type event isn't an extinction event, millions if not billions could die but only due to our electronic society. Life would continue unfettered.


Who said anything about an extinction event? I said civilization-ending, entirely because of our electronic and electric society. But yes, billions would die. You need to think more carefully about our electronic and electric society. It could easily take 50 years to get everything back up and running. In the meantime, what happens to food production, storage, and distribution? Billions would die.

Life would not continue "unfettered."

A super-flare would be something between the largest observed CME and a nova. It could reshape the surface, induce these purported floods, and cause mass extinction.


100% conjecture; not a single fact included.

Feb 23, 2019
Life would not continue "unfettered."

Humans would suffer, society would suffer due to our electronic society, ignorance, and self-inflicted condition. But this would not affect living organisms as a whole. If it weren't for the 4 or 5 casualties of telegraph operators and pretty aurora we would have never even known the Carrington event occurred.
A super-flare would be something between the largest observed CME and a nova. It could reshape the surface, induce these purported floods, and cause mass extinction.

100% conjecture; not a single fact included.

No doubt, except for the repeated extinction events, observed floods, and numerous unexplained geologic formations/anomalies.

Feb 23, 2019
No doubt, except for the repeated extinction events, observed floods, and numerous unexplained geologic formations/anomalies.


Balderdash.


Feb 23, 2019
nik, obs, jd, you are debating crazed loons with the intellectual quality of termite-ridden fenceposts.

If you find the effort tiresome or have some other important work to do?

Just let me know & I will gleefully takeover belaboring the fakirs with my mighty brickbat made from their ignorance.

No, no! No charge. I am a generous sadist & will take great pleasure in caning this pair of masochist submissives.

For some reason their "Naughty Little Girl begging for a spanking" act, really brings out the Big Gruff Daddy in me?

Though I gotta say, they look mighty cute all dressed up in their best pinafores. With their mary-janes nicely shined & their be-ribboned curls dangling from their bonnets.

Feb 23, 2019
Life would not continue "unfettered."

Humans would suffer, society would suffer due to our electronic society, ignorance, and self-inflicted condition. But this would not affect living organisms as a whole. If it weren't for the 4 or 5 casualties of telegraph operators and pretty aurora we would have never even known the Carrington event occurred.


I gather you're ready to give up modern society, including medical care.

100% conjecture; not a single fact included.

No doubt, except for the repeated extinction events, observed floods, and numerous unexplained geologic formations/anomalies.


Repeated extinction events are well explained without magic solar super-flares for which there are no theoretical or empirical bases.

Plenty of floods followed the end of the recent glacial epoch. Rising sea levels cause flooding. That's currently being observed.

To which geological anomalies and unexplained formations are you referring?

Feb 23, 2019
@rrwillsj,

The offer is appreciated; go for it. I'm going to keep correcting them, as well -- people who can point out errors should do so, as this is a science site. Errors should be corrected.

Being retired, disabled, and almost sixty-nine years old, I really don't have to be anywhere, so I have plenty of time. It's true that I need a cane, only, to walk, but riding in an automobile is painful, and the only things within walking distance are my front and back yards, and my neighbors' houses.

I don't get out, much.

Feb 23, 2019
To which geological anomalies and unexplained formations are you referring?


Probably referring to the Grand Canyon, which the clueless EUists think was carved out by a giant lightning bolt, possibly around the time that Venus was right up our collective backsides, as per the loon Velikovsky. Not only the Grand Canyon, by the way, but Valles Marineris, no less! Possibly also contemporaneous with Venus doing handbrake turns around the solar system.

Feb 23, 2019
Ah, Velikovsky. Now that previously personally perplexing position makes sense, even though the assertion, itself, does not.

It's amazing, but believable, what a river can do to limestone, sandstone and shale over a few million years. Lightning, not so much.

Feb 23, 2019
Veloskypilot, Pththpp!

I much prefer the theosophist hollow earth. So I can ride a dinosaur just like those displayed at the jeebus cult museums with authentic dioramas of Alley Oop riding a dinosaur.

Sign up for the package tour & you get to kangaroo there in an aetherplasmoid wheeled flying daucer!

Feb 24, 2019
I'll just play with my pet dinosaur (an Amazon parrot); well, actually, her direct ancestors are dinosaurs, but she takes pride in her ancestry and insists on being referred to as a dinosaur, so I humor her; there's no reason not to (she loves to talk with me).

yep
Mar 08, 2019
nik, obs, jd, you are debating crazed loons with the intellectual quality of termite-ridden fenceposts.

If you find the effort tiresome or have some other important work to do?

Just let me know & I will gleefully takeover belaboring the fakirs with my mighty brickbat made from their ignorance.

No, no! No charge. I am a generous sadist & will take great pleasure in caning this pair of masochist submissives.

For some reason their "Naughty Little Girl begging for a spanking" act, really brings out the Big Gruff Daddy in me?

Though I gotta say, they look mighty cute all dressed up in their best pinafores. With their mary-janes nicely shined & their be-ribboned curls dangling from their bonnets.


Some projection coupled with feelings of inadequacy. Got to wonder who really wants the spanking here.

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