M47 - Strongly Magnetic White Dwarf - Deep Sky Videos

The open cluster Messier 47 contains a white dwarf star which attracted the interest of astronomers, as Mike Merrifield explains.
More links and info in full description ↓↓↓
Professor Merrifield is an astronomer at the University of Nottingham: / astromikemerri
PAPER... A Massive Magnetic Helium Atmosphere White Dwarf Binary in a Young Star Cluster: arxiv.org/abs/...
Messier Objects playlist: bit.ly/MessierO...
Deep Sky Videos website: www.deepskyvide...
Twitter: / deepskyvideos
Facebook: / deepskyvideos
More about the astronomers in our videos: www.deepskyvide...
Supported by the University of Nottingham
www.nottingham...
Back us on Patreon: / deepskyvideos
Video by Brady Haran

[@IanGrams]

I really love how much we can learn about such distant objects just from the light they absorb and emit. It'll never cease to amaze me.

[@grahams5871]

I love this Messier object series. Your scientists seem to dread it and think "Ugh, what interesting thing can I find about this boring object?" but they never fail to find something fascinating.

[@foowashere]

Yes, I agree-sometimes the most interesting things are in the details of the mundane.

[@michaelcollins966]

It’s amazing to see how much GAIA has changed astronomy. I remember at the beginning of this series, not knowing where stars were was a big obstacle. Now astronomers can just find all of the stars associated with a cluster with relative ease and do stuff like this.

[@Thelocalpsychopath]

Oooh nice astrophysical application of the Zeeman effect! Did a lab about it back in my Bachelor's but haven't seen it used in astrophysics before this. That's very neat!

[@flamencoprof]

What a pleasure it is to listen to someone who actually knows what they are talking about.

[@billyhendrix5544]

Best comment on KZbin 🎉

[@flamencoprof]

@@billyhendrix5544 Steady on!

[@MoonWeasel23]

Ah yes, Gaia numbers. Just casually numbering stars until a buffer overflow with the digits.

[@raptorbuff657]

I love this channel

[@uvofsam]

Now 108 is the only Messier object remaining

[@forthrightgambitia1032]

As someone who watched from the start, this is quite exciting.

[@AdDabrowski]

And M88

[@uvofsam]

Only 108 is remaining now

[@matgeezer2094]

Just subscribed to this channel, really informative. An astronomy channel that takes the viewer beyond the basics. Excellent, good stuff

[@JRizzo-li2dr]

Strongly magnetic white dwarf with a red dwarf companion. Sound like this might evolve into a Polar! Those are extremely fascinating objects in their own right!

[@litigioussociety4249]

I didn't know in Britain/Australia some people, maybe most pronounce Pleiades differently until now. In America it's usually plee-ades instead of ply-ades.

[@rhoddryice5412]

I wish in general we could be more true to the Greek pronunciations. Pleiades would be like Pley Ah dez (ey like in bay)

[@Deipnosophist_the_Gastronomer]

I don't think it matters too much. I'm pretty sure we can both understand each other enough to laugh at the pedants. :smile:

[@billyhendrix5544]

Very nice graph work. Can we get a glimpse into how things are plotted and graphed pleaseeeee Brady? I'm also from South Australia 230k from Adelaide xD

[@sasuna3085]

New video let's go

[@xja85mac]

At uni my professor would demonstrate the strength of an NMR machine by holding his keychain by the 1T magnet: it had lots of keys and a Swiss-army knife, and it would deflect by a few degrees.

[@theemissary1313]

We all remember the event horizon telescope image of the super massive black hole, but can we ever get a better image of a white dwarf binary where one str is stealing mass from it's neighbour? The artists' renditions are great and all, but i've always wondered if they actually look like that?

[@MountainFisher]

Look it up on Hubble. With my amateur telescope I cannot see any white dwarf, need a big professional one and Hubble has seen a dwarf star stealing from its neighbor. Plus plenty of radio telescopes. Most stars are in binary systems. Perhaps up to 85% of stars are in binary systems with some in triple or even higher-multiple systems. Look at the handle of the Big Dipper, the 2nd star from the end. It used to be an ancient eye test as there are two stars there name Mizar and Alcor, but with my 150mm telescope at 125x I can see a quadruple system of stars.

[@Migs3]

Impressive how scientists know all these things.

[@johnkotches8320]

Thank you for the mass diagram ... before that I was wondering how there could be a white dwarf in a young star cluster.

[@rhoddryice5412]

I think this is the list of remaining Messier object left: M61 - Spiral galaxy M72 - Globular M88 - Spiral galaxy M107 - Globular cluster M108 - Bared spiral galaxy

[@reluginbuhl]

Interesting! Nice explanation of the paper :)

[@thisnicklldo]

Amazing detective work - hats off to the scientists that have worked all this out over the last 100 years or so. Slightly puzzled by the bit at the end about the splitting of the helium spectral lines by magnetic effects. I thought that the point about white dwarfs was that they had run out of helium, and are mostly composed of carbon, oxygen etc i.e the products of fusion that this mass of star cannot further fuse. Is the helium detected just small traces left over, and even if it is, why doesn't it undergo fusion in the centre of this very massive if small object?

[@thisnicklldo]

@@mairiobrien7276 Makes sense

[@unvergebeneid]

It doesnt cease to amaze me how much we can learn about the universe despite being stuck on this tiny rock!

[@chrissscottt]

Made me laugh when Professor Merrifield said, "Stars never put on weight".

[@NoNameAtAll2]

the man said we can detect how long dwarf lived as dwarf (and thus the death date of the original star), but how precise was birth of that star dated? like "150million" plus-minus how much? and how much let's say 1 million changes the supposed mass of original star?

[@MushookieMan]

IIRC this all comes from the "cosmic distance ladder" and various physical models. I don't think it's very precise.

[@NoNameAtAll2]

@@MushookieMan distance ladder is about determining distance - it's in the name question here is more about time

[@rhoddryice5412]

Listen to the professor again.

[@garethdean6382]

The uncertainty in the dwarf's cooling time and the cluster's age combine to be a few million year's worth of uncertainty. This can be seen in the graph at around 4:40, where the error bars are marked out for every star. You can see it's significant, but not enough to obscure the general picture.

[@guyh3403]

Thank you very much!

[@iugoeswest]

Sweet. Thanks

[@redapplefour6223]

no clue how i noticed the 3 birds fly by out the window at 8:33

[@rad858]

magpies!

[@phil1963100]

Fascinating.

[@banzaiib]

how do you know the difference between color of the star and velocity toward / away?

[@rhoddryice5412]

Every element got its unique spectral lines and they get shifted towards red if the object moves away from you and towards blue if it moves towards you.

[@cemoguz2786]

why the massive star that shed outer layer have more magnetic power? is it because it spins fastter? I am asking that because you said massive stars will have smaler cores so that means when they get to be only core then maybe it spins faster because they are being smaler then typical.

[@cemoguz2786]

I am talking about conservation of angular momentum.

[@droppedpasta]

At 0:27, what’s the ring on the left of the screen?

[@garethdean6382]

A light artifact, you can see another one a little down and to the right, just touching the left side of the central star's horizontal bar.

[@droppedpasta]

@@garethdean6382 Thanks!

[@MrJimtimslim]

I get the impression Mike is slightly more intelligent than I am 😄🤪

[@الرجلالطيب-ط7ض]

سبحان الله وبحمده سبحان الله العظيم

[@1.4142]

Pulsars can have magnetic field of up to one billion Teslas!

[@matgeezer2094]

Yeah, neutron stars are utterly mental. I think they are more interesting than black holes personally, cause black holes don't give anything back (apart from accretion disks of course)

[@SharpAssKnittingNeedles]

Ok I've watched this vid a few times like all the others on this channel, Brady. And what a masterpiece! Amazing that a dim lil thing like a white dwarf is perceptible to a relatively dim satellite like Gaia! 🎉 So cool! And it might just be an imaging aberration, but seems like you can almost see the companion in that imagery! 🥰 Wow so cool!

[@thinkbolt]

M-dwarf??

[@simontmn]

red dwarf

[@theserbian]

How can a 75 million old, 6 times the mass of sun star make a white dwarf? The limit is 1.4 mass. Everything above that is either neutron star or black hole.

[@rhoddryice5412]

Stars up to about 8Msun expands at the end of their life and throws of a lot of mass. In the end only the core is left and slowly will cool down. Above 8Msun the pressure isn’t enough and instead it collapses and explodes throwing away excess mass and forming a neutron star or if heavy enough a black hole.

[@TheLonelyTraveler142]

The Chandrasekhar limit is a limit on the mass of the white dwarf, not the mass of its originating star. The white dwarf is only a small portion of the star's mass

[@theserbian]

@@rhoddryice5412 I thought I knew it all. Thanks for the clarification!

[@theserbian]

@@TheLonelyTraveler142 Thanks for the answer!😀

[@matgeezer2094]

I knew a star lost mass in the planetary nebula phase, but I didn't know it was so much

[@Thunder_Dome45]

How can an average Joe get these papers without paying a bunch of money for them? Like a monthly subscription?

[@runabath]

75million years I mean how do u fit all those candles on the cake😳

[@rhoddryice5412]

You have to make a big enough cake. =)

[@runabath]

How does a star start naturally when we can't make one, can't be hard😳

[@ryanchan153]

compression of gas clouds

[@Deipnosophist_the_Gastronomer]

Well it's not so much a science problem as an engineering one.