NGC 2 - Measuring the Distance to Galaxies - Deep Sky Videos

Professor Mike Merrifield discusses methods for measuring the distance to NGC 2. Includes the Tully-Fisher method. More links and info in full description ↓↓↓
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A New Method of Determining Distances to Galaxies: ui.adsabs.harv...
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Video by Brady Haran and James Hennessy

[@MichaelEhling]

As ever, I feel I know this topic more completely after a DeepSky lesson from Professor Merrifield. Can we have a DeepSky dive into The Great Attractor?

[@TheMessiersAndromeda]

The channel SEA has an excellent video on the Great Attractor

[@rhoddryice5412]

Search “Paul Fellows Great Attractor”. He is a professor at Cambridge and has uploaded loads of lectures.

[@ericvosselmans5657]

@@TheMessiersAndromeda If you look drama and gloomy music.

[@feywild1758]

I was 15 when I discovered this channel. I'm 25 now. Thank you for continuing to make videos all of this time!

[@Jayc5001]

Remember to make a new playlist for the NGC catalog as well! I'm enjoying the videos, keep up this amazing content.

[@Jayc5001]

Also with new sky surveys coming online like Vera C. Rubin with the LSST I hope we can get a lot of 1A supernova distances to these galaxies.

[@MrMadsci7]

Thank you Dr. Merrifield for continuing to come back and teach us new things.

[@raideurng2508]

The great irony of the great attractor being in one of the most difficult areas of the sky to actually view past our galaxy.....

[@CanisMajor7]

Thank you for sharing your knowledge with us, professor!

[@patricescattolin43]

From the perspective of nice objects, you might want to look at the Arp catalog of peculiar galaxies. There is also a list of Finest NGC which are about nice to observe NGC. That would be one way to pick and choose in the NGC more intersting objects.

[@zapfanzapfan]

Episode 2 of the new 8000 part series. That's like the number of episodes of The Bold and the Beautiful, better get cracking with one episode a day! 🙂

[@andrewlabat9963]

Thank you for actually saying we'll probably never know for sure. The most scientificly honest thing I've heard in a while..

[@pratha1994]

Amazing video! I loved all the graphics and animation!

[@NoNameAtAll2]

2 done, 7838 to go

[@michaelsommers2356]

That should only take about 160 years. It's good to know we don't have to worry about running out of things to watch.

[@Jayc5001]

This is going to be quite the journey.

[@rhoddryice5412]

@@michaelsommers2356 48 days since NGC 1, if this pace is kept it would take 376000 days which is just about a thousand years.

[@michaelwhinnery164]

Now I want to see a post on the great attractor.

[@herblapp6134]

Michael l just read sbout the latest work studying Stephen's Quintet. It was presented today at the astro conference. Congrats on a new video it's been quiet awhile. 👍

[@MCPhssthpok]

That graphic at about 1:00 showing the redshift going from blue to red via violet!

[@raideurng2508]

Wait that's illegal.

[@logenninefinger3420]

Finally I knwo how the great attractor has been discovered. Nice!

[@peregrin71]

Goes to show, science is about dealing with uncertainties not absolutes (which most people seem to expect)

[@nabb111]

Love these videos. Could we get a video explaining why JWST images of nebula (like NGC 346) show no galaxies even in dark margins at the edges, and the deep field seem full of galaxies? Is it exposure time, settings used to create the images, that the light doesn’t make it through …? Seems perfectly on topic for this channel.

[@ApprendreSansNecessite]

This video is really perfect.

[@MT-ur5dp]

I will probably create images for the wikipedia articles of NGC objects. For the articles are missing images or have low quality images. Already added a better image for NGC 7.

[@iamsandrewsmith]

Last time, NGC 1. Tonight, NGC 2. This is going to keep you guys busy for a while.

[@vimalramachandran]

Very informative!

[@kemalm9383]

Would this need to be checked in different times of the year?

[@imager8763]

Love Mike's talks, sadly the volume on this video was all over the place.

[@3_letter_animal]

Ty for the video; qq, any plans on moving up from 1080p?

[@bbdonthurtme8163]

I've got a slight problem with what he said at 5:00. If the galaxy is rotating at the same rate, but much further away, wouldn't it NOT give the same answer due to it being further and therefore your rotational measurement would be shifted as well? Or would this be relative to the other side of the galaxy and still give the same difference.

[@benweieneth1103]

You measure the difference in velocity between the approaching and receding sides, so the overall motion of the galaxy cancels out.

[@bbdonthurtme8163]

@@benweieneth1103 Ah yes of course

[@brian_jackson]

I never hear it mentioned in videos and articles on the subject of measuring distances to galaxies, but is any account taken of any matter in intergalactic space that would slightly dim the galaxy's apparent brightness? I expect that the amount of matter is small, but over such huge distances, could that add up to a significant amount? There is probably little known about the matter between galaxies, but as far as I can tell, it is a assumed to be zero. Or is it?

[@michaelcollins966]

Yes, one of the many simplifications/assumptions made in astronomy. Which also leads to my unsatisfaction with the faithful belief in Dark Matter being an exotic material as yet undiscovered.

[@1.4142]

From what distance away from the great attractor are thing falling towards it faster than the expansion of the universe? As in given enough time they will end up in its neighborhood.

[@turboblazer]

This "Great Attractor" must be *massive* since gravity scales so poorly over long distances. How massive are we talking?

[@alansilverman8500]

The Tully-Fisher distances seem much more reasonable cause just by eyeballing it you can see they both have similar spacial resolution...

[@davidcampos1463]

Thank you, I did not have this.

[@thestrangegreenman]

"Small... Far away." "Uh huh" "Small... Far away." "Uhhh" "You get it?" "No, I don't think so."

[@SeanBZA]

When it comes to galaxies, it seems a million light years here, a million there all are tending to become small change...

[@coastwalker101]

Nice video. though not a Cepheid in sight.

[@simonsta]

Is there a galaxy where we see it neither blue shifted or red shifted?

[@culwin]

I think M98 is one of the least "shifted", but it is blue-shifted.

[@garethdean6382]

That's tricky. The problem is that we can detect VERY small shifts. We'd need to find a galaxy that's sitting almost still relative to us. And we can even detect the rotation of galaxies via the spread of their spectrum due to parts of the disk red and blue shifting.

[@dl5244]

no mention of systematic error...

[@kidmohair8151]

likingandcommenting to appease the algo-deities of the tube-u-all

[@OwenPrescott]

I think Deepsky should colab with Astrobiscuit (London based youtuber fyi)

[@phelliprd6659]

👍

[@LetMeRaveTV]

How do people know the red light from a galaxy is due to the universe expanding rather than the light from the galaxy just having a red hue?

[@vanhouten64]

NGC 1...NGC 2...lol, looks like they're actually gonna do it 😄

[@Corvaire]

I'm curious to know if the area of the great attractor's centralized area is also moving away from our perspective faster relative to other areas of expansion? In my Grand Fission Theory I describe our universe as a bubble being squeezed in the middle. If you turn that same analogy to look straight on to both sides being parallel (like two lenses in a telescope,) there would be a distant area that seems to draw inward. Because of the distance in conjunction with space time it would appear that a centralized point would emerge and be diluted showing only a slight movement to a particular area comparative to the rest of the universe. If true, this could also lead to more extreme lensing effects that could allow us to see multiple times farther back in space time. Just a thought. ;O)-

[@TheGokki]

What if the universe isn't expanding, but it's the photons that shift because they experience a tiiiiny bit of passage of time and they're not traveling at the maximum speed. They got no mass, but a tiny bit of energy - if the universe doesn't care about that distinction then (according to E=MC²) they would (in the vast distances and times) decay by having their frequency energy be spent on interacting with the Higgs field. Hypothesis: universe is not expanding, the photons interact extremely weakly with the higgs field over long distances/time and as a result their frequency lowers. Please correct me.

[@bnightm]

What you're describing is more broadly categorized as "Tired light" mechanisms to explain red shift. Wikipedia has a page on the history of the topic and it's current status.

[@TheGokki]

@@bnightm Oh cool, i'll check it out, neat.

[@garethdean6382]

An issue is that there's no real mechanism for photons to interact with the Higgs field in that way. The Higgs field isn't an energy sink for massive particles, they do not lose mass or energy to it over time. Another issue would be making sure that all photons lost the same percentage of energy over time, so that this sort of redshift wouldn't distort spectra. Which is tricky given that the Higgs field acts differently at higher energies. And of course, if there's gravity and the universe ISN'T expanding, something needs to stop it collapsing.

[@TheGokki]

@@garethdean6382 I wish i could sit down and talk to a cosmologist x)

[@Craznar]

What if time (like space) is 'expanding' as the universe gets older ? Wouldn't that disrupt the calculations ?

[@raideurng2508]

That'd break more than those calculations because it would potentially break special relativity.

[@Craznar]

@@raideurng2508 It wouldn't break SR any more than space expanding does.

[@erbalumkan369]

Redshift might not always be an indication of movement. See Halton Arp's work.

[@heywayhighway]

Nas

[@erbalumkan369]

Ever considered that your premise of an expanding universe might be false?

[@Lexivor]

Of course the astronomers have considered that. They've just rejected the hypothesis of a steady state universe.

[@BariumCobaltNitrog3n]

And the distance to other galaxies affects daily life on Earth how?

[@garethdean6382]

They aid us in the search for big truths, and can soothe us when we see that the merest whims of the powerful can decimate companies and lives for no real reason at all.

[@BariumCobaltNitrog3n]

@@garethdean6382 Decimate means to reduce your enemy's fighting force by 10% as proof of your superior power. But if you did know everything, and every big truth you would know that there is always a reason. Personally, I would not find that soothing. Truth is relative, not absolute, and is always what you believe it to be. But to the point here, knowing the distance to other galaxies will aid us in the search for big truths how?

[@mrmb84]

first

[@guderian557]

4 and a half "inch" telescope? It is not the dark ages anymore, use standard units of measurement.

[@abighairyspider]

Halton Arp