Archive for Astrophysics

A Free Online Course in Cosmology from SISSA

Posted in Education, The Universe and Stuff with tags , , , , on November 25, 2021 by telescoper

The nice people at the Scuola Internazionale Superiore di Studi Avanzati (known to its friends as SISSA for short) have made available a free online course in cosmology. You can get all of it on Youtube.

The course comprises 16 professionally edited video-lectures delivered by lecturers of the SISSA Astrophysical and Cosmology and Astroparticle PhD Programs and some of their collaborators. I know some of the participants personally, including Paulo Salucci (who introduces the course though I haven’t met him in person for ages so it was nice to see him on camera.

Cosmology is a big subject, of course, and a short-ish course can’t cover everything so there is an emphasis on the research topics covered by SISSA scientists. I haven’t watched all the videos but those I have seen are pretty good. There are actually 17 videos in the playlist below but that includes a very short prelude to introduce the series. The others are between about 25 and 45 minutes in length so you probably don’t want to watch them all in one sitting!

Astrophysics & Cosmology Masterclass – The Video!

Posted in Education, Maynooth, The Universe and Stuff, YouTube with tags , , , on November 15, 2021 by telescoper

As promised here is the video recording of the Astrophysics & Cosmology Masterclass we held by Zoom last Friday.

That Was The Masterclass That Was

Posted in Education, Maynooth, The Universe and Stuff with tags , , , on November 12, 2021 by telescoper

This morning we did the Astrophysics and Cosmology Masterclass advertised here. I think it went quite well. Apparently we had over sixty schools registered – at least one in every County – about a 1,000 schoolkids altogether. Certainly there were lots and lots of questions, which is a good sign!

Here is a screen grab of part of the event. I didn’t realize my camera was a bit wonky!

In case anyone is interested here are the slides I used for my part of the talk:

I’ll post a recording of the whole event when it becomes available. Here is the recording of the workshop:

I had to leave before the end to go to a vector calculus lecture that was interrupted by the arrival of the Power Rangers, but that’s a different story…

Astrophysics & Cosmology Masterclass at Maynooth!

Posted in Biographical, Education, Maynooth, The Universe and Stuff with tags , , on November 4, 2021 by telescoper

Regular readers of the blog – both of them – may remember that, after a couple of postponements due to Covid-19, we presented a Masterclass in Astrophysics & Cosmology in Maynooth on March 25th 2021. Well, owing to popular demand, we’ve decided to do a re-run of the event on Friday 12th November 2021 ahead of the forthcoming CAO cycle. That’s a week tomorrow!

This will be a half-day virtual event via Zoom. It’s meant for school students in their 5th or 6th year of the Irish system. There might be a few of them or their teachers who see this blog so I thought I’d share the news here. You can find more information, including instructions on how to book a place, here.

Here is the updated official poster and the programme:

I’ll be talking about cosmology early on, while John Regan will talk about black holes. After the coffee break one of our PhD students will talk about why they wanted to study astrophysics. Then I’ll say something about our degree programmes for those students who might be interested in studying astrophysics and/or cosmology as part of a science course. We’ll finish with questions either about the science or the study!

I’m told that with a week still to go we already have over 750 science students based in schools from An Daingean to Arranmore Island, from Monaghan to Mayo and many counties in-between. Fortunately it is online so no travelling is involved. Unfortunately the participants don’t get to see the wonderful campus so here’s a gratuitous picture!

(And at 12 noon I don’t turn into a pumpkin but do have to run off to give a lecture on vector calculus..)

Astrophysics & Cosmology Masterclass at Maynooth!

Posted in Biographical, Education, Maynooth, The Universe and Stuff with tags , , on September 28, 2021 by telescoper

Regular readers of the blog – both of them – may remember that, after a couple of postponements due to Covid-19,  we presented a Masterclass in Astrophysics & Cosmology in Maynooth on March 25th 2021. Well, owing to popular demand we’ve decided to do a re-run of the event on Friday 12th November 2021 ahead of next year’s CAO cycle.

This will be a half-day virtual event via Zoom. It’s meant for school students in their 5th or 6th year of the Irish system. There might be a few of them or their teachers who see this blog so I thought I’d share the news here. You can find more information, including instructions on how to book a place, here.

Here is the updated official poster and the programme:

I’ll be talking about cosmology early on, while John Regan will talk about black holes. After the coffee break one of our PhD students will talk about why they wanted to study astrophysics. Then I’ll say something about our degree programmes for those students who might be interested in studying astrophysics and/or cosmology as part of a science course. We’ll finish with questions either about the science or the study!

(And at 12 noon I don’t turn into a pumpkin but do have to run off to give a lecture on vector calculus..)

That was the Astrophysics & Cosmology Masterclass that was

Posted in Education, Maynooth, The Universe and Stuff with tags , , on March 25, 2021 by telescoper

I’m a bit late getting round to writing something on the blog today because it has been yet another hectic day. Between my usual lecture this morning and Computational Physics Laboratory session this afternoon we also had our long-awaited Astrophysics & Cosmology Masterclass (held via Zoom).

This event had been delayed twice because of Covid-19 so we were glad that it went ahead today at last!

We were a little nervous about how well it would go but as it happened I think it was a success. We had approaching a hundred schools tuning in, from Wicklow to Tralee, Longford to Monaghan, Donegal to Cork and many places between. The level of engagement was excellent. We held a question-and-answer session but were a little nervous in advance about whether we would actually get any questions. As it turned out we got a lot of questions with some very good ones among them. Reaction from students and teachers was very good.

For those who couldn’t make it to this morning’s session we did record the presentations and I’ll make the video available via YouTube in due course.

Now, I’ve been Zooming and Teaming (with a bit of Panopto thrown in) all day so if you don’t mind I’ll now go and vegetate.

Astrophysics & Cosmology Masterclass at Maynooth

Posted in Education, Maynooth, The Universe and Stuff with tags , , on February 23, 2021 by telescoper

Regular readers of the blog – both of them – may remember that we planned to present a Masterclass in Astrophysics & Cosmology on January 14th 2021 but this had to be postponed due to Covid-19 restrictions. After today’s announcements by the Government of  a phased return to school starting on March 1st we have now decided to proceed with a new date of March 25th 2021.

This will be a half-day virtual event via Zoom. It’s meant for school students in their 5th or 6th year of the Irish system, who should be returning to classrooms on March 15th, but there might be a few of them or their teachers who see this blog so I thought I’d share the news here. You can find more information, including instructions on how to book a place, here.

Here is the updated official poster and the programme:

I’ll be talking about cosmology early on, while John Regan will talk about black holes. After the coffee break one of our PhD students will talk about why they wanted to study astrophysics. Then I’ll say something about our degree programmes for those students who might be interested in studying astrophysics and/or cosmology as part of a science course. We’ll finish with questions either about the science or the study!

Physics versus Astrophysics

Posted in The Universe and Stuff with tags , on January 21, 2021 by telescoper

I don’t often post memes on here, but I couldn’t resist this one. Credit here.

On the Colours of Stars

Posted in The Universe and Stuff with tags , , , on January 20, 2021 by telescoper

There’s an interesting paper on the arXiv by Harre & Heller with the title Digital Color Codes of Stars. Here’s the abstract:

Publications in astrophysics are nowadays mainly published and read in digitized formats. Astrophysical publications in both research and in popular outreach often use colorful representations of stars to indicate various stellar types, that is, different spectral types or effective temperatures. Computer generated and computer displayed imagery has become an integral part of stellar astrophysics communication. There is, however, no astrophysically motivated standard color palette for illustrative representations of stars and some stars are actually represented in misleading colors. We use pre-computed PHOENIX and TLUSTY stellar model spectra and convolve them with the three standard color matching functions for human color perception between 360nm and 830nm. The color matching functions represent the three sets of receptors in the eye that respond to red, green, and blue light. For a grid of main sequence stars with effective temperatures between 2300K and 55,000K of different metallicities we present the red-blue-green and hexadecimal color codes that can be used for digitized color representations of stars as if seen from space. We find significant deviations between the color codes of stars computed from stellar spectra and from a black body radiator of the same effective temperature. We illustrate the main sequence in the color wheel and demonstrate that there are no yellow, green, cyan, or purple stars. Red dwarf stars (spectral types M0V – M9V) actually look orange to the human eye. Old white dwarfs such as WD1856+534, host to a newly discovered transiting giant planet candidate, occur pale orange to the human eye, not white. Our freely available software can be used to generate color codes for any input spectrum such as those from planets, galaxies, quasars etc.

This reminded me of a post I wrote in 2011 about why you never see any green stars. They say a picture paints a thousand words so here’s an illustration from the above paper:

This shows that although there are stars in the Main Sequence whose spectra peak at wavelengths corresponding to green light, none of them look green. The paper also claims that there are no yellow stars either. The Sun can look yellow when viewed from Earth but that is to do with scattering in the atmosphere: from space, the Sun looks white.

For another discussion of the use of colour representations in cosmology, see here.

 

Postponed: Astrophysics & Cosmology Masterclass at Maynooth

Posted in Education, Maynooth, The Universe and Stuff with tags , , on January 10, 2021 by telescoper

Regular readers of this blog may recall that the Department of Theoretical Physics at Maynooth University  planned to host a Masterclass in Astrophysics & Cosmology on January 14th 2021 (i.e. next Thursday). Unfortunately the closure of schools in Ireland until at least the end of January has given us no alternative but to postpone this event. It’s not cancelled though and we intend to run it as soon as possible: the date is now set provisionally for 25th February.  Limited places remain available and bookings are still open. You can find more information, including instructions on how to book a place, here.

Here is the official poster and the programme (timings still apply, but not the date..):

I’ll be talking about cosmology early on, while John Regan will talk about black holes. After the coffee break one of our PhD students will talk about why they wanted to study astrophysics. Then I’ll say something about our degree programmes for those students who might be interested in studying astrophysics and/or cosmology as part of a science course. We’ll finish with questions either about the science or the courses.

For updates please follow the Department’s on twitter-feed: