Archive for planet formation

Four New Publications at the Open Journal of Astrophysics

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , , on July 27, 2024 by telescoper

It’s Saturday morning, so once again it’s time for an update of activity at the Open Journal of Astrophysics. This week we have published another batch of four papers, the same number as last week, which takes the count in Volume 7 (2024) up to 64 and the total published altogether by OJAp up to 179.

Before announcing the week’s papers I’ll add three other updates you might find interesting:

  1.  When I looked at NASA/ADS this morning to help construct this post I saw that papers published in OJAp have now garnered over 2500 citations between them;
  2. We had a good response to our recent call for new members of the Editorial Board and have added four new members here;
  3. Last week we received a significant (unsolicited) cash donation from a higher education institution based in Europe to help with our work in Diamond Open Access. If any other organizations or individuals would like to do similar then please contact me!

Now, in chronological order, the four papers published this week, with their overlays, are as follows. You can click on the images of the overlays to make them larger should you wish to do so.

First one up is: “Widespread disruption of resonant chains during protoplanetary disk dispersal by Bradley M S Hansen (UCLA), Tze-Yeung Yu (UCLA) and Yasuhiro Hasegawa (JPL), all based in California, USA.  The paper presents a discussion of the effect of a dispersing protoplanetary disk on the evolution of low-mass planets around a Solar mass star.  It was published on 21st July 2024 and is in the folder marked Earth and Planetary Astrophysics.

Here is a screen grab of the overlay, which includes the abstract:

 

You can find the officially accepted version of the paper on the arXiv here.

The second paper to announce is “Using A One-Class SVM To Optimize Transit Detection” by Jakob Roche of the University of South Florida, also in the USA (but not in California). This articles discusses the advantages of One-Class Support Vector Machines (SVMs) over Convolutional Neural Networks (CNN) in the context of exoplanet detection. Its in the folder called Instrumentation and Methods for Astrophysics and was published on 25th July 2024.

You can see the overlay here:

 

 

 

The accepted version of this paper can be found on the arXiv here.

The next paper, also published on 25th July 2024, is in the folder marked High-Energy Astrophysical Phenomena. Its primary classification on arXiv is General Relativity and Quantum Cosmology (gr-qc), but it is cross-listed on astro-ph so we considered it for publication and had it refereed, with favourable results. It is entitled “What no one has seen before: gravitational waveforms from warp drive collapse” and is by Katy Clough (QMUL, UK), Tim Dietrich (Potsdam, Germany) and Sebastian Khan (Cardiff, UK).  Looking at the title of this paper you might be tempted to dismiss it on the grounds that warp drives are the stuff of science fiction (which they are), but this paper is really a rigorous technical study of the dynamical evolution and stability of spacetimes that violate the null energy condition, inspired by the idea of a warp drive.

Here is the overlay:

 

 

You can find the full text for this one on the arXiv here.

Last, published on 26th July 2024, we have a paper with the title “A study of gamma-ray emission from OJ 287 using Fermi-LAT from 2015-2023” by Vibhavasu Pasumarti and Shantanu Desai of the Indian Institute of Technology, Hyderabad, India. It is an investigation of the properties of gamma-ray emission from OJ287 (a BL Lac object) using the Fermi Large Area Telescope (LAT).  This one is also in the folder marked High-Energy Astrophysical Phenomena; here is the overlay

You can find the officially accepted version of this paper on the arXiv here.

That’s all for this week. Stay tuned for another update next week.

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Sub-Stellar Objects in the Euclid Early Release Observations

Posted in Euclid, The Universe and Stuff with tags , , , on May 31, 2024 by telescoper

I have a busy day in front of me here in Not-Barcelona so I thought I’d do a quick post sharing a video about the Euclid Early Release Observations (EROs) that came out last week. The press materials accompanying the release of the EROs and the science paper relating to this work, mention “freely floating planets”, but that doesn’t make sense in terms of the modern definition of a planet so here they are described as sub-stellar objects. The paper describing this work can be found on the arXiv here.

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R.I.P. Willy Kley (1958-2021)

Posted in Biographical, The Universe and Stuff with tags , , , on December 29, 2021 by telescoper

Once again it is my sad task to pass on news of the death of a colleague from the field of astrophysics. Prof. Dr. Wilhelm (“Willy”) Kley of the Institut für Astronomie & Astrophysik at the Universität Tübingen
in Germany passed away suddenly on 21st December 2021, at the age of 63.

Here is the official announcement (in German) from his institution:

Willy Kley was a computational astrophysicist who worked on accretion processes, especially in the context of the formation of planets and planetary systems. I knew him a little personally, as he was for a time in the Astronomy Unit at Queen Mary & Westfield College (as it was then called) at the same time I was there. He worked with the group led by John Papaloizou, alongside Richard Nelson and others, and I was working on cosmology, so we didn’t work together, but I did get to know him a bit and had a number of interesting discussions. He was a very nice man as well as a first-rate scientist. Looking at his (extensive) publication list it seems that he continued to collaborate with former QMW colleagues after his return to Germany in 2000.

His death was unexpected – I believe he suffered a heart attack – and I’m sure the news will come as a shock to many of his friends and collaborators. To them, and to his family, I send heartfelt condolences.

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Baby Planet Pictures…

Posted in Astrohype, The Universe and Stuff with tags , , on October 20, 2011 by telescoper

My eye was caught this morning by this dramatic picture on the front page of the Guardian website, linked to a story about the discovery of a very young planet:

I wonder how many people looking at it thought that it was an actual picture of a planet actually forming? In fact the above graphic is just an “artist’s conception” of the view near the planet, which is called LkCa 15b. The real picture is considerably less dramatic:

What you see is (left) a disk of dust and gas surrounding a star cleverly made visible by masking out the light from the star, which is much brighter than the disk.  On the right you can see a blow up of the inner region of the system, which appears to show a Jupiter-like planet associated with an irregular blob of material, out of which it probably condensed and from which it may still be accreting.

The size of the picture on the right is worth noting. The angle indicated is 76 milli-arcseconds. This is the angle subtended by  the  width of a  human hair at distance of about 130 metres…

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