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Using guard with foreman

I’ve been playing with Ruby quite a bit recently and I like the way a custom-looking DSL can be created from the same source language. This means I’ve converted a lot of my tools (e.g. Makefiles) into Rakefiles and I’ve just found foreman which can manage multiple subprocesses and combine their output into a nice looking coloured console result. This is typically used to manage web processes (server, task runner, development database etc.

Function fitting with lmfit

Scipy contains functions for fitting equations with Python, in its scipy.optimize module. The two main ones I’ve used in the past are leastsq and curve_fit, which in itself is a convenience wrapper around leastsq. curve_fit For this operation you require three (four) things: a function to fit of form f(x, *params) x data y data Optionally error data You can also supply an initial guess with the p0 argument.

Conference notes

This is not a blog post as such, it’s the notes that I took during the conference split up into sections. Unfortunately there is no reference to the talk content itself; this is kept in the booklet which I have sitting next to me as I type this. Session 1 Detecting and characterising via direct imaging More than 2Gyr gas giants more than 10^8 times fainter than primary Young stars are 10^4 - 10^7 times better than this Chronograph for increasing contrast Speckle noise a big problem for speckle based data S/N does not increase with time angular differential imaging speckles oscillate while image rotates, but keep similar shape real objects will move in the frame A stars good targets despite being bright higher hosting fraction for giant planets for A stars (not sure about this) high profile detections Nielsen show low host fraction despite this M stars also good targets despite low independent host fraction Typical contrasts - 10^5 at 1 arcsecond (with NICI) Physical properties (atmospheres) Direct photons detected from these objects reflected light and background contaminants surely?

Flight back

I’m currently on the plane back, flying over Canada at about 922km/h as the in-flight computer (android tablet in the back of the seat in front of me) says. I’m sitting next to a nice chinese couple, who don’t speak a word of English. They asked me through vague hand gestures to fill out their immigration card. It was quite an ordeal! Back home now after a good conference, got lots of nice pictures of Vancouver, but am quite tired now.

Last day

The last day has come and gone. I didn’t get time yesterday to write about it so I’m doing it now while I sit in front of the A-team in a Canadian hostel. As a side note this film looks terrible. We had some of the most interesting talks of the day yesterday, talking about planet migration and feasibility studies. Some cool stuff but I still don’t have a disc migration based theory to explain the Rossiter-McLaughlin effect.

Victoria museum

Today’s lectures were about… you guessed it: discs! A lot of people find them interesting apparently! Anyway the talks were ok, some good some bad. One in particular involved formation theories that seemed to explain the observed distributions well; I wanted to ask about selection effects but thought I’d find him afterwards. I didn’t have time in the end but it was very interesting. Coffee was taken up by talking to a postdoc at UNSW about dynamical stability.

Bike ride of the century

Today’s schedule was short, we had the afternoon off to do whatever we wished. Actually the conference organisers offered to put on a trip of some sort after a vote to find out the most popular choice, but that fell through as organising such a mammoth activity would be too difficult. This session was the most relevant to me and my work, as it involved the observational side of things. We had some great talks from some friends of mine, and other colleagues in the field.

Discs, discs and more discs

So today we learnt about discs, as the title of this post may suggest. We had protoplanetary discs (or proplyds which is a horrible portmanteau), thin discs, thick discs, transitional discs… This mostly involved theorists and simulations working their hardest, but we did get a few observational results thrown in for good measure. To be fair it’s a simulation type topic, current methods are not powerful enough without some serious and therefore expensive time on the largest telescopes.

First day

So the first day has just finished. We had some interesting talks (and some not so interesting, but that’s to be expected). The first session - before lunch - was dedicated to direct imaging, which is really taking off as a field, with advancements in technology and analysis tools since I last updated myself on the field. Being able to directly see protoplanetary disks is a new idea for me.

Victoria ferry

The ferry from Vancouver to Vancouver island (not Victoria island, as I’ve been told) was amazing. The scenery was breathtaking, photos of which I shall upload later. The little islands around Vancouver island were amazing to see, really fantastic. The map is centred on Victoria itself but the islands are to the north east. View Larger Map We’re sitting on a coach waiting to depart to Victoria town centre, ready to find our hotel and work out where the conference centre is.