Archive for the ‘Uncategorized’ Category

Roy & I

March 11, 2017

Roy Austen (1953-2017), a former colleague, died a few days ago on March 5.

A friend recently told me that Roy had been diagnosed with cancer in January, although he had actually been unwell for months before then.

Not long after the diagnosis, Roy set up a GoFundMe page for medical expenses and for the ongoing care of his son, in preparation for the inevitable.

I really did mean to get in contact, but I got busy and Roy died before I did. At least there was still the fund…

Roy’s main line of work and his passion was photography, but that’s not how we got to know one another.

I bought my first Windows (3.1) PC from his family business, KM Computers.

Then, awhile later, he offered me a job and became my boss…

By the end of 1995 I was in search of my next job after 5 years at the University of Tasmania (UTAS) in Launceston as a computer systems officer then a junior academic in the Department of Applied Computing. A lot of university contracts weren’t being renewed around that time.

Luckily for me, Roy had recently started Vision Internet, one of a small but growing number of competing Internet Service Providers (ISPs) in Tasmania. It was a small business arising from KM Computers at a time when Internet access was still dial-up, ISDN/ISDL was the fastest you could hope for (128 Kbps), but most people just had a dial-up modem, giving up to around 56 Kbps, less in practice. Vision Internet started in Launceston but quickly added points of presence in other parts of the state, including an Internet Cafe.

In 1995 while still at UTAS, I had helped Roy out by writing a basic customer time accounting program in C that read utmp/wtmp logs and generated simple output when someone else had difficulty doing so.

By 1996, Roy needed a programmer and system administrator and I needed a job. Before accepting Roy’s job offer, I was up front with him that I would probably want to do something different after about 18 months. That happened with Karen and I moving to Adelaide in 1997 where I spent 10 years with Motorola. That move was more difficult than I expected, and at least as hard as Karen knew it would be. In the end, it was a good move.

Ironically, UTAS asked me to come back for some occasional part-time tutoring soon after I started working for Roy, which may have been less economical than if they’d just renewed my contract!

Vision Internet was good while it lasted. To be honest, for the first few months, I couldn’t believe I was being paid to write C  (and Perl) code, something I enjoyed doing anyway. 🙂

The compact machine room doubled as my office for the first year or so before we moved down the road to a more spacious building; not as cushy as my office at UTAS. I actually didn’t mind the machine room too much. A terminal with function key accessible “virtual consoles”, the vi editor, command-line shell, a C compiler, and a Perl interpreter kept me pretty happy. Roy was fine with me working from home occasionally as time went by too. He expected me to keep things rolling and solve problems as quickly as possible, but he was good to me and we got along pretty well.

There were only about half a dozen people working at Vision Internet, fewer early on. Everyone pitched in. Roy and I didn’t always see eye to eye though. For example, at one point we disagreed about who should have super-user privileges; more than I would have liked for a brief time. 🙂

I experienced a number of things during my time with Roy at Vision Internet and learned lessons from some:

  • Early mobile phones were fairly bulky. 🙂 Roy gave me my first mobile before I started in the job. Of course, this meant he could contact me whenever. He didn’t abuse that though. A former UTAS colleague took one look at the phone hanging off my belt and declared amusingly: “wanker phone”. 🙂 Even worse when a larger battery was added! Still, I appreciated Roy giving me my first mobile.
  • You can’t always spend time doing what you want in a job, even one you mostly like, unless you’re very lucky. I guess I already knew that from being a nurse in the 80s. I had no real interest in sysadmin tasks like applying security patches to BSD Unix kernels, maintaining backups, chasing hackers, worrying about what dodgy things people might be doing with our systems or customer sales, credit card transactions, help desk (shades of The IT Crowd: “is your modem plugged in?”). I mostly wanted to design, code, and test software. Still do. That’s largely why I told Roy I thought I’d want to move on after about 18 months. Having said that, a fair amount of my time was spent writing software in the form of a suite of customer time usage programs, each prefixed with tu, written in C and Perl. We also eventually sold tu to another local ISP.
  • The practical difference between code that uses a search-based processing algorithm over a linear data structure that runs in polynomial vs logarithmic time – O(n^2) vs O(n log n). This matters a lot as the number of customer records (n) increases when your task is to write a program that processes customer time usage once per day and obviously before the next day starts. To simplify: given a processing time of a second per customer, n≈300 can mean the difference between a run that takes a day instead of an hour. You can make incremental changes to the processing time per customer (t), but eventually you’ll hit a point where n is too large, e.g. when n=1000 and t is 0.1 seconds. Anyway, I don’t recall what our n and t were, but we hit such a limit with a tu program. When I realised what was going on and fixed it, Roy was delighted and relieved. I was pretty happy too and thanked my computer science education, in particular, the discipline of computational complexity.

Before I left to go work at Motorola, I made sure Roy wasn’t going to be left without someone in my role. This gave one of my former UTAS students (Craig Madden) the opportunity he needed to break into the industry; it turned out well for Roy and Vision too.

At the height of Vision Internet, I remember occasional staff gatherings at Roy’s. He was a good host and I think he mostly enjoyed that period, despite the worry that must’ve accompanied running a business. He was generally optimistic and trusted those he employed. He had his moments, like the rest of us, when he was unhappy or angry, but mostly, he was a good guy to be around.

If I could do so, I’d tell him this:

Roy, I’m really sorry you’re gone and that I didn’t make the time to get in contact. In recent years, I should have told you how much I appreciated the opportunity you gave me a long time ago. Upon reflection, after time spent together at Vision and elsewhere, I think we would have used the word “friend” (now distorted by social media) to describe our relationship, not just “colleague”, even if we didn’t say so. I should have told you that too.

ASASSN-16ma update

November 9, 2016

As mentioned in yesterday’s updated post (with finder chart), conditions last night were less than ideal, but when the clouds cleared enough, I estimated the nova’s magnitude at 6.1.

asassn-16manov10

 

ASASSN-16ma: easy binocular object

November 8, 2016

Last night’s observation of ASASSN-16ma was with 7×50 binoculars rather than my Meade LX-90 8″ SCT. The nova is now on the verge of naked eye visibility!

asassn-16ma

I estimated the nova at magnitude 5.5 last night with one before mine at 5.4 and two subsequent observations of 5.8 and another at 5.9. Mine are highlighted in purple as usual.

Here’s the section of Sagittarius of interest as it currently appears from Adelaide, low in the south-western sky at around 9pm:

sgr

The nova is just west of the circled star HIP 90012, the 6.2 (labeled 62) magnitude star near the middle of this AAVSO finder chart:

x16923acn

If you rotate this chart 90 degrees to the right, it will have roughly the same orientation as the Stellarium sky scene.

Alnasl is the star labeled 30 (magnitude 3.0) at bottom right of the finder chart. Kaus Media corresponds to the label 27 and Kaus Borealis with the star labeled 28. Kaus Australis and Φ Sagittarii do not appear on the finder chart, but would be off to the left of the unrotated chart.

As I write this, the sky here in Adelaide is quite overcast, so there may be no observation from me tonight.

 

TCP J18102829-2729590’s undulations

October 29, 2016

My visual estimate of nova TCP J18102829-2729590 last night was magnitude 8.0 using my trusty Meade LX-90 at 82x magnification. In my light-polluted corner of suburban Adelaide, 7×50 binoculars just aren’t good enough for this.

The third observation from right, three days ago, showed an apparent rapid increase in brightness. For me, one of the attractions of novae is their less than predictable nature.

Looking at the light curve today, my observations look a bit like (purple) buoys bobbing up and down on the surface of an undulating ocean.

tcp-j18102829-2729590-lc-oct-29

Maybe I’m spending too much time looking at novae at the moment. My wife would probably agree with you, even though she’s very understanding. 🙂

ASASSN-16ma = PNV J18205200-282210

October 29, 2016

ASASSN-16ma, the nova candidate in Sagittarius, has been designated PNV J18205200-282210 by IAU CBAT as per today’s AAVSO alert notice.

I made another visual estimate of the nova again last night at magnitude 10.3.

asassn-16ktlcsep29

Nova in Lupus!

September 26, 2016

ASASSN-16kt was discovered in the constellation of Lupus on September 24 by the All-Sky Automated Survey for SuperNovae with data from a 14″ telescope in Chile.

The discovery magnitude was 9.1 with nothing greater than magnitude 17.5 previously known at that location.

I made a visual estimate of the nova at magnitude 6.7 tonight (September 26) from suburban Adelaide with 7×50 binoculars. At the time of writing, only 8 observations by 6 observers had been submitted to the AAVSO International Database including three Australian amateurs: Terry Bohlsen, Rod Stubbings and myself (highlighted at right), two Argentinians (Gustavo Ballan and the near-omniscient Sebastian Otero) and one Brazillian (Alexandre Amorim).

asassn-16ktobssep26lcg

Other than photometry (visual or image based), amateurs are increasingly taking the spectra of bright novae, and ASASSN-16kt is no exception, with Terry Bohlsen (New South Wales) taking an early spectrum soon after discovery.

These Stellarium screenshots show the location of the nova in Lupus as the south-west sky appeared at around 8pm tonight from Adelaide (wide and narrow field):

Lupus constellation borders.png

lupus-zoomed

The AAVSO finder chart (7.5 degrees) is shown below in a similar orientation:

x16657jv

I was interested to see a request from a researcher, Laura Chomiuk, for high-speed photometry of the nova to:

…to test a recent theoretical prediction of Ken Shen’s: that novae should show fast periodic oscillations in their optical light curves, if gravity waves help expel the envelope.

Time will tell whether the nova has peaked short of naked eye visibility. I hope to make another observation tomorrow night but the forecast does not look favourable for at least a couple of days thereafter.

At least this nova waited for the cloud-dominated winter we’ve just had to pass by.

300 variable star observations

September 8, 2016

I recently passed 300 variable star observations, having started in 2010.

301 obs

That’s a tiny number compared with prolific Australian visual observers like Rod Stubbings or those doing CCD photometry (e.g. of eclipsing binary variable stars) who quickly reach the thousands, such as fellow ASSA member Robert Jenkins or AAVSO’s Mike Simonsen.

Still, I’m pleased with my few hundred plodding individual observations of 16 variable stars, namely:

  • pulsating variables: R Car, l Car, W Sgr, X Sgr, L2 Pup, eta Aql, alf Ori
  • novae: T Pyx, V1369 Cen, V339 Del, Nova Sgr 2015 No. 2
  • eclipsing binaries: zet Phe, BL Tel, V Pup, eps Aur
  • the massive, once naked eye visible, unstable star: eta Car

Most of these are visual observations, and most of those were with 7×50 binoculars:

 

264 visual obs

I started making DSLR photometry observations in early 2015 after taking Mark Blackford’s first AAVSO CHOICE course on the subject:

36 DSLR obs

While visual estimates are quick and convenient in a time-poor life, photometry requires some effort from imaging through to processing and analysis, but the additional accuracy and error characterisation are satisfying, as is the ability to capture multiple bands in a single image, Johnson V and B primarily.

My last DSLR submission was in April. I’m looking forward to some nicer weather so I can get out and do more soon, in addition to the visual estimates I sneak in between the clouds.

Another Gravitational Wave detection

June 16, 2016

Another gravitational wave detection by LIGO has been announced!

See https://www.ligo.caltech.edu/news/ligo20160615

The June 15 announcement page points out that while the signal was weaker than the first detection due to the black hole masses being smaller (14 and 8 solar masses vs 36 and 29):

…when these lighter black holes merged, their signal shifted into higher frequencies bringing it into LIGO’s sensitive band earlier in the merger than we observed in the September event. This allowed us to observe more orbits than the first detection–some 27 orbits over about one second (this compares with just two tenths of a second of observation in the first detection). Combined, these two factors (smaller masses and more observed orbits) were the keys to enabling LIGO to detect a weaker signal. They also allowed us to make more precise comparisons with General Relativity. Spoiler: the signal agrees, again, perfectly with Einstein’s theory.

The news release continues:

Our next observing interval – Observing Run #2, or “O2” – will start in the Fall of 2016. With improved sensitivity, we expect to see more black hole coalescences, and possibly detect gravitational waves from other sources, like binary neutron-star mergers. We are also looking forward to the Virgo detector joining us later in the O2 run. Virgo will be enormously helpful in locating sources on the sky, collapsing that ring down to a patch, but also helping us understand the sources of gravitational waves.

Gravitational Wave astronomy does seem to have arrived!

 

Another early morning rainbow

February 23, 2016

About to ride to the bus station this morning; greeted by another nice rainbow:

 

Brought to us by the laws of physics. No pot of gold evident. Pity.

My first DSLR photometry observation

February 3, 2015

After more than 5 months of gearing up to do DSLR photometry and two AAVSO CHOICE courses later, I submitted my first DSLR photometry observation yesterday: R Car, magnitude 5.054 with an error of 0.025.

First Submission

With a visual observation, the best I could have said that it was magnitude 5.1 with an error of a tenth of a magnitude. With DSLR photometry I can get down to a hundredth of a magnitude. A CCD could do better (a thousandth) but for ten times the cost, or more.

Yet another step in the evolution of my hobby. Thanks to Mark Blackford for sharing his considerable experience.