Variable Star Observing Down Under

Published in the AAVSO Newsletter – April 2013

Rod Stubbings (SRX)—Variable Star Observing Down Under

Kevin Paxson (PKV)—Centerville, Ohio
rodstubbings-21
Rod Stubbings (SRX) is 57 years old and he lives about 140 km (84 miles) east of Melbourne, Australia, in the state of Victoria, with his wife of 32 years, Cheryl. He has four daughters (two of whom still live at home). Rod has been a self-employed licensed plumber now for over 38 years. He
is also one of the most prolific visual variable star observers in the southern hemisphere and leading cataclysmic variable star observers in the world. As of February 2013, Rod has a total of 214,188 visual observations in the AAVSO International Database. Rod is well published and either has authored or coauthored 67 papers from 1995 to present, according to a recent search of the NASA ADS system.

Rod’s interest in astronomy started in 1986 while reading a magazine in
which he noticed a 60mm telescope for sale to observe Saturn and Jupiter. “I
ordered the telescope and once it arrived I headed outside to find these planets.
I could barely focus on the stars let alone find anything, but eventually I
spotted one and went in to tell my family. Embarrassingly, I had to tell them
later that it was not a planet after all, but some dust on the lens! I later read
up on astronomy and bought a book called Stargazing—Astronomy Without a
Telescope by Patrick Moore. Over the next few years, I slowly began to learn
the names of the stars, the constellations, well-known objects, and where to
find those planets.”

Rod was introduced to variable stars by attending a meeting of the Latrobe
Valley Astronomical Society. “At that meeting, Peter Nelson was giving a talk
on variable stars and how observations can contribute to science. I decided
to give it a go. Peter had been trying for years to get people interested in
variable stars and I have been his only pupil. I read the book The Observations
of Variable Stars from the Royal Astronomical Society of New Zealand
(RASNZ) and made my first visual observation of the naked-eye Cepheid
variable star l Carinae in May 1993. I made 10 observations during my first
month of observing and this number has steadily increased to over 1400
observations per month, often with 30 to 50 dwarf novae outbursts per month.”

Rod became a member of the RASNZ in May 1993 and he soon gravitated
to observing cataclysmic variables. “Over the next few years, I was detecting
numerous CV outbursts, which were kept in my log book and sent to RASNZ
every month. I came across the VSNET alert mailing lists in 1997, which
reported the outbursts of CV stars. I also decided to send every detected
outburst to VSNET, which was often a few per night! A few weeks later I
received an email from Frank Bateson that said, ‘You may receive e-mail
messages resulting from your alert messages requesting additional data. If
you do I suggest you tell the enquirer to contact me so they can obtain our
complete record. I have already received such requests from those who know
you are one of our observers, but others may not know of this connection.’”

Two months later another email came from Frank Bateson: “I returned at the end
of last week from the meeting in Switzerland. You will be pleased to know that
your alert notices are being well regarded worldwide. Keep up the good work.”
“In July 1997, I received an email from Janet Mattei regarding my alert
notices on VSNET. ‘If you would be interested in sending your observations
directly to the AAVSO, in addition to the other networks to which you send
them, we would very much like to include your observations in the AAVSO
News Flashes.’ Thus my association with the AAVSO began. I have been a
member of the AAVSO now for the past two years.”

Rod started observing with simple equipment and it has been a progression
over time. “It all started from naked-eye to binoculars, a 60mm refractor,
150mm, 250mm, 320mm, and 400mm Newtonian reflecting telescopes. Each
aperture gain was used to study fainter variable stars. Next on the list is a 22-
inch!”

Rod’s Tetoora Road Observatory is “situated in the foot hills of the Strzelecki
Ranges in a rural area at 260 meters (806 feet) above sea level. I have an
unobstructed 360 degree view. I can see snow in the mountain ranges north
and water views in the distance from Westernport Bay (also called Western
Port Bay) in the direction of Melbourne. All my variable star fields are found
from memory, but I do grab a chart on certain outbursts to double check,
especially when they are important or rare.

“I have a reasonably dark site being out in the country. I have sky glow from
towns 20 km (12 miles) away and city glow 140 km (84 miles) away low
along the horizon. I have no trouble seeing magnitude 15.4 on any night, even
if some haze is present. On better nights, I get down to magnitude 16.0 to 16.6
quite often and magnitude 17.0 stars can be seen on very good nights when I
boost up the magnification.”

Rod does not keep clear night statistics. “My total number of observations per
year gives me a better indication of clear nights so over 10,000 observations
is a reasonable year of clear nights. I always aim for a minimum of 100 to 150
observations a night and if I observe all night over 200.”

Rod’s main instrument is a Meade DS-16 on an equatorial mount, which is
situated in a homebuilt domed observatory. “When I first used my Meade DS-
16, I lost half of my variable star fields because I could not get to the eyepiece
because it was in a fixed position. This was very quickly remedied by adding
a pair of rotating rings so the whole tube could rotate and hence get to the
eyepiece at my eye level.”

Rod “star hops” to find his targets. “Through the finder I see more patterns
and angles leading directly to my variable star fields all from memory. In
most cases, I have a 9th-magnitude star in or close to the variable that I can
see through the finder. So after one aim of the finder I’m looking through the
eyepiece at the variable star field within a few seconds.

“I only have two eyepieces, a 9mm Nagler (200× and 23.4′ FOV) and a 6mm
Ethos (300× and 19.8′ FOV). The 6mm Ethos is my main eyepiece and the
9mm is used when conditions are a bit off.”

Rod has a regular nightly routine. “As soon as it’s dark I am outside observing.
I start off in the west to catch stars before they set and then I go to the stars I
feel are due for an outburst. Then, I follow all the active stars, as I like to
complete their rise and fall cycle, and later I cover the entire sky and get
acquainted with my list of variables rising in the east. After finishing, I go
inside to report new outbursts and current activity to CVNet and VSNet, and
that leaves me with around 4 hours sleep before I get up for work.

“I don’t really have any favorite variable stars, I just like them all. A few years
ago Albert Jones contacted me and asked if I could keep observing some
of his symbiotic and Wolf Rayet stars. He was worried about the long term
light curve of these stars so I added them to my list. Albert also gave me the
contacts of where to send these observations.

“I’m also starting to enjoy observing WW Cet. After years of observations, I
knew something was different at the start of 2010 when WW Cet was stuck on
12.0 magnitude. It still hasn’t had a bright outburst in three years now and it
appears to be a Z Cam star. I also observe the symbiotic stars AE Ara and AR
Pav and have been getting some nice light curves of their eclipses. I also have
added under-observed Miras to see what I can find about their behavior. One
in particular is DM CMa, which was classified as a Mira, but my observations
show it to be a UG star with short and long outbursts.”

Over the years Rod has “paid close attention to all the known CVs and
searched the catalogues for all unobserved CVs and studied their outburst
patterns, rise and fall durations.” This has led to many first-ever visual
outburst detections or outbursts which have revealed the true nature and
reclassification of these stars.

Here is a listing:
WZ Sge outbursts: SV Ari, GR Ori, GW Lib, CG CMa, and VX For.
New CV’s or confirmed SU UMa stars: V591 Cen, V1089 Sgr, FL TrA, V359
Cen, V422 Ara, DT Oct, V383 Vel, CC Scl, LY Hya, V728 CrA, EG Aqr, EX
Hya (detection of this known IP in 1998 led to the first-ever RXTE satellite
observations), HV Vir (the fifth outburst detection of this known CV), RU Hor,
RX Cha, RZ Leo, V1047 Aql, V485 Cen, V877 Ara, XZ Eri, AD Men, AX Cap,
BC Dor, KK Tel, V551 Sgr, V699 Oph, AB Hor, EP Car, MM Sco, FQ Mon,
V2051 Oph, V344 Pav, TU Crt, EF Eri (this known IP switched off nine years
before detection), and SDSS J163722.21-001957.1.
Black hole binary: V4641 Sgr: (this 8th-magnitude detection diverted the RXTE
satellite and radio telescopes around the world to observe this outburst event).
New RR Lyrae stars: U PsA (visual observations showed a period of 0.54187 day
and a new RRAB Lyrae star) and SW Crt (visual observations showed a period of
0.493164 day and a new RRAB Lyrae star).

While Rod is not credited with discovery of the 2011 outburst of T Pyx, he did
catch some interesting pre-outburst behavior. “On April 5, nine days before
the outburst, I found T Pyx was brighter than normal at magnitude 14.5. It
varied between magnitude 14.4 and 14.7 that night and I decided not to report
as it was just brighter than normal state. The following night, on April 6, T
Pyx was still above normal brightness at 14.7, April 7 14.8, and April 10 at
magnitude 15.0. Mike Linnolt caught T Pyx at magnitude 13.0 on April 14,
2011. I later found out that I had observed a unique brightening before the
major outburst. This has only been the fourth known rise or dip closely spaced
before a nova eruption.”

Rod has participated in nearly two dozen professional/amateur collaborations
from 1995 to present. “Collaborations are what make variable star observing
so rewarding. Corresponding with professionals, getting requests, and
exchanging emails about observing programs knowing your observations
are triggering satellite observations.” Some of these collaborations and
campaigns were with the AAVSO and the RASNZ, but many were arranged
privately with CV researchers. Most of these have results in publications and
a few are still ongoing.

Of his many publications, Rod’s paper on U PsA stands out in his mind. “In
1996, I read an article on U PsA, which was still an unclassified variable
despite its early designation. The article stated a magnitude range of 12.5 to
<14.0 with possible periods of 117 and 235 days. The advice was to observe
it once a week to determine its nature. I decided to observe U PsA; however,
I had no sequence so I assigned my own. I observed U PsA every night and
I noticed it varied each night. So I stepped it up to observations every few
hours per night and my observations found a period of 0.54187 day. CCD data
confirmed my period.”

Rod received the AAVSO Director’s Award in 2002. “When Janet first
contacted me to tell me I had received the Directors Award and that she
wanted me to attend the meeting in Hawaii, I felt honored. I am a pretty quiet
person—I had never been on a plane or around Australia let alone overseas
and I was not sure about attending the meeting. I wasn’t going to go, but Janet
being Janet persuaded me. I was so glad I went because the AAVSO staff was
fantastic and Janet was a real people’s person. No one knew who I was other
than my observer code, and when Janet introduced me to Gamze Menali she
said, “Gamze, I would like to introduce you to someone, this is SRX.”

When not observing variable stars, Rod enjoys gardening, tending to his fiveacre
hobby farm and raising pedigree Black Faced Dorper Sheep. He also
likes building and construction. “I have built my entire house from the ground
up which included all facets of plumbing (of course), timber work, concreting,
plastering, painting, tiling, and wiring.”

Despite the advancement of CCD technology and numerous all sky surveys,
Rod sees himself as a visual observer for now and into the future. “I see
variable star observing in the future to be more and more automated with
CCD surveys.” However, “I believe you cannot overvalue the contribution
of visual observing compared to CCD imaging. A CCD camera cannot make
instant judgments on a star’s state, or call upon experience the way a visual
observer can when directly viewing the stars.

“At present I believe visual observing can still complement the surveys with
selected targets. An example of this was with my observations of SW Crt. I
observed SW Crt hourly throughout the night and my observations revealed a
period of 0.493164 day. The survey data were added and the period confirmed.
The survey data [alone] could not [yield] a period because there were too few
data points.

“For me, I prefer to be outside observing hands-on and watching what events
are taking place rather than waking up in the morning to check my images to
see what has happened. There are many targets out there for visual observers
to contribute important observations and make discoveries. You just have to
be selective in what you are observing.

“I’m still as keen as ever and visual variable star observing will never leave
me. I will eventually open my observatory up to the public for monthly
observing. I have school groups occasionally visiting my observatory now, but
I don’t want to slow down on my observing at this stage. I can still improve on
what I’m doing once I retire!”

Rod will be celebrating 20 years of variable star observing next month and
he does not appear to be slowing down any time soon. For more information
about Rod, his observatory, discoveries, and publications, check out his web
site at: https://rodstubbingsobservatory.wordpress.com/. Keep up the great
work, Rod!

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