NGC 1448 with SN 2001el (image kindly provided by Ted Dobosz)
In this section we will introduce some stories related to the world of astronomy. If you have an interesting experience you would like to share with us, feel free to contact us!
Sept. 2001. This month we present the fascinating experience of Berto Monard, South Africa, who discovered a bright supernova, SN 2001el. Thanks, Berto, for making us part of this adventure!
-----------------
"It
was Sunday 16 September 2001. It had been raining two days before and the clouds
still struggled to dissolve despite a strong wind. It was a week now since my
last observations. In the evening, it finally started clearing again and I got
in some observations of cataclysmic variables (CVs) and galaxies from the Grus
and neighbouring groups. The sky, now thoroughly cleaned from haze was pitch
dark with bright and twinkling stars, a typical case of good transparency and
bad seeing. Under such conditions the Milky Way, with Sagittarius around zenith
looks impressive from my rural site, which I estimate a rating of about 3.3 on
the Bortle scale. DSO-ing with a fast 12.5" Newtonian is quite rewarding
then, but that's not what I was after….
The
observations didn't last long. Cloud fragments came over and I had to retire for
the night. Hopefully it would improve again later in the night and I counted on
my regular insomniatic wake-up around 2 am. Observations of the Fornax and
neighbouring galaxy clusters were due, specifically SN 2001du needed to be
checked up. The time came and I waked up around two
o' clock local time, exactly midnight UT. It would be cold outside and I
actually didn't feel like going out, but then I remembered to have never
regretted observations before dawn and there was Bob’s recently discovered SN
2001du. So out I went. Only
hooked-on observers do that...
My
observatory is about 80 m from the house. It is orientated straight East and
overlooks the valley to the North East. Our property lies on a ridge and it's
seldom that there is no breeze. But this time it was barely noticeable. The sky
was open and looked steady. This is what I was hoping for. While walking I
reflected on bad things that had happened in the world. Would my observations
also reveal some unexpected violence? Now was the time of anticipation, the
excitement that keeps the VS observer and SN searcher going.
I
did the usual routine, rolled out my trusted 12.5”f/4.8 Dobsonian, loaded the
turret with the usual set of eyepieces
and got started on some variable stars in the Hydrus region. It was now half past two and
time for the hunt. The
first galaxy I visited was NGC 908, one of my favourites with promising SN
producing characteristics and a good comparison sequence thanks to A Henden.
Next came the galaxies in Eridanus and then more to the South, the Fornax
cluster. The foremost spiral galaxy in Fornax is
NGC 1365. It’s an early spiral (SBb) of large size and about 45 degrees
inclined. Recently they derived a distance of about 17 Mpc (H=75) to it,
somewhat indicative for the cluster as a whole. It’s here that SN 2001du
resided. Its positive observation
and estimate of 15.1V could have possibly be the highlight of my observing
session. After this I did some more galaxies in Fornax and Eridanus.
The
next galaxy group that would follow in logical order, is in Horologium. But I
have the habit of keeping it over for later. It concerns the group with ao the
nearly face-on NGC 1433 and an edge-on spiral galaxy of no particular interest,
NGC 1448. Actually it is not that bad a group, but somehow it was not amongst my
favourite areas… So
up to the South, to NGC 1559, a somewhat isolated late spiral (Scd) which had
been productive in the past. I have often wondered if that 13th
magnitude foreground star had anything to do with that.
The
next group I find quite interesting. It starts off the bright star alfa Dor. NGC
1566 must be one of the better SN producing candidates, a pleasing face-on
middle type (Sbc) spiral galaxy with rich spiral arms. Surprisingly it has a
clean record. Other galaxies in Dorado are the nearby pair of NGC1549 and NGC
1553, and the edge-on NGC 1515. Because
of the pristine conditions I also did the extra bit, NGC 1533 etc..
Then
back to Horologium. Starting from alfa and delta Hor, one gets to NGC 1512,
which has some convenient faint neighbouring stars, a clear view of them
reassuring good observing conditions. But
again there was no SN. Then a side trip to the warped NGC 1487. Next target, NGC
1448… Like NGC
134 it has nearby stars on both sides of its nucleus: in its case there is one
quite bright, but the other only clearly visible under good conditions. Those
conditions and both stars were present, so was a third star in between them….
Since
my move to my new site I have often had the need to consult the images,
especially under good observing conditions. Stars that were completely out of
reach from my previous suburban location, suddenly popped up. Galaxy
neighbourhoods had to be re-studied. However this new star very close to the
nucleus, I should have picked up on previous occasions. I was about to doubt my
memory, but a look at the DSS image didn’t show anything there. On later
inspection there was a slight condensation, probably a star forming region. It
would make sense that SNe type II would occur there.
I
didn’t need much time to realize what I was seeing. I was excited, possibly
not more than on previous occasions, when foreground stars imposted as
supernovae or planetoids as novae. NGC 1448 is far away for the MW and the
ecliptic, so the new star was unlikely to be a planetoid or nova. I would check
this up anyway, next morning. But
deep inside I knew this one was real. I made an estimate of magnitude 14.6V for
the brightness using a preliminary sequence. An improved sequence would change
that later to 14.5V. It
would be quite sometime before I would notify, so I carried on observing the
remaining parts of the program, including some more CVs that rose in the East. I
made another observation of NGC 1448 and closed up just before dawn. It had been
a good observing session.
Soon
I would go to work. That’s where the e-mail would be sent from. I knew I had
seen and discovered a new
supernova. But was I the first to have seen it? ‘Probably not’ was my
conclusion after hours of considerations. I hadn’t seen e-mails since Friday.
A lot could have happened since. Probably there were e-mails waiting in my
e-box, requesting confirmation or follow up of a new supernova or a suspect in
NGC 1448. Nobody would believe my independent discovery. And I had decided in
that case not to forward any claims or chase any endorsement, but to hope for
better luck next time.
That
were my thoughts when I entered my office. I was prepared for the eventuality.
Still, I gave myself some chance for glory, but less than 50%.
In
the mean time Murphy had done his round in our workplace. The e-mail and
internet systems were not accessible. After several hours, my (hyper)tension was
growing, when there was some response when trying to log in. The posting list
flashed on the screen for a few seconds, then it all looped up again. It took
another hour before there was a steady and useable display of the messages, and
there were quite a number of them. I started reading titles….After about 400
of them it was clear, nothing about NGC 1448. I couldn’t believe it. But then
I also noticed the lack of postings from the Australian region. That’s where I
would expect a notification from.
To
make the story short, the internet access locked up again. Sometime later it was
working again but nothing from Australia. I wrote an observation notification,
and sent it to SN observers for confirmation. After a few minutes, the
connection packed up again and it
was obvious that my postings hadn’t gone through. I was in distress, as one
ought to be. Later on in the afternoon, the connection was somewhat
re-established, but no reply came back that day…
The
clear weather had gone but I was determined to make a follow up observation the
next night. Around local midnight I started to patiently observe weather
proceedings with the telescope in readiness. There were some openings in the
clouds but the air was heavy and moist. It took the best of an hour before I
could catch glimpses of my SN suspect, right at the observing limit. Some more
time at the telescope finally revealed some clearer appearances and I was able
to estimate it at 14.3V, 0.2 magnitude brighter than the discovery magnitude 22
hours ago. The SN, if it were one, had brightened. It was important that the
others would know it as well. What if the clouds had persisted and my patience
had been less?
Now
I was very anxious to get at work and read the e-mails. In the mean time the
internet technicians had sorted out most of the problems but the internet access
was slow. They also mentioned a virus. However, I got to read the e-mails. And
there were replies from Australian SN searchers. Nobody had seen anything yet,
the weather had been bad but they would like to confirm. I started rating my
chances to over 80%… The next day would eventually bring more certainty.
In
one of the e-mails from Japan Dr H Yamaoka urged me to send a notification with
my observing and observation particulars to CBAT, based on my own confirmation
of the SN suspect. A bit hesitantly I did so and made also reference to
confirmation reports to come. That e-mail contained the most important
information of the find, including all observations up to then. It was a
blessing that I did send it, as confirmation reports arrived during the night,
some requesting to send additional info to CBAT.
The
discovery had been confirmed by Greg Bock and A Wassilieff despite the terrible
weather conditions they had had during the early part of the night. Their
observations also showed a further brightening of the SN suspect. Possibly there
were more confirmation reports as I got e-mails from Chili and other places.
Those messages however were empty, a consequence of the state of our network.
But I was very pleased with the confirmations that had come through.
But
then I was also very distressed because of what had happened on our plot during
the previous day. Our house was broken into and plundered. There was a lot
missing and not much we could do about it than to phone the police and go
through their usual procedures. The
insurance Co had refused at the time to give cover unless certain (extreme)
conditions and precautions were met. I didn’t think there would be any need
for insurance if those conditions were fulfilled. We knew we were taking a risk,
not a wise decision as it turned out. Fortunately,
all observing equipment in the observatory was still there and intact. Possibly
my dogs had kept them from moving to that part of the property.
Clouds
intensified that day and no observation would be possible for the next nights.
Thursday morning, I finally received news of the IAUC announcement of my
supernova, SN 2001el.
Well
done, Berto, I told myself, and so did many others. It had been a long wait.
I
am very thankful to those observers and sympathisers that went out of their way
to help confirming this nearby SN for which at this stage (22/09/2001) no type
had been communicated yet. My observation of this morning showed a further
brightening of SN 2001el: 13.3V. Possibly it is a type Ia.
Special
thanks to Alex, Brian, Bob, Greg, Hitoshi, Nick, Peter, Robin, and Taichi.
My
discovery of SN 2001el in NGC 1448 (Bob Evans found there SN 1983S) is now the
second one from South African soil! The first one was discovered by Jack Bennett.
It was SN 1968L in M83. He did so not so far from here, in a Pretoria suburb
under skies that were still dark then. He used a 5” elbow refractor, exactly
the same as my trusted apogee 20x120…
I
intend to find some more SNe in the near future.
Berto Monard / 22 September 2001
Plot 39 / Bronberg Observatory / South Africa
Back to the story of the month
