Nova Cygni 2014

Nova Cygni 2014 has been behaving in an interesting way; overlayed on the general rise to max and decrease after max, are variations with an amplitude big enough to be prominent in visual observations.

Observations of Nova Cyg 2014 from the AAVSO archive


I have observed the nova a number of times, using the 90 mm Maksutov-Cassegrain. It is easy to find, with star hopping-friendly asterisms nearby. It is the third nova I’ve observed recently, the other two being Nova Cep 2014 and Nova Del 2013, also known as V0339 Del.

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Guerilla astronomy

The weather forecast for the coming days shows some chances of partly clear skies at night, but the odds are not very good.

As usual.

My 20 cm Newton is kind of bulky, and not the type of instrument one quickly sets up to observe through gaps in the clouds (I don’t have it permanently mounted, have to carry it outside for observing). No, for nights such as tonight, I rather prefer my 15×70 binoculars and my 90mm Maksutov-Cassegrain, small instruments that are easily and quickly set up in my backyard.

90mm f/13.9 Maksutov with 8x50 finder. The telescope has a quite decent limiting magnitude of 12.4 with my 6.7 mm Explore Scientific eyepiece, even when observing from my urban location.


In a number of minutes, one is set up to observe. The pair of 15×70 binoculars is a fast instrument, and the 90mm Maksutov-Cassegrain reaches 12, even 12.4 on a good night (from my urban location). I use the same 8×50 finder with the Mak and with the 20 cm Newton, which speeds up starhopping. It is mounted on a Triton alt-az mount which is sufficiently stable, even at 185x.

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Lightcurve: T Cep

First in the series of posts on lightcurves is T Cep, which has become one of my favorite variables. It is circumpolar, which is always a nice thing – no season gaps in the light curve. Also, it clears the neighboring five storey house during winter and spring, which means that I can follow it all year around from my backyard, without moving about. 15×70 suffice most of the time, but I need a telescope to pick it up near minimum.

I’ve followed T Cep since late October 2011, through three maxima and two minima. The minima look more or less the same, while the maxima have quite different forms:

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Lightcurves

I’ve been observing variables since late October 2011 (plus a stint as a variable observer as a student in the late 1980′s), so for some variables I have now collected so many observations that I can plot light curves spanning reasonably long periods of time. I thought I’d begin an irregular series of posts of such light curves here on the blog.

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Nova Delphini 2013

Koichi Itagaki has discovered a bright nova in Delphinus. After spectroscopic confirmation, it got the official designation Nova Delphini 2013.

At first, the sky over Lund was cloudy. I waited and waited, but at about 02 local time (00 UT) I gave up and went to bed. However, some 45 minutes or so later I awoke and decided to leave bed and was greeted with a clear sky!

The nova was easy to find and I estimated its brightness to be 6.0 at August 15, 00.50 UT using 6×30 and 15×70 binoculars. The sequence used was an AAVSO chart, with convenient comparison stars at 5.7 and 6.2.

After that, the nova appears to have brightened somewhat:

Looking forward to following this bright nova!

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Bright supernova

I observed SN 2013DY tonight: July 20.928 UT, 13.1.

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A new Algol variable

H. Bengtsson, P. Hallsten, A. Hemlin, G. Holmberg, T. Karlsson, R. Wahlström, T. Wikander, “V2331 Cygni is an Algol Variable With Deep Eclipses”, has just been published in JAAVSO. Read it here.

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Variable star observers meet in Gothenburg

I spent last weekend attending the 2013 spring meeting of SAAF/V, the variable star section of SAAF, the Swedish association of amateur astronomers.

First, variable star observer extraordinaire Hans Bengtsson received SAAF’s Amateur Astronomy Award for his longtime work in variable stars and other parts of amateur astronomy. While announced at the Värmland Star Party, Hans now received the award diploma from SAAF’s Jan Persson. He is truly a worthy receiver of the award, not only for his contributions to the field from the late 1960′s and onwards, but also for his continuing work with the variable star section. It is such a boon for the variable star group to have access to Hans’ deep knowledge of variable stars.

There were several presentations and discussions focusing on digital technologies. Robert Wahlström presented his more or less automated setup using, among other things, ACP scheduler, and we discussed and compared our experiences using remote telescope facilities such as iTelescope, Sierra Stars, Bradford Robotic Telescope and AAVSOnet.

Tomas Wikander was appointed new leader of SAAF/V. Furthermore, there were discussions of new discoveries and ongoing observing programmes. Tomas Wikander presented his recent discoveries of three new short-period variables, one of them a rare high amplitude delta Scuti star. We also discussed the current status of our programme to observe 50 obscure mira variables, and V2331 Cygni, discovered last autumn to be an eclipsing variable with deep minima. Plans for future programmes were drawn up, as was SVO, our magnificent database run by Thomas Karlsson.

Hosted by Slottsskogsobservatoriet, the public observatory at Gothenburg, the meeting was a great success. I am already looking forward to the next meeting.

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Värmland Star Party

I spent last weekend in lovely Lysvik, where the annual Värmland Star Party takes place under a dark sky. Everything was great! Got to meet interesting people, hear interesting talks – not the least Johan Warell’s on comets and how to observe them – and the sky was clear for one and a half nights out of two. What’s more, there were several variable star observers there to talk shop with.

SAAF, the Swedish Association of Amateur Astronomers held its annual meeting on Saturday. SAAF also presented two awards: the Margareta Westlund award went to Thomas Karlsson for his work on variables (his observations of the eta Aurigae eclipse, his development of the SVO database, and his studies of O-C statistics of miras), and the Amateur Astronomy Award went to Hans Bengtsson for his longtime and ongoing enthusiastic efforts to spread knowledge about variable stars and other celestial phenomena.

Johan Warell, right, presents the Margareta Westlund award to Thomas Karlsson


During the observing sessions, when I was not recuperating from the -14 degrees Centigrade by visiting the nearby meeting rooms to drink coffee and eat hot dogs while chatting away with fellow amateurs who temporarily escaped the cold, I mostly observed together with Tomas Wikander. Tomas had brought his 12 inch SkyWatcher Flextube Dobsonian and he kindly let me join in, we had a great time with a mixed diet of variables and deep sky objects. The sky was very good, almost a magnitude better limiting magnitude than here in Lund. NGC 4565 was a wonderful sight, as was M51. I noted at least two personal firsts: the zodiacal light and the Horsehead nebula, the latter helped along with Johan Kärnfelt’s H-beta filter.

Tomas Wikander observes the sun through one of the many h-alpha telescopes set up at Värmland Star Party during the day


The Värmland Star Party, deep in the forests of Värmland by the lake Fryken, has been run for more than twenty years by a group of amateurs known in Sweden for their aperture fever, is highly recommended!

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Solar observing

I used to observe sunspots with my 60 mm refractor during the 1980s and reported the observations to the solar section of SAAF, the Swedish amateur astronomical association.

Recently, my curiosity about what the sun is up to grew and I started counting sunspots again in January. February was awful, weatherwise, otherwise its great to be observing sunspots again. I report my observations to SIDC, the international sunspot data centre, as well as to SVO, SAAF’s variable star database, which also tracks solar activity.

Not much of activity for a maximum year, but still it is interesting to follow the sun’s activity from day to day.

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