Celestial Sphere Updated! And some changes to observing programs

10x50 binoculars

Hello Everyone!

As you might notice, Celestial Sphere looks different, and it is true, Celestial Sphere has got a facelift and it has been significantly updated!

First of all, the layout has been updated. Besides this, I have also added some new pages and menu items to main menu of this site. I have promoted some pages to top level, promoted pages are: Solar system sketches and Deep sky sketches. New menu items are: Dark sky observing sessions, Variable stars, Eclipses, Transits and also Atmospheric phenomena. These menu items consists mostly of my blog posts related to these categories and something else too!

I have also made some tough decisions and changes in my observing priorities. I have finally been able to choose what I will be observing after finishing my current visual deep sky observing programs. After considering it for a good while, I decided, that I will come back to my visual variable star observing program. And actually I have decided to re-start variable star observing immediately! I’m going to be observing same set of 10 stars that I was observing in Autumn of 2016. I have decided, that I will finish Caldwell-, Hidden treasures-, and Herschel 400 -observing lists, I will fully focus on variable star observing, but I still may sometimes do some visual deep sky observing.

And then there is a thing that I’m already very excited about: in order to be able to finish Caldwell- and Hidden treasures observing lists, I need to travel somewhere to Southern hemisphere to observe all of the southern objects in these lists. And I could have a chance to travel to Australia in October 2018 to observe the southern Caldwell- and Hidden Treasure -objects! And of course I want to see the Magellanic clouds, Southern Milky Way and all other Celestial wonders visible only in the Southern Hemisphere! After this trip, I would have finished Caldwell- and Hidden treasures catalogues. There still would be some southern objects to be observed in Herschel 400 list, but I would observe them sometimes in future.

The trip to Australia will be a dream come true -thing for me, and I’m already looking forward to it very much! But I’m going to write about that a little bit later.

Then about why I decided to switch priorities and observing programs again. This decision is one of the most difficult ones I have had to do in my life, because I so much love both deep sky- and variable star observing! I have been struggling with this decision, but there has been one factor in this decision making process, that has helped me to do the choice.

That factor is the fact, that by observing variable stars I can contribute to science of astronomy and to help astronomers now and in future to study and understand the stars better. By observing variable stars, I’m making a such contribution, that will greatly benefit a much larger group of people and bigger purpose than if I was just observing deep sky object just for (my own) fun. Deep sky observations of course can deliver lots of fun and enjoyment for me and possibly for someone else too, but I have a feeling within myself, that I feel that it is important for me to participate in variable star science by making my own contribution to the science in form of my own observations.

So that’s why I have made this switch in priorities for now. From now on, I’m going to be focusing on my visual variable star observing program, which consists of the same stars, that I was observing in Autumn of 2016. I hope I can stick to this decision, and variable stars will always be my number one form now on. I still of course might occasionally do some deep sky observing too, but only if I have done all variable star observing for the week.

There would be also so much other things I could write about. But I think that’s all for now, keep on observing and clear skies to you!

 

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Plan for variable star observing for season 2016-2017

In my previous post, I made a personal, semi-scientific, qualitative mini-review on my variable star observations during season 2015-2016. In this post, I’m going to present my variable star observing plan for season 2016-2017.

During observing season 2016-2017, Im going to continue observing variable stars visually with 10×50 binoculars. Based on my conclusions I presented in my previous post, I’m going to make some adjustments to my observing program. During season 2016-2017, my observing program is going to be as follows:

  • EU Del
  • U Del
  • W Cyg
  • X Her
  • ST Uma
  • UU Aur
  • W Ori
  • Y Tau
  • X Cnc
  • RS Cnc

When I was choosing the stars to my observing program, I was considering following criterions:

  1. The star has already long history of observations, and that’s why it is worthwhile to try to extend the already long history of visual observations of the star. Such stars are included in LPV program of AAVSO, and especially in LPV Legacy program. I was selecting my stars from these programs, having emphasis on LPV Legacy stars.
  2. The star is included also in the Binocular -program of AAVSO, meaning that according to AAVSO, it makes sense to observe the star with binoculars
  3. The star is ranking high in the Binocular program of BAA.VSS, meaning that according to BAA.VSS, it is a reasonably good idea to carry on observing the star
  4. The star has suitable brightness range for 10×50 binoculars, and that the star can be observed with these binos throughout the entire cycle of the star
  5. The comp stars are reasonably close to the variable itself, so that it can be easily observed with 10×50 binos
  6. I decided to limit my program to only 10 stars, which I fully commit to observe through to whole season

All the stars happen to be semiregulars of type SRB. Some of the stars are known to be intensively red stars, which can be a challenge for observing. But based of my experience of observing a red star (for example UU Aur) during season 2015-2016, I have a reason to believe, that I can perform observing these red stars well enough.

So, after having a small hiatus from vsriable star observing from early February 2016 to June 2016, variable stars are back in my observing program! The hiatus happened because of my life situation was intensively busy, and in the spring of 2016  I was emphasizing visual deep sky observing. But from now on, I’ll be committing to observing these 10 stars and I’m going to have this small variable star observing program as my top priority! I’m going to also observe deep sky objects visually whenever I have time and energy, but these variable stars are going to be my priority number one!

 

 

My variable star observations from season 2015-2016 – a qualitative mini-review

During season 2015-2016, I was observing variable stars visually with 10×50 binoculars. When observing, I was using a tripod mount. I was mostly doing observations under sub-urban, light polluted skies in Ulvila and Turku, Finland. In both places, typical NELM is about 5,5 and SQM about 20,7 at best. During the season, I made 265 visual observations in total.

The stars that I mostly observed were as follows:

  • EU Del
  • U Del
  • R Aql
  • W Cyg
  • g Her
  • X Her
  • mu Cep
  • rho Cas
  • ST Uma
  • Y Cvn
  • UU Aur
  • W Ori

Besides these, I made also some isolated observations of few other stars. Below I’m going to present you my light curves of these 12 stars that I observed the most during this season. These light curves are produced by the Light Curve Generator of AAVSO, and my observations can be seen as blue crosses plotted against the other visual and V observations of these stars from the AAVSO database. Also the 10 day average curves for visual and V observations is presented. The observations are presented on function of Julian date.

EU Del_2015-2016

U Del_2015-2016

R Aql_2015-2016

W Cyg_2015-2016

g Her_2015-2016

X Her_2015-2016

Mu Cep_2015-2016

Rho Cas_2015-2016

ST Uma_2015-2016

Y CVn_2015-2016

UU Aur_2015-2016

W Ori_2015-2016

Some remarks

  1. In most cases, my observations are well in concert with the other visual (and V) observations, and also the brightness trend is consistent with other observations
  2. Some clear errors can be seen here and there though, but the frequence of errors seem to be rather small
  3. When compared with the other observations, my observations tend to lie in most cases in the brighter part of the light curve, especially if the star is bright. Based on this, it seems that I’m a”bright observer”.
  4. Some stars appeared to be difficult for me to observe, especially rho Cas was like this. There is large scatter in my observations from estimation to estimation, although the brightness of the star barely changed during my observation season, altought I started to observe the decrease of brightness of rho Cas correctly in the very end of my observing season
  5. In some cases, I failed to observe that the brightness of the star had actually changed, for example in the case of mu Cep. In the later part of my observing season, I kept on recording similar estimations of mu Cep, altough it had already started to brighten. I only noted that it had got brighter after having a two weeks long break from observing in the very end of my observing season.
  6. Observing the brighter stars like mu Cep, rho Cas and g Her with 10×50 binoculars was challenging because of two reasons: a) the stars were too bright when observed with this kind of instrument, b) because the distance between comp stars and the variable was too long
  7. My practical fainter limit of working is ~7,5 magnitudes. It is difficult to observe stars that are brighter than 4,5 magnitudes.

Conclusions and actions for next observing season

  1. I’m doing pretty well as a visual variable star observer. My observations aren’t  that bad
  2. For the next season, I’m going to drop some too bright stars off my observing program
  3. I’m going to focus only on those stars, that can be observed throughout their entire cycle with 10×50 binos
  4. I’m going to focus on stars, that vary between ~4 to 8 magnitudes
  5. I’m going to focus on stars, which have their comp stars at reasonable distances from the variable

Light curves from observing season 2013-2014

Here are some of the best lightcurves that I was able to obtain during last observing season, 2013-2014. I was observing mostly some brighter Mira stars but also representatives of few other variable types. All observations have been made visually either with 4” refractor or 10” Newton -type reflector. Observations have been mostly made in Turku, Finland, but also in some other locations.

R Cas
R Cas

R Cas is a Mira -star in Cassiopeia. During last season I observed the brightness of the star to reach it’s maximum, little bit less than 6 magnitudes, and then decline back to minimum, about 11 magnitudes.

T Cas 2013-2014
T Cas

T Cas is another Mira -star in Cassiopeia. It has a characteristic double-humped maximum, but I wasn’t able to observe it during this season. Instead, I observed the star getting fainter during Autumn and the reaching it’s minimum in spring 2014.

T Cep
T Cep

T Cep is a Mira -star in Cepheus. It was very fun and rewarding to follow the ascent of it’s brightness, which peaked in 6 magnitudes in late April 2014.

Omi Cet
Omi Cet

Omi Cet, a.k.a Mira, is the prototype of it’s class, the Mira stars. Omi Cet is a bright naked eye -object at it’s maximum, but it have to be observed by means of  a telescope in it’s minimum. I observed this star during the course of it’s descent towards minimum. It reached it’s minimum light around Christmas 2013.

R Cyg
R Cyg

R Cyg is a Mira -star in constellation of Cygnus. I observed this star around it’s maximum from late July to early November 2013. The maximum waa around August-September 2013. This time the maximum was little bir less than 6 magnitudes.

SS Cyg
SS Cyg

SS Cyg is a dwarf nova -type cataclysmic variable, and it is among the brightest of it’s class. When in outburst, the star reaches magnitude 8, and then descents back to minimum light, about 12 magnitudes. During the season 2013-2014, I was able to catch this star in outburst twice.

V339 Del
V339 Del

V339 Del aka Nova Del 2013 was the first nova that I have ever observed in my life! And what a spectacukar nova it was! It was among the 20 brightnest novas ever observed! The nova appeared in the sky around mid August 2013. It reached it’s peak brightness around 16th of August, then it was as bright as 4,8 magnitudes, and it was also visible with naked eye in a dark place! During the course of Autumn 2013, the star was gradually getting fainter, and it also platooed during September 2013. During the platoo-phase, it’s brightness was descending only very slightly. This object was one of the highlights of the season!

R Leo
R Leo

R Leo is a bright Mira -star in Leo. During the season 2013-2014 I observed this star to ascent from it’s minimum to maximum, and then back to minimum. It peaked around December 2013, then it was as bright as 5 magnitudes.

R Tri
R Tri

R Tri is a Mira -star in Triangulum. I was able to witness a maximum of this star, about 6 magnitudes in December 2013.

Z Uma
Z Uma

Z Uma is a semiregular variable in Ursa Major. It has a pleasently large amplitude for it’s type, which makes it easy to observe. I observed the star to reach it’s maximum in January 2014 and the descent back to minimum.

An interacting pair of galaxies in Easter night

Date: 19./20.4.2014
Time: 23:00-02:30
Observing site: Ulvila observatory, Finland
Instrument: C280/2750mm

NELM: 6.0
SQM: 20.80
Darkness of the background sky: 3
Seeing: 3
Transparency: 1
Weather: Clear sky, calm, no Moon, pretty warm

Objects observed: T Cep, R Leo, NGC 5394-5

I travelled to my parent’s place to Ulvila for Easter holiday. Weather was absolutely fantastic during Easter, it was warm and sunny, and during one night I was also able to do some observing in Ulvila observatory! Nights are already quite short, and we don’t get real astronomical darkness here in Southern Finland anymore, but it is still possible to do some observing for couple of weeks before the white nights of summer.

During the night between Holy Saturday and Easter day I went to Ulvila observatory for observing session. First I did some variable star observing: I checked R Leo and T Cep to see, what they are up to! R Leo is near it’s minimum, about 9 magnitudes, whereas T Cep is around it’s maximum, about 5,7 magnitudes. And T Cep is now so bright, that I could see it with naked eye!

After doing the variable star routine observations, I decided to observe an interesting interacting pair of galaxies well visible in springtime in Northern hemisphere. This pair of galaxies was NGC 5395 and 5394 and the duo is located in the constellation of Canes Venatici, The Hunting Dogs!. This pair of galaxies is also known as as Arp 84 in the Arp catalogue of peculiar galaxies. Both of these galaxies are heavily distorted by tidal forces, and I’m sure they offer fascinating views for bigger telescopes!

NGC 5394-5 aka Arp 84. Photo: Adam Block/Mount Lemmon SkyCenter/University of Arizona
NGC 5394-5 aka Arp 84. Photo: Adam Block/Mount Lemmon SkyCenter/University of Arizona

With my instrument, Celestron C11, the brighter of the two, NGC 5395, was visible as an elongated, fuzzy nebula, whose long axis was oriented in NE-SW direction. I could quite easily see the relatively bright core of this galaxy, but unfortunately other detail’s weren’t visible with my instrument. The visual length of the long axis was about 2,7′. NGC 5394 was visible as a roundish, fuzzy spot just about 1′ north of NGC 5395. This galaxy seems to have a relatively bright, almost stellar core.

This observing session might be the last one for me during this observing season. But there is still slight chance for observing during coming two weeks before white nights! So keep yourselves tuned for next blogpost, I’m sure to write something before summer!

NGC 5395-4 observed with 11' Catadioptric.
NGC 5395-4 observed with 11′ Catadioptric.

Observing 29./30.3.2014

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Date: 29./30.3.2014
Time: 21:00-02:00
Observing site: Stormälö, Parainen, Finland
Instrument: N250/1200mm

NELM: 6.4
SQM: 21.25
Darkness of the background sky: 1
Seeing: 3
Transparency: 1
Weather: Clear sky, calm to light breeze, no Moon, no snow, humid air, -4 to 0 °C

Obects observed: SS Cyg, R Tri, R Cas, T Cas, NGC 4567-8, NGC 6229

After a wonderful night in Parainen, I went again for observing in Parainen during the following night! During this observing session, observing conditions were nearly as good as they were last night. Only problem during this night was condensation of moisture to all optical surfaces. Otherwise conditions were good: sky was clear, and it was nearly calm all the time. Sky was dark and Moon was absent!

I started this night by observing zodiacal light, which was well visible in the NW sky. Observing zodiacal light is a popular pursuit nowadays in Finland, because now everyone know what to expect and how to observe this phenomena! So now we know for sure, that zodiacal light can be observed at latitude 62, or even higher! My observing site is located little bit north of latitude 60.

Zodiacal light observed 29./30.3.2014 from Parainen, Finland
Zodiacal light observed 29./30.3.2014 from Parainen, Finland

After observing zodiacal light, I went on observing some further-away targets, meaning variable stars and deep sky! First, I tried to observe Leo I, a dwarf galaxy in Leo, near Regulus. I gazed at the right spot, I sweeped around it and tried to catch it with averted vision. Nevertheless, this time I have to make a negative observation of this target. I just couldn’t see it. Sometimes I could see glimpses of something, but I’m not sure that I really saw the dwarf galaxy. I also tried to observe NGC 3115 in Crater, but I decided to give up on it because it was just at too low altitude.

After two not so lucky observing attempt, I decided to observe something I could surely be able to catch! I observed an interacting pair of galaxies, NGC 4567-8 in constellation of Virgo. This pair of galaxies is easy to find, it is located very close to Messier 58 and 59. The galaxies appeared as small, fuzzy elongated patches. This pair of galaxies were connected at their northern edges. The opening angle of the galaxies was about 60 degrees southwards. It was quite easy to separate the galaxies visually. The apparent visual diamater of the galaxy system is about 5′. This one is a really interesting target!

NGC 4567-8 observed with 10'' Newton
NGC 4567-8 observed with 10” Newton

After this pair of galaxies, I aimed my telescope towards constellation of Hercules. In the northern part of this constellation, lies a small globular cluster, NGC 6229. For some reason, I had never observed this target before! At my ocular, this object appeared as a small, round, fuzzy spot. The cluster was not resolved. There isn’t much to see of this object with instrument of this size.

NGC 6229 observed with 10'' Newton
NGC 6229 observed with 10” Newton

After doing some wandering in the realms of deep space, I returned to our own Milky way to do some variable star observations. I observed dwarf nova SS Cyg also this night, and it’s brightness seemed to be same than last night, 8,6 magnitudes. I observed also R Tri, R Cas and T Cas. All of these stars are now close to their minimum brightness, and it would have been impossible for me to observe these stars with my small refractor. R Cyg was so faint, that it wasn’t visible at all with my instrument!

After observing these stars, I decided to go home and get some sleep. I think I just had one of my best observing experiences during this season! Observing conditions were only inch away from being perfect and I could observe many interesting targets! I could also enjoy the wonderful atmosphere of nights of early spring here in Southwestern Finland!

Now it’s April and nights are getting quickly shorter, and phase of the Moon is also getting bigger. It means, that is observing season is soon over. But there are still some observing opportunities in late April and early May!

 

Observing 28./29.3.2014

Date: 28./29.3.2014
Time: 00:00-02:00
Observing site: Stormälö, Parainen, Finland
Instrument: L 102/1000mm

NELM: 6.4
SQM: 21.21
Darkness of the background sky: 1
Seeing: 2
Transparency: 1
Weather: Clear sky, calm, no Moon, no snow, dry air, -3 °C

Objects observed: SS Cyg, Messier 5

In the end of March I finally had a chance to do some deep sky -observing again! In the night between 28th and 29th of March I headed to my observing site in Parainen. Observing conditions during that night were perfect: the sky was absolutely clear, the Moon was absent and it was calm and the air was dry, so there was no condensation problem as usually is the case! It was also pleasently warm, temperature was only 3 degrees below zero! During this winter we haven’t had much winter at all, and that has been the case also during March 2014. During mid March, there was snow on the ground for couple of days, but in late March all snow had melted away!

During this wonderful night I observed dwarf nova SS Cyg and globular cluster Messier 5 in Serpens. This time I noticed SS Cyg to be in outburst, and it’s brightness was about 8,6 magnitudes.

Messier 5 is a famous globular cluster in the constellation of Serpens, and more precisely Serpens Cauda, the Head of the Snake. I observed this cluster with my 4” refractor. With my instrument, the cluster appeared as a bright, concentrated cluster, which gets brighter towards the core. The cluster is resolved nearly to the core. There is a relatively bright star in the western edge of the cluster. The apparent visual diameter of the cluster is roughly 10′. This is a great target for visual observations, also with smaller telescopes!

Messier 5 observed with 4'' refractor
Messier 5 observed with 4” refractor