Observing in coldest temperature so far during this winter

Last night the sky was clear here in sodankylä, and it was also very cold! The coldest temperature last evening was -16 °C! Also the snow cover on the ground has got thicker, now it’s thickness is about 10 cm! The sky was relatively dark last night, because Moon was below horizon. The street lights in the yard of my apartment were interfering, as usually.

Last night I observed R Tri, Z Uma and Z And. There hasn’t been any dramatic, unexpected activity in these stars. R Tri is getting fainter (it’s brightness was 6.7 magnitudes), and now also brightness of Z Uma seems to be dropping, it’s brightness was 7.5 magnitudes. The brightness of Z And has been quite stable since the late July when I started to observe it. It’s brightness yesterday evening was 8.9.

It would have been possible to make even more observations, but I had to quit because I had to go sleeping and my fingers were already almost completely frozen!

Observing session: #24/11-12
Date: 27/28.11.2011
Time: 19.35-21.05
Place: Sodankylä, Finland
Instruments used: L102/1000mm
Objects observed: R Tri, Z Uma, Z And
Conditions: NELM: 5.7, SQM: 19.50, -16 °C, mostly clear sky, calm, no aurorae, no Moon, snow on the ground

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Winter is here!

Winter has now arrived here in Sodankylä! During the nigh between 15/16.11. it started snowing, and there was a good snowcover on the ground in the morning! Snowing continued through the day, but it stopped in afternoon. The snowcover stayed there, it didn’t melt away, because air and especially the ground was already so cold that the snow didn’t melt away!

In yesterday evening (16.11.2011) sky got clear, but I wasn’t able to make observations before late evening – because I had to be working and practising floor hockey with the team of my company! After the practising, I decided to make at least some observations. This time I wasn’t observing my favourite stars, Z Uma and R Tri because I just observed those couple nights ago. This time I observed a variable in Ursa Minor, a star called U Umi. This is a tricky star to find – there are not man bright stars near this one, and that’s why it is not one of the easiest that there are in the sky. This is also the reason for the fact that I havent’t been observing this star in many weeks. Anyway, now I observed it, and I noted that the brightness of this star has dropped from 9.8 to 11.1 – so it is getting fainter!

One thing that is making winter time observing especially challenging is of course coldness – but also snow on the grund. First of all, it is reflecting light in the sky and making the background sky lighter, which means that the observing conditions tend to be worse in winter than in autumn. Another thing is coldness caused by the snow – when observing, I’m much in my knees, and when there is snow on the ground, it makes my knees feel very cold, which is a bit uncofortable. I have been thinking a solution for this problem, one possibility could be using some knee covers made of somekind of soft special plastic that has insulating characteristics. Suitable material for this might be a piece of camping matress that they are selling in outdoors -and sport stores.

So, this was my first observation with snow on the ground during this season!

Observing session: #22/11-12
Date: 16/17.11.2011
Time: 23.00-00.00
Place: Sodankylä, Finland
Instruments used: L102/1000mm
Objects observed: U Umi
Conditions: NELM: 5.7, SQM: 19.67, -3 °C, mostly clear sky, calm, no aurorae, 68% Moon in east at altitude of 18°, snow on the ground!

Winter is close – observing in coldest weather so far during this season

Last night sky got clear here in Sodankylä, and I set my scope up for routine observations. Winter is already very close, and suddenly weather turned very cold in monday night. It had been about +1 – +2 °C for long time, but during monday, temperature was below freezing all day and night and freezing, cold northern wind was blowing. Temperature was about -5 °C, but the freezig factor of the wind made it to feel like -10 °C!

In the evening, I made observations of R Tri and Z Uma, two variable stars that I always find myself obsering! For some reason, these stars have turned into my favourite variables! This time brightness of R Tri had dropped to 5.9, which means decrease of 0.4 magnitudes in 6 days! (I made my last observation in 8.11.2011). First I was quite skeptical and suspicious, but I just had to believe my eyes. And then I plotted my observation on the light curve of recent observations of this star sent to AAVSO, I noticed that my observation is sitting beautifully on the curve! So my observation was correct, and the brightness of this star had suddenly dropped ~0.4 magnitudes. I also noticed that at least according to the light curve, R Tri has a sharp maximum, and it has peaked in late october. Now it is clearly getting fainter again.

Then I observed also Z Uma, which is getting brighter. I estimated it’s brightness to be 7.4, which is still about 0.2 magnitudes less than the average of recent observations in the AAVSO database! So it means, that I’m still underestimating the brightness of this star – a thing that I discussed also in my last post.

And before going in and enjoying some hot blackcurrant juice, I watched quickly Jupiter and the Moon! On the “surface” of Jupiter, I was able to spot a shadow of one of the Jovian moons!

Observing session: #21/11-12
Date: 14/15.11.2011
Time: 22.00-23.05
Place: Sodankylä, Finland
Instruments used: L102/1000mm
Objects observed: R Tri, Z Uma
Conditions: NELM: 5.6, SQM: 19.23, -5 °C, clear sky, cold northern wind, no aurorae, 86% Moon in east at altitude of 30°

Observations in Sodankylä

Last night it was clear sky here in Sodankylä, and I tried to make some observations. There was nevertheless some haze in the sky, and there was a corona visible around Moon. And then I also noticed, that some street lights that had been broken in the yard of my apartment were fixed – a fact that caused a slight increase in the amount of light pollution. Anyway, I could make couple of observations, I observed R Tri and Z Uma. R Tri has now passed it’s maximum, and it’s brightness was about 5.5 magnitudes, the maximum brightness of this star is approximately 5.3-5.4. Z Uma has been getting even brighter.

And then I noticed one thing about my observations of Z Uma, I have been constantly underestimating the brightness of this star (when comparing with the average observations of this star in the database of AAVSO during my latest observing attempts). This time I estimated that the brightness of the star was about 7.5, which is about 0,5 magnitudes lesser than the average of the estimations, at least when estimating the average visually. I wonder, why this might be happening. One reason could be the comparison star interval – in the comparison chart of AAVSO (reversed B for visual observations), there are not any stars with magnitude ~6, and it might be affecting my estimate. I compared the variable with the star of magnitude 7.9 and 5.8. This interval is fairly large, and I think it might be useful to have a star that has a magnitude between these stars. There are some stars with magnitude with ~6, but they are quite far away from the variable itself.

The asteroid 2005YU55 could have been visible, but I wasn’t able to print out any maps, and also the object was at low altitude in the horizon of Sodankylä, and also in early evening (when it could have been visible) there was haze in the sky which made observing difficult. And also the Moon was interfering severely. Because of these reasons, I didn’t do any observing attempt of this object.

Observing session: #20/11-12
Date: 8/9.11.2011
Time: 20.45-22.15
Place: Sodankylä, Finland
Instruments used: L102/1000mm
Objects observed: R Tri, Z Uma
Conditions: NELM: 5.3, SQM: 18.76, -1 – -2 °C, clear sky, some haze in the sky, calm, no aurorae, 96% Moon in south at altitude of 30°

The sky of the month: November 2011

In november, darkness prevails here in the north, and chances for making astronomical observations are good! During early evening (picture 1.), the familiar constellations of autumn sky are still high in southern-southwestern sky. The Great Pegasus -square is in the southeastern sky and the constellations of Milky Way are in the southwest. In the morning (picture 3.), the winter -constellations are visible in the south. The mighty constellation of Orion, The Hunter, will be dominating the view in the south with Taurus, Gemini and Canis Minor and -Major. The brightest star of the sky, Sirius, is visible at low altitude in south. And just before sunrise (in the southern latitudes, where sun will rise) , constellations of Leo, Cancer and Hydra are visible in southern sky (picture 3.).

In November, planet Jupiter will be visible during all night in constellation of Aries (pictures 1 and 2.). Uranus and Neptune are visible at low altitude during early evening in southern sky. Uranus is visible also with naked eye in dark place (picture 1.), you just have to know where to look at! Neptune won’t be visible without telescope. Mars will be visible in the morning before sunrise in constellation of Leo.

Comet Garrad will be visible in the evening, and because the night is so long in November, it is also possible to see the comet just before sunrise! The Leonides -meteor shower is active in 17. of November, but this year the activity will be quite low, only 10-20 meteors are expected to be seen per hour.

Northern lights are likely to be seen in clear nights in November as a consequence to rising solar activity.

Celestial events in November:

2.11.2011

First quarter of Moon

9.11.2011

Moon close to Jupiter

10.11.2011

Full Moon

14.11.2011

The greatest eastern elongation of Mercury

17.11.2011

Maximum of the Leonides

18.11.2011

The Last quarter of Moon

19.11.2011

Venus close to Moon

22.11.2011

Saturn close to Moon, Sun enters Sagittarius

25.11.2011

New Moon

26.11.2011

Mercury close to Moon

27.11.2011

Venus close to Moon