Newest observations

Contact information

Taivaanvahti,
Ursa Astronomical Association
Kopernikuksentie 1
00130 Helsinki
taivaanvahti(at)ursa.fi

Ursa Astronomical Association

1 observations and 3 comments in queue.

Only observations that have a description and at least one image attached.

Kaukoputkella näkyvä komeetta NEOWISE

18.3.2021 klo 21.31 - 23.45 - Helsinki, Maunula (I)
Jorma Ryske, Etelä-Suomen kosmol. seura

Comet C/2021 A2 (NEOWISE) is now much dimmer than I last observed it at February 16th. In this 115min exposure using 387nm narrowband filter cyanogen CN 3883Å radical gas coma diameter is 0,6'/40.000km and wide fan-shaped cyanogen gas tail length 1'/60.000km towards PA 330° is visible. Comet current distance from sun is 1,62au and from earth 1,43au. I took also R channel photometric image and although the image had poor S/N I measured comet R channel brightness as 16,3mag. CN channel brightness measurement is difficult because lack of 3883Å reference stars, not very scientific but when using B...

Kaukoputkella näkyvä komeetta NEOWISE

16.2.2021 klo 22.15 - 23.55 - Helsinki, Maunula (II)
Jorma Ryske, Etelä-Suomen kosmol. seura

Comet C/2021 A2 (NEOWISE) cyanogen CN radical gas coma diameter 1,7'/50000km and wide fan-shaped cyanogen gas tail length 3,4'/100000km towards PA 10° is visible in this 3870Å narrowband filter image. Comet distance from sun is 1,46au so the sun heat and UV radiation is strong enough to sublimate comet icy surface and photodissociate gases like CN at 3883Å.    Image 1) 30x180s=90min with CN 387nm narrowband filter at 2021-02-16 20:15-21:50UT Image 2) Processed cropped image 1 with CometCIEF to enhance coma and tail morphology. No significant details visible.

Images: 2 pcs

Kaukoputkella näkyvä komeetta ATLAS

9.12.2020 klo 21.44 - 03.14 - Helsinki, Maunula (II)
Jorma Ryske, Etelä-Suomen kosmol. seura

C/2020 M3 (ATLAS) is moving farther away from earth but is still relatively near at distance 0,45AU. I tried to observe comets rotating CN gas jet which was visible earlier 20.11.2020. Seems that the CN jet is still visible but clear rotation is no more observable. Figure 1) CN 387nm filter 18*5min exposure starting at 2020-12-09 22:47UT, showing large 15' (equivalent to 300 000 km) cyanogen coma around oval shaped optocenter. FoV 36' x 29'. Figure 2) G filter 20x20s image at 2020-12-09 19:56UT showing tail 4'. FoV 36' x 29'. Figure 3) R filter 20x20s image at 2020-12-09 19:44UT showing dust t...

Images: 4 pcs

Kaukoputkella näkyvä komeetta ATLAS

20.11.2020 klo 22.50 - 05.13 - Helsinki, Maunula (III)
Jorma Ryske, Etelä-Suomen kosmol. seura

Comet C/2020 M3 (ATLAS) is quite near earth 0,36au and it's Sun distance is 1,33au. It is emitting cyanogen CN gas with rate Q(CN)=1.62+ E25 s-1 (14.11.2020 http://www.astronomerstelegram.org/?read=14174). It is about the same rate as 46P/Wirtanen had two years ago (18.12.2018 Q(CN)= 1.17E+25 s-1) of which rotating CN jet was then clearly observed. Image 1) Animation of 4 frames, each stacked 60 minute exposure through CN/387nm narrowband filter and CometCIEF processed. Some amount of CN jet rotation is visible during ~4 hours of frames mid-exposures. Image 2) CN filter exposure 12x300s=60 min...

Images: 3 pcs

Paljain silmin himmeä pyrstötähti NEOWISE

10.7.2020 klo 01.00 - 02.00 - Helsinki, Haltiala (IV)
Jorma Ryske, Etelä-Suomen kosmol. seura

C/2020 F3 (Neowise) piti bongata vaikka se hyvin valoisalla heinäkuun alkupuolen pohjoistaivaalla lymyilikin. Pohjois-Helsingin Haltialan pelloilta on hyvä näkyvyys pohjoiseen melkein horisonttiin asti, sinne siis aamuyöllä koettamaan löytyykö komeetta. Aluksi Capellakin oli piilossa valaisevien yöpilvien takana, mutta sen löydyttyä oli suuntimat suunnilleen tiedossa ja 10x42 kiikareilla löytyi komeettakin hetken päästä. Kun valaisevien yöpilvien haituvat siirtyivät niin että komeetta jäi niiden väliin sopivasti pilvettömään kohtaan "paikkamerkittynä", erottui se aika helposti komeettamaisena ...

Images: 3 pcs • Comments: 1 pcs

Kaukoputkella näkyvä komeetta ATLAS

10.4.2020 klo 22.07 - 23.00 - Helsinki, Maunula (III)
Jorma Ryske, Etelä-Suomen kosmol. seura

Comet C/2019 Y4 (ATLAS) is disintegrated and preceding fragment is visible in this R-channel image. Fragment is 10" from comet's main optocenter towards PA 285°. Main image is 25x120s frame stack and two other 12x120s image stacks 30 minutes between.   Image 1) R filter 25x120s 2020-04-10 19:07UTImage 2) R filter 12x120s 2020-04-10 19:07UTImage 3) R filter 12x120s 2020-04-10 19:35UT   Image 4) Added strongly stretched version of Image 1. Three fragments can be seen, second fragment preceding first most behind fragment of 7" PA260° and third fragment preceding first most behind of 12" PA290°  

Images: 4 pcs

Kaukoputkella näkyvä komeetta ATLAS

9.4.2020 klo 22.10 - 23.27 - Helsinki, Maunula (III)
Jorma Ryske, Etelä-Suomen kosmol. seura

Comet C/2019 Y4 (ATLAS) optocenter is strongly oval shaped in all colour channels RGB and UV/CN and there is not point like optocenter visible representing comet's possible disintegration. Moon phase was 95% but fortunately it was low in the sky. Image 1) Crop of Astrodon R filter (image 3) showing strongly oval shaped optocenter. One fragment can be seen preceding/leading very close optocenter, measured 9" towards PA 290° / "2:30 o'clock"Image 2) Astrodon G filter showing 7' diameter coma and 11' tail towards PA 95°, exposure time 10 minutes. Image 3) Astrodon R filter showing 3' diameter com...

Images: 6 pcs

Kiikarikomeetta ATLAS

4.4.2020 klo 22.03 - 23.42 - Helsinki, Maunula (III)
Jorma Ryske, Etelä-Suomen kosmol. seura

Comet C/2019 Y4 (ATLAS) was strongly interfered by moon (85%) so coma and tail measurement are not comparable to my earlier observations under "darker" Helsinki normal light polluted sky.   Image 1) Astrodon G filter showing 7' diameter coma and 6' tail towards PA 105°, exposure time 10 minutes. Image 2) Astrodon R filter showing 2' diameter coma and 5' dust tail towards PA 105°, exposure time 11 minutes. Image 3) Astrodon B filter showing 3' diameter coma and 5' tail towards PA 105°, exposure time 10 minutes. Image 4) CN 387nm narrowband filter showing cyanogen 3883Å gas coma about 11' diamet...

Images: 5 pcs

Kiikarikomeetta ATLAS

30.3.2020 klo 22.28 - 01.07 - Helsinki, Maunula (III)
Jorma Ryske, Etelä-Suomen kosmol. seura

Comet C/2019 Y4 (ATLAS) is now 1,05au from earth and 1,50au from sun and brightening all the time.   Image 1) Astrodon G filter showing 8' diameter coma and 5' tail towards PA 120°, exposure time 10 minutes. Image 2) Astrodon R filter showing 2' diameter coma and 4' dust tail towards PA 120°, exposure time 15 minutes. Image 3) Astrodon B filter showing 4' diameter coma and 8' tail towards PA 120°, exposure time 10 minutes. Image 4) Semrock CN 387nm narrowband filter showing cyanogen 3883Å gas coma about 18' diameter and dim tail towards PA 120°. Exposure time 60 minutes. Cyanogen gas coma visi...

Images: 5 pcs • Comments: 2 pcs

M87 Black Hole Jet

22.3.2020 klo 02.00 - 03.10 - Helsinki, Maunula (III)
Jorma Ryske, Etelä-Suomen kosmol. seura

Koitin saisiko kapeakaista UV suodattimella M87 mustan aukon kuuluisaa relativistista suihkua jotenkin selvemmin näkyviin. Ei se kuitenkaan silmiinpistävästi tässä RGB valotuksiin verrattuna erotu, mutta ehkä vähän "kuumaa sinivalkoista" jetissä näkyy. Ohessa RGB kuvassa UV valotukset on laitettu B kaistaan. Tämä kohde vaatii pidempää polttoväliä, 1200mm on liian vähän. RGB valotukset 10min ja UV 387nm 40min. Lisätty kropattu kuva pelkästä kapeakaista 387nm UV filtterin valotuksesta.

Images: 2 pcs • Comments: 4 pcs

Kiikarikomeetta ATLAS

21.3.2020 klo 20.39 - 03.22 - Helsinki, Maunula (III)
Jorma Ryske, Etelä-Suomen kosmol. seura

Comet C/2019 Y4 (ATLAS) is now 1,08au from earth and 1,64au from sun. Sun is warming it and also sun's UV radiation has started photodissociation reactions on comet surface.   Image 1) Astrodon G filter showing 6' diameter coma and 5' tail towards PA 145°, exposure time 15 minutes. Image 2) Astrodon R filter showing 2' diameter coma and 4' dust tail towards PA 145°, exposure time 15 minutes. Image 3) CN 387nm narrowband filter showing cyanogen 3883Å gas coma about 11' diameter and dim tail towards PA 145°. Exposure time 60 minutes. Image 4) Image 3 processed with CometCIEF showing tail 4' towa...

Images: 4 pcs

Kiikarikomeetta ATLAS

20.3.2020 klo 21.55 - 01.30 - Helsinki, Maunula (III)
Jorma Ryske, Etelä-Suomen kosmol. seura

Comet C/2019 Y4 (ATLAS) here in plain UV 387nm light. Sun is warming comet surface and sun's UV radiation has started photodissociation reactions creating interesting  inorganic molecules like cyanogen radical -CN.   Image 1) CN 387nm narrowband (15nm) filter showing cyanogen 3883Å gas coma about 12' diameter and dim 5' tail towards PA 145°. Exposure time 210 minutes.   Image 2) Image 1 processed with CometCIEF showing tail 4' towards PA 145° which is scattered sun light from dust tail particles. Towards PA 240° can be seen wide CN Cyanogen gas jet.

Images: 2 pcs

Kiikarikomeetta PANSTARRS

24.1.2020 klo 19.19 - 21.45 - Helsinki, Maunula (III)
Jorma Ryske, Etelä-Suomen kosmol. seura

C/2017 T2 (PanSTARRS) is now 1,6au from earth and 2,1au from sun. Image 1) Astrodon G filter showing 5' diameter coma and 14' tail towards PA 140°, exposure time 15 minutes. Image 2) Astrodon R filter showing 2' diameter coma and 7' dust tail towards PA 140°, exposure time 15 minutes. Image 3) CN 387nm narrowband filter showing cyanogen 3883Å gas coma about 8' diameter and dim  tail towards PA 140°. Exposure time 120 minutes. Image 4) Image 3 processed with CometCIEF showing wide tail 4' towards PA 140°. Tail visible in this 387nm narrowband filtered image is probably mainly scattered sun ligh...

Images: 5 pcs

Kiikarikomeetta PANSTARRS

3.1.2020 klo 22.51 - 00.26 - Helsinki, Maunula (III)
Jorma Ryske, Etelä-Suomen kosmol. seura

C/2017 T2 (PanSTARRS) was observed in strong wind gusts shaking telescope during exposures and because of that about every third images cannot be used in stacking. Image 1) Astrodon G filter showing 2' diameter coma and 10' tail towards PA 160°, exposure time 7,5 minutes. Image 2) Astrodon R filter showing 2' diameter coma and 8' dust tail towards PA 160°, exposure time 7,5 minutes. Image 3) CN 387nm narrowband filter showing cyanogen 3883Å gas coma about 4' diameter and dim tail 5' towards PA 160°. Exposure time 35 minutes. Image 4) Image 3 processed with CometCIEF showing tail 7' towards PA ...

Images: 4 pcs

Kiikarikomeetta PANSTARRS

30.12.2019 klo 23.07 - 01.05 - Helsinki, Maunula (III)
Jorma Ryske, Etelä-Suomen kosmol. seura

C/2017 T2 (PanSTARRS) is now about mag 9,5 comet high in evening sky, moving quite slow and distance from earth is 1,52AU. Image 1) Astrodon G filter showing 2' diameter coma and 12' tail towards PA 170°, exposure time 18 minutes. Comet optocenter was passing directly over star GSC 3707:430 mag11,2 during exposure. Image 2) CN 387nm narrowband filter showing cyanogen 3883Å gas coma about 4' diameter and dim possible cyanogen gas tail 5' towards PA 160°. Exposure time 70 minutes. Image 3) Image 2 processed with CometCIEF showing possible cyanogen gas tail 7' towards PA 160°. Image 4) Two frame ...

Images: 4 pcs

Kaukoputkella näkyvä komeetta McNaught

29.10.2019 klo 20.25 - 23.00 - Helsinki, Maunula (II)
Jorma Ryske, Etelä-Suomen kosmol. seura

260P/McNaught is now about mag12 comet high in evening sky and distance from earth about 0,6AU. Image 1) IDAS LPS filter showing about 4' tail towards PA 230°, exposure time 15 minutes. Image 2) CN 387nm cyanogen gas filter showing cyanogen coma about 3' diameter. Exposure time 90 minutes. Image 3) Like image 2 but processed with CometCIEF showing cyanogen gas tail/jet to about same direction as dust tail in image 1, 3' towards PA 220°-250°   Comet coma magnitude is 12.07 using Astrometrica and Comphot.

Images: 3 pcs

Kiikarikomeetta Iwamoto

24.2.2019 klo 20.16 - 23.33 - Helsinki, Maunula (III)
Jorma Ryske, Etelä-Suomen kosmol. seura

Comet C/2018 Y1 Iwamoto is in Auriga and still quite near earth at distance 0,55AU and moving fast 5'/h westwards.   Animation 1) Iwamoto through CN 387nm narrowband filter, 36x5 minute exposures during 3 hour observing time. Three stacked images each 12x5min=1 hour and then CometCIEF processed to 3 frame animation showing CN cyanogen jet rotating around comet optocenter ccw from about PA 0° to about PA 70°. Error marginal in PA measurement is significant. N Up, E Left, FoV 14'x14'. Stacked frames mid times 2019-02-24T18:53UT, 2019-02-24T20:00UT and 2019-02-24T21:02UT. Image 2) Astrodon G filt...

Images: 2 pcs

Kiikarikomeetta Iwamoto

12.2.2019 klo 21.55 - 00.52 - Helsinki, Maunula (III)
Jorma Ryske, Etelä-Suomen kosmol. seura

Comet C/2018 Y1 (Iwamoto) is moving very fast in Leo's Sickle, about 1.5' during each five minute exposures taken through narrowband UV 387nm CN cyanogen filter. CometCIEF processed animation show CN jet towards PA 295°. Some movement during 3h observing time exists, but not a clear jet rotation. CN coma diameter is about 25', almost filling the whole FoV 47'x 38' image.  Image 1) 387nm CN filter, animation of 3 frames each 10x300s and CometCIEF processed. Exposures between 2019-02-12T19:50 - 2019-02-12T22:47 UTC Image 2) 387nm CN filter, stacked 10x300s

Images: 2 pcs

Kiikarikomeetta Wirtanen

11.1.2019 klo 17.50 - 05.00 - Helsinki, Maunula (III)
Jorma Ryske, Etelä-Suomen kosmol. seura

46P/Wirtanen is still actively emitting CN cyanogen radical gas jets and it's distance from Earth is about 0,18AU. Here in first image Wirtanen is exposed 3 hours at near UV 387nm narrowband wavelength, where about 30' diameter coma is visible. In the second image Wirtanen is exposed with R filter, where short dust tail of length 3' toward PA 210° is visible. I made also almost all night long exposures with CN 387nm cyanogen filter, totalling of more than 10 hours of 5 minute exposures during 11 hour of observing time. Few clouds was passing over during evening and meridian flip must also be d...

Images: 3 pcs • Comments: 2 pcs

Kiikarikomeetta Wirtanen

3.1.2019 klo 17.35 - 20.56 - Helsinki, Maunula (III)
Jorma Ryske, Etelä-Suomen kosmol. seura

46P/Wirtanen is receding but still quite near Earth at a distance about 0,14AU. Here in first image Wirtanen is exposed at near UV 387nm narrowband wavelength, where about 30' diameter coma is visible. In the second image Wirtanen is exposed with R filter, where short dust tail of length 4' toward PA 210° is visible. I used CometCIEF processing (Samarasinha, N. H., Martin, M. P., Larson, S. M, 2013. Cometary Coma Image Enhancement Facility, http://www.psi.edu/research/cometimen) to enhance 387nm stacked images to visualize possible rotation effect of cyanogen radical CN jets. In the third imag...

Images: 3 pcs

Search result contains observations from time period 1.1.2000 klo 00.00 - 11.5.2021 klo 19.00.