3 Years Occultation Observation at new K71 Observatory. Experiences and Results. Dr. Björn Kattentidt Rokycany, 25./26. Aug. 2018

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1 3 Years Occultation Observation at new K71 Observatory Experiences and Results Dr. Björn Kattentidt Rokycany, 25./26. Aug. 2018

2 Overview K71, pictures, equipment Selection criteria for observation planning Short movies of POSITIVE observations Light curves

3 Observatory K71

4 Telescope Mount Camera Equipment Device Product Remark Video time inserter with GPS Celestron 11 SC f/10 on CGE-Pro Watec 910HX/RC (QHY 174 Mono?) VTI by Sven Andersson Garmin GPS 18x LVC Frame grabber Digitus 70820, (Hauppauge Live 2) Recording (VirtualDub 1.8.6) SharpCap V3.1 Hard drive, Interface Software, OS Problematic programs Samsung SSD 850 Pro, USB3 C2A Limovie, (Tangra/AOTA) Windows 10 pro & XP pro Occult Watcher Virus scanner Firewall, LAN optimal collimated! reducer f/6,3 battery supported! analogue digitizer 25fps exactly lossless fast! 0 dropped frames fast processor fast main board no autonomous background run

5 Observation planning brightness duration diameter probability selection criteria? drop feed frames distance central line Motivation: Reduction of negative observations!

6 POS 2015 POS 2016 POS 2017 POS 2018 NEG 2015 NEG 2016 NEG 2017 NEG 2018 Observation statistics 440 observations during nearly 3 years, 12 POSITIVE Time scale Jan Feb Mrz Apr Mai Jun Jul Aug Sep Okt Nov Dez

7 Brightness? Brightness combined [mag] count NEG count POS <8 8.x 9.x 10.x 11.x 12.x 13.x 14.x 15.x 16.x 17+

8 Drop? Drop magnitude count NEG count POS 60 P T <0,3 0,3+ 0, (2%) 8(7%) #POS (reduced obs)

9 Diameter! Diameter minor planet [km] < (36%)11(55%) P T count NEG count POS #POS (reduced obs)

10 Probability! Predicted obs location [%] T P <0,5 0, count NEG count POS 10 (24%) 7(80%) #POS (reduced obs)

11 Distance central line? Distance to central line [km] T count NEG count POS P < (27%) 11(5%) #POS (reduced obs)

12 Ratio: distance CL / diameter! Distance to central line / diameter [part] T P <0,1 0,1+ 0,2+ 0,4+ 0, count NEG count POS 7(87%) 9(61%) #POS (reduced obs)

13 Maximum duration (!) Maximum duration [s] count NEG count POS <0,3 0,3+ 0,5+ 0, (9%) 8(75%) 65 3 T P #POS (reduced obs)

14 Frames possible... Maximum frames possible count NEG P T count POS < (3%) 8(66%) #POS (reduced obs)

15 IOTA IBEROC UKOCL LINOCC OWEvents NAmer COMETOCC RIO-TNO EURASTER Feed Feed P T 2 0 count NEG count POS

16 All criteria applied For several criteria only use weak exclusions! or: Exclude only ineffective observations

17 Value Value Avoidable observations Summary - optimal single criterion Single criterion used only 100,0% 90,0% 80,0% 98% 97% 95% 93% 91% 94% 92% 91% 91% 84% 80% diameter 70,0% 60,0% 50,0% 40,0% 73% 65% 59% 54% 39% ratio: dist. CL / diam. duration frames probability 30,0% 20,0% 10,0% 38% 14% 21% 16% distance CL drop 0,0% Quantity observable POSITIVEs Criterion threshold single criterion Criterion threshold single criterion 7,0 2,8 0,3 0,5 0,5 0,6 1,3 10,8 16,6 22, Quantity of observable POSITIVEs Quantity of observable POSITIVEs

18 Results: Positive observations (65) Cybele occults 4UC , IBEROC (53418) 1999 PY3 occults UCAC , LINOCC (134340) Pluto occults 4UC , RIO TNO (426) Hippo occults UCAC , OWEvents (27438) Carolynjons occults 4U , IBEROC (3) Juno occults 2UCAC , IOTA (539) Pamina occults 2UCAC , IOTA (11921) Mitamasahiro occults UCAC , LINOCC (2067) Aksnes occults UCAC , LINOCC moon Triton occults 4UC , RIO TNO (17626) 1996 AG2 occults 4U , UKOCL (31) Euphrosyne occults 4UC , OWEvents clouds airplane

19 1. Long integration 2,56 sec., clouds, low drop 0,3m predicted edge 1 sigma segmented avi peak of bg noise reference stars measurement normalized

20 2. Low probability 1,2%, only 3 frames predicted 1,2 sec. at 4 frames measured

21 3. Prominent occultation, athmosphere, 1,1 mag drop predicted problematic circumstances... artificial reference star light curve

22 4. Only 0,1 mag drop, 9,2 sec. duration... but uncertain due to noise compared to low drop

23 5. Double star?! prediction 6,1mag drop, but only 1 mag observed

24 6. Only 0,2 mag drop but prominent

25 7. Classical occultation 9 sec. duration with clouds

26 8. Only 3 of 5 possible frames (0, ,48 sec.)

27 9. Classical occultation

28 10. Saturn moon Triton and athmosphere problematic circumstances...

29 11. Another double star? prediction 7,7 mag drop, but only 1,9 mag observed

30 12....confirmed by Tony George prediction 0,29 mag drop, 0,25 mag 95% confidence, SNR 1,6

31 33 heigth occultation ca. 0,2 seconds, max. 0,3 biggest airliner independant from height, distance and flight direction only ratio length / velocity is relevant for artificial occultation duration

32 Thanks! K71 Neutraubling near Regensburg / germany

33 mag star mag star Magnitude calculation magnitude drop combined magnitude 14, , , ,5 0, mag object ,5 6, ,5 5, ,5 4, ,5 3, ,5 2, ,5 1, ,5 0, , mag object , ,5 11, ,5 10, ,5 9, ,5 8, ,5 7, ,5 6, ,5 5, ,5 4, ,5 3,5-4

34 (66062) 1998 RG1 occults 4U , , Wolken

35 (42519) 1994 AU6 occults 4U , , clouds