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Some Stars Do & Some Stars Don’t Reflections on 45 Years of Variable Star Observing – Peter Williams.

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Presentation on theme: "Some Stars Do & Some Stars Don’t Reflections on 45 Years of Variable Star Observing – Peter Williams."— Presentation transcript:

1 Some Stars Do & Some Stars Don’t Reflections on 45 Years of Variable Star Observing – Peter Williams

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3 Followed in 1972 by S Car, R Car, R Cen & T Cen……….. First variable star observed was Theta Apodis, using borrowed 10x50mm binoculars during 1971.

4 Variable Star Section, RASNZ formed in 1927 by Frank Bateson who remained Director through to 2004. After Bateson’s retirement the VSS evolved into Variable Stars South, the new VSS as we know it today. First observations submitted to VSS in 1975 Longest continuous series of observations for S Carinae – 45 years.

5 Einstein Observatory HEAO 2 1978-1981 International Ultraviolet Explorer 1978-1996 Hubble Space Telescope 1990-2016+ PAGEOS 1975

6 1975 to 1995BC -hand written monthly reports -Pen, paper & typewriter Special Programs - Dwarf novae, RCB, Symbiotic stars & pre main sequence stars - reporting by telegram or operator connected phone call

7 The Old VSS in print - Instruction Manual - Publications - Monthly Circulars - Newsletter: Changing Trends

8 Observing at Heathcote NSW 30cm F6 Newtonian 15cm F8 Newtonian 20x80mm binoculars 10x50mm binoculars

9 Seasonal variation in number of clear nights at Heathcote NSW

10 No comparison star sequences Basic catalogue data often missing Undertook personal program to fill some missing catalogue data Star Charts – early VSS & AAVSO charts often of poor quality

11 NSV5087 Mira star now V600 Car 274 day period JD2451646.1 + 274.38 +/- 5 X Mus GCVS listed as Unstudied Mira star 266 day period JD2452085 + 266 +/- 7 Filling in a few small holes

12 30 Papers resulting largely from visual observations obtained at Heathcote 2000NSV4189 Hydrae – A Large Amplitude Red Variable- Publ 24 VSS RASNZ= V371 Hya 2002EO Eridani – A Mira Type Variable- Publ 25 VSS RASNZ 2002NSV5087 Carinae – A Large Amplitude Red Variable- Publ 25 VSS RASNZ= V600 Car 2005IY Carinae – A Mira Type Variable Star- JRASNZ V41 No1 2006SW Horologii – A Mira Type Variable Star- JAAVSO V34 No2 2006X Muscae – A Large Amplitude Red Variable- JAAVSO V34 No2 2007V407 Scorpii – A Revised Period and Epoch for Maximum Brightness – JAAVSO V35 No2 2010NSV19431 and YY Cen – Two Mira Variables- JAAVSO V38 No1 1985Visual Observations of the 1983 Eclipse of BL Telescopii- Publ 12 VSS RASNZ 1988Visual Observations of the 1985 Eclipse of BL Telescopii- Publ 14 VSS RASNZ 1988A Note on the non-Variability of NSV12088 Aql- AJA V2 No3 1991Observations of the First Predicted Eclipse of NSV3005- AJA V4 No2 1993Visual Observations of BL Telescopii- Publ 18 VSS RASNZ 1993NSV12088 Aquilae- AJA V5 No2 1997V854 Cen – The First 3000 Days- Publ 22 VSS RASNZ 1997Visual Observations of the 1994 Eclipse of BL Telescopii- Publ 22 VSS RASNZ 1997Visual Observations of the 1995 Eclipse of OW Geminorum- Publ 22 VSS RASNZ 1997Visual Phase Plots of Some Bright Cepheids- Publ 22 VSS RASNZ 1998Visual Observations of the 1996 Eclipse of BL Telescopii- Publ 23 VSS RASNZ 2000Visual Observations of the 1998 Eclipse of BL Telescopii- Publ 24 VSS RASNZ 2000Theta Apodis – A Bright Semi Regular Variable- Publ 24 VSS RASNZ 2002HDE331015 – A New Large Amplitude Eclipsing Binary- Publ 25 VSS RASNZ= V871 Ara 2002BL Telescopii – Visual observations of the Year 2000 Eclipse - Publ 25 VSS RASNZ 2002RY Scorpii– A New Visually Determined Period and Epoch For Maximum Brightness – Publ 25 VSS RASNZ 2006DI Carinae – A Visual Phase Plot- JAAVSO V34 No2 2006T Canis Majoris – A Case of Mistaken Identity- JAAVSO V34 No2 2009A Note on the Variability of CD –62 466 Carinae- BAA VSSC 141 2011BL Telescopii – Observations of the 2011 Eclipse- VSSNL 201103 2015Observations of the 2013 Eclipse of BL Telescopii- VSSNL 201501 2015FY Librae – A first look at the behaviour during 2014- BAA VSSC 163 Refereed Publication of results is important but all too often overlooked. JAAVSO VSSNL

13 Catalogue data is not always correct. Visual data shows: V630 Ara is Mira star Period ~353 days Range 9.3 - <15.0 Yet to be published

14 Classical Cepheid Phase Plots 2008 – 2009 suggested that maybe not all is well. U Car RZ Vel SW Vel DI Car

15 Monitoring little studied stars can also be rewarding – sometimes! BV520, catalogued as small amplitude red variable, mag 9.7 range of 0.9 mag Distinction of being discovered 3 times : 1964 (Bamberg), 1971 (Welch) and 1986 (Dawes)

16 BV520 listed as suspected variable NSV6708 shown by long term visual observation to be RCB star confirmed spectroscopically after notification of decline onset. Now V854 Cen.

17 HdC Stars spectroscopically similar to RCB stars but no declines recorded – but nobody has been looking. NSV 11960 AqlLV TrA HM LibNSV 24581 Sgr

18 R Cen Real change in stellar behaviour Changing amplitude, period & shape of light curve over 65 years 1972 – 1977 ~550 day2010 – 2015 ~510 day 1942 - 2007

19 Unexpected happenings, Carbon Stars, obscuration events and confused observers. UY CenT CMa SX Sco HD269006 = LMC V733

20 BL Telescopii Long period eclipsing binary of period 778.6 days with 12 successfully observed eclipses since 1983. Subject of long term visual program running 32 years and counting…… BL Tel 2015 Mid eclipse 2015 Aug 28.9UT 778.4 days interval Next eclipse 2017 Oct 13

21 A Long Long Time Ago In A Galaxy Far Far Away

22 SN 1987A LMC 1 st Naked Eye Super Nova 400+ Years Yes, the Tarantula Nebula looks great! Peak brightness 2.8 magnitude Visible to naked eye for some 200 days Visible through telescope for further 900 days

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25 Nova Vel 1999 = V382 Vel Mag 3.2 at discovery Mag 2.8 at peak brightness 9 th brightest historically recorded nova Nova Oph 2006 No.2 = V2576 Oph Mag 10.5 at discovery Mag 9.1 at peak brightness Possibly the faintest visually discovered nova?

26 The field of EK TrA, a faint dwarf nova of changing outburst cycle. Observing can be rewarding, even under full moon. Comet C1998P1 Williams.

27 As amateurs, observing variable stars is certainly a noble pursuit. Contributing to our knowledge of the stars Pushing back the frontiers of science Adding to our understanding of the universe in which we live.

28 A wise old astronomer once said – If you are not out there looking, you will only read about it. As amateurs, observing variable stars is certainly a noble pursuit. Contributing to our knowledge of the stars Pushing back the frontiers of science Adding to our understanding of the universe in which we live. But I do it because observing variable stars is fun! And may also contribute a little to science along the way The End


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