Some Stars Do Some Stars Dont Reflections on

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

First variable star observed was Theta Apodis, using borrowed 10 x 50 mm binoculars during 1971. Followed in 1972 by S Car, R Cen & T Cen………. .

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.

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

1975 to 1995 BC - 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

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

Observing at Heathcote NSW 30 cm F 6 Newtonian 15 cm F 8 Newtonian 20 x 80 mm binoculars 10 x 50 mm binoculars

Seasonal variation in number of clear nights at Heathcote NSW

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

Filling in a few small holes NSV 5087 Mira star now V 600 Car 274 day period JD 2451646. 1 + 274. 38 +/- 5 X Mus GCVS listed as Unstudied Mira star 266 day period JD 2452085 + 266 +/- 7

30 Papers resulting largely from visual observations obtained at Heathcote 2000 2002 2005 2006 2007 2010 1985 1988 1991 1993 1997 1998 2000 2002 2006 2009 2011 2015 NSV 4189 Hydrae – A Large Amplitude Red Variable - Publ 24 VSS RASNZ = V 371 Hya EO Eridani – A Mira Type Variable - Publ 25 VSS RASNZ NSV 5087 Carinae – A Large Amplitude Red Variable - Publ 25 VSS RASNZ = V 600 Car IY Carinae – A Mira Type Variable Star - JRASNZ V 41 No 1 SW Horologii – A Mira Type Variable Star - JAAVSO V 34 No 2 X Muscae – A Large Amplitude Red Variable - JAAVSO V 34 No 2 V 407 Scorpii – A Revised Period and Epoch for Maximum Brightness – JAAVSO V 35 No 2 NSV 19431 and YY Cen – Two Mira Variables - JAAVSO V 38 No 1 Visual Observations of the 1983 Eclipse of BL Telescopii - Publ 12 VSS RASNZ Visual Observations of the 1985 Eclipse of BL Telescopii - Publ 14 VSS RASNZ A Note on the non-Variability of NSV 12088 Aql - AJA V 2 No 3 Observations of the First Predicted Eclipse of NSV 3005 - AJA V 4 No 2 Visual Observations of BL Telescopii - Publ 18 VSS RASNZ NSV 12088 Aquilae - AJA V 5 No 2 V 854 Cen – The First 3000 Days - Publ 22 VSS RASNZ Visual Observations of the 1994 Eclipse of BL Telescopii - Publ 22 VSS RASNZ Visual Observations of the 1995 Eclipse of OW Geminorum - Publ 22 VSS RASNZ Visual Phase Plots of Some Bright Cepheids - Publ 22 VSS RASNZ Visual Observations of the 1996 Eclipse of BL Telescopii - Publ 23 VSS RASNZ Visual Observations of the 1998 Eclipse of BL Telescopii - Publ 24 VSS RASNZ Theta Apodis – A Bright Semi Regular Variable - Publ 24 VSS RASNZ HDE 331015 – A New Large Amplitude Eclipsing Binary - Publ 25 VSS RASNZ = V 871 Ara BL Telescopii – Visual observations of the Year 2000 Eclipse - Publ 25 VSS RASNZ RY Scorpii– A New Visually Determined Period and Epoch For Maximum Brightness – Publ 25 VSS RASNZ DI Carinae – A Visual Phase Plot - JAAVSO V 34 No 2 T Canis Majoris – A Case of Mistaken Identity - JAAVSO V 34 No 2 A Note on the Variability of CD – 62 466 Carinae - BAA VSSC 141 BL Telescopii – Observations of the 2011 Eclipse - VSSNL 201103 Observations of the 2013 Eclipse of BL Telescopii - VSSNL 201501 FY 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

Catalogue data is not always correct. Visual data shows: V 630 Ara is Mira star Period ~353 days Range 9. 3 - <15. 0 Yet to be published

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

Monitoring little studied stars can also be rewarding – sometimes! BV 520, 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)

BV 520 listed as suspected variable NSV 6708 shown by long term visual observation to be RCB star confirmed spectroscopically after notification of decline onset. Now V 854 Cen.

Hd. C Stars spectroscopically similar to RCB stars but no declines recorded – but nobody has been looking. NSV 11960 Aql HM Lib LV Tr. A NSV 24581 Sgr

1972 – 1977 ~550 day 2010 – 2015 ~510 day R Cen Real change in stellar behaviour 1942 - 2007 Changing amplitude, period & shape of light curve over 65 years

Unexpected happenings, Carbon Stars, obscuration events and confused observers. SX Sco HD 269006 = LMC V 733 UY Cen T CMa

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. 9 UT 778. 4 days interval Next eclipse 2017 Oct 13

A Long Time Ago In A Galaxy Far Away

SN 1987 A 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

Nova Vel 1999 = V 382 Vel Mag 3. 2 at discovery Mag 2. 8 at peak brightness 9 th brightest historically recorded nova Nova Oph 2006 No. 2 = V 2576 Oph Mag 10. 5 at discovery Mag 9. 1 at peak brightness Possibly the faintest visually discovered nova?

The field of EK Tr. A, a faint dwarf nova of changing outburst cycle. Observing can be rewarding, even under full moon. Comet C 1998 P 1 Williams.

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.

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 A wise old astronomer once said – If you are not out there looking, you will only read about it. The End