Journal of Double Star Observations V5, No4

Vol. 15 No. 3 July 1, 2019 Page 421 Journal of Double Star Observations

Introduction Commencing in 2008, the Double Star Section of

the AAQ submits the 2016 results given in Table 1 as part of an ongoing program. The target stars were se-lected from the Washington Double Star Catalog (WDSC) and were observed in Queensland from a lati-tude of approximately 27° S.

Method Once obtained with the equipment described above,

the images were analysed using the astrometric double star program REDUC (Losse, 2008). Approximately ten stacked images of each target were taken per night for seven nights and the results averaged to obtain measures of separation and position angle with suffi-cient confidence.

Full details of the method are given in Napier-Munn and Jenkinson (2009). Some recent work on the errors inherent in the method is described in Napier-Munn and Jenkinson (2014). As proficiency has grown in the use of this equipment with the 400mm reflector, close doubles with considerable magnitude difference between the components have been successfully meas-ured.

Results For all of the systems shown below the WDSC in-

formation is first reproduced, showing the epoch 2000 position, magnitudes, separation, PA, and the last rec-

orded measurement. The new measurements are then given in tabular form, including the mean and standard deviation and 95% confidence limits. Any uncertainties between the images and the last recorded measurements are discussed. Finally a conclusion is given as to wheth-er any movement of the component stars has occurred in PA or separation, based on the P-value for the t-test comparing the new mean values with the cataloged val-ue (P < 0.05 is considered as evidence of change).

For reference purposes a sample image of each tar-get pair has been included with this report. Please note that all attached images are aligned with North to the bottom and East to the right.

Acknowledgements This research has made use of the Washington

Double Star Catalog maintained at the U.S. Naval Ob-servatory.

The Edward Corbould Research Fund administered by the Astronomical Association of Queensland for granting of funds to upgrade imaging camera and ob-servatory computer to suit.

Fellow AAQ member Des Janke for his work in processing the original FITS image files into JPEG photographs for this Circular.

Fellow AAQ members Culshaw, Hughes and Hughes provided invaluable assistance with image pro-cessing using Losse’s REDUC software.

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Astronomical Association of Queensland 2016 Results: Bluestar Observatory Measurement of

Twenty Neglected Southern Multiple Stars

Peter N. Culshaw, Diane Hughes, John Hughes, Graeme Jenkinson, D. Janke

Astronomical Association of Queensland. [email protected]

Abstract: This paper presents the final results of a 2016 program of photographic meas-urements of twenty southern multiple stars. All results were obtained using an Atik 460EX mono CCD camera used in conjunction with an equatorially mounted 400mm F4.5 Newtonian reflector.The mean 95% confidence intervals for the new measures were ± 0.758° in PA and ± 0.158" in separation.


Astronomical Association of Queensland 2016 Results: Bluestar Observatory Measurement ...

SYSTEM

Last listed measure New measure

COMMENTS

PA° Sep" Epoch PA° Sep" Epoch*

ARA1961 71 5.9 1921 231.19 18.15 2016.849 Very large movement

B 32 226 4.9 1954 225.77 5.18 2016.833 Slight increase in PA only

I 1142 41 3.7 1933 39.86 3.73 2016.843 Minor reduction in PA

HU 18 250 4.3 1919 251.39 4.29 2016.857 Slight change in PA only

RSS 73 98 10.7 1976 150.43 34.14 2017.019 Large movement over 41 years

RST2355 351 5.8 1949 351.41 6.06 2017.019 Minor change in both axes

I 554AB 183 3.2 1933 184.76 4.01 2016.513 Slight increases since 1933

I 554AC 159 5.6 1972 154.07 5.76 2016.513 Movement in PA only

RST 814 113 4.5 1967 114.16 4.97 2016.476 Small change since first measure

CPO 460 27 7.4 1902 29.80 6.53 2016.506 Movement evident

LDS 696 116 31.7 1999 115.84 31.60 2016.616 Slight decrease in PA

HDO 156AB 89 6.4 2010 88.69 6.60 2016.605 Possible slight changes

HDO 156AC 54 8.4 1999 53.66 8.29 2016.605 Possible slight changes

HO 277 68 3.6 1939 67.53 3.01 2016.627 Little probable change

I 1047AB 331 9.6 1912 330.97 6.20 2016.556 Definite decrease in separation

RSS 568 50 10.6 1974 53.77 9.72 2016.702 Clear changes evident

CPO 632 1 3.0 1901 0.66 3.58 2016.706 Little probable change

CPO 97 135 4.2 1932 135.47 4.1 2016.702 Little probable change

PRO 240 270 4.7 1910 238.26 35.72 2016.764 Considerable movement

DAW 28AB 74 3.8 1933 76.39 3.63 2016.764 Clear change in PA only

Table 1



ARA1961

Cetus

RA. 01 09.2 DEC. -22 39 Last Measure

1921

MAG. 11.78 &

12.7 PA. 71° SEP. 5.9"

Date No. images PA° Sep"

24 Oct 2016 10 231.38 18.170

01 Nov 2016 10 231.76 18.241

04 Nov 2016 10 231.28 18.108

05 Nov 2016 10 231.13 18.202

06 Nov 2016 10 230.99 18.050

07 Nov 2016 10 230.86 18.125

18 Nov 2016 10 230.95 18.154

Mean 231.193 18.150

Std dev 0.311 0.063

95% CI +/- 0.287 0.058

P(t) movement 0.00 0.00

COMMENTS

Large movement. Only one other possible secondary candi-

date even further away in SE quadrant. North at bottom,

east to the right.

B32

Fornax


1954

MAG. 9.6 &

13.3 PA. 226° SEP. 4.9"


15 Oct 2016 10 225.82 5.144

29 Oct 2016 10 225.97 5.160

01 Nov 2016 10 225.67 4.957

04 Nov 2016 10 225.13 5.304

05 Nov 2016 10 224.98 5.392

07 Nov 2016 10 227.22 4.999

18 Nov 2016 10 225.61 5.286

Mean 225.771 5.177

Std dev 0.732 0.161

95% CI +/- 0.677 0.149


COMMENTS

No change in PA since first measurement in 1926. Slight

increase in separation consistent with the two previous

recordings.

I 1142

Eridanus


1933

MAG. 9.65 &

12.6 PA. 41° SEP. 3.7"


15 Oct 2016 10 40.99 3.609

29 Oct 2016 10 39.59 3.858

05 Nov 2016 10 38.98 3.949

06 Nov 2016 10 40.66 3.872

07 Nov 2016 10 38.97 3.758

20 Nov 2016 10 40.61 3.507

22 Nov 2016 10 39.20 3.568

Mean 39.857 3.732

Std dev 0.871 0.171

95% CI +/- 0.806 0.158


COMMENTS

Minor reduction in PA consistent with the two previous

measurements. No change in separation over the same pe-

riod.

HU18

Cetus


1919

MAG. 8.77 &

12.8 PA. 250.0° SEP. 4.3"


29 Oct 2016 10 251.34 4.257

04 Nov 2016 10 250.81 4.445

05 Nov 2016 10 ….. …..

06 Nov 2016 10 251.08 4.220

07 Nov 2016 10 251.98 4.165

18 Nov 2016 10 252.13 4.333

20 Nov 2016 10 251.01 4.302

Mean 251.392 4.287

Std dev 0.543 0.098

95% CI +/- 0.570 0.102


COMMENTS

Slight change in PA since first measurement in 1900.

Poor quality images obtained 05 Nov 2016 not used for

reduction.

RSS73

Caelum


1976

MAG. 8.67 &

PA. 98° SEP. 10.7"


25 Nov 2016 10 150.28 34.061

27 Dec 2016 10 150.51 34.220

28 Dec 2016 10 150.28 34.159

30 Dec 2016 10 150.43 34.182

09 Jan 2017 10 150.43 34.099

10 Jan 2017 10 150.51 34.151

23 Jan 2017 10 150.55 34.082

Mean 150.427 34.136

Std dev 0.110 0.057

95% CI +/- 0.101 0.053


COMMENTS

Large movement over a period of 41 years.

RST2355

Pictor

RA. 04 41.7 DEC. -48.09 Last Measure

1949

MAG. 8.67 &

14.9 PA. 351° SEP. 5.8"


25 Nov 2016 10 352.14 5.965

27 Dec 2016 10 351.72 6.051

28 Dec 2016 10 351.71 6.058

30 Dec 2016 10 351.83 6.168

09 Jan 2017 10 351.49 6.115

10 Jan 2017 10 349.97 6.119

23 Jan 2017 10 351.00 5.932

Mean 351.409 6.058

Standard deviation 0.724 0.085

95% CI +/- 0.669 0.079


COMMENTS

Minor movement in both axes consistent with changes

since the first measure in 1936.

Vol. 15 No. 3 July 1, 2019 24 Journal of Double Star Observations


I 554AC

Norma


1972

MAG. 8.17 &

11.4 PA. 159° SEP. 5.6"


14 June 2016 10 154.69 5.787

28 June 2016 10 154.12 5.835

09 July 2016 10 153.20 5.947

23 July 2016 10 151.64 5.426

27 July 2016 10 155.43 5.922

29 July 2016 10 153.81 5.688

30 July 2016 10 155.59 5.708

Mean 154.069 5.759


95% CI +/- 1.268 0.163


COMMENTS

Movement evident in PA only.

I 554AB

Norma


1933

MAG. 8.17 &

11.4 PA. 183° SEP.3.2"


14 June 2016 10 183.45 4.137

28 June 2016 10 187.39 4.073

09 July 2016 10 187.42 3.969

23 July 2016 10 183.02 3.101

27 July 2016 10 192.27 8.368

29 July 2016 10 182.51 4.787

30 July 2016 10 190.48 3.887

Mean 184.758 4.013


95% CI +/- 3.029 0.748


COMMENTS

Very slight increases possible since 1933. Reduction

measures of 27 July and 30 July 2016 excluded from final

calculation due to poor quality images.

RST814

Norma


1967

MAG. 7.65 &

13.4 PA. 113° SEP. 4.5"


20 May 2016 10 113.82 5.111

07 June 2016 10 114.39 4.985

08 June 2016 10 113.89 4.936

28 June 2016 10 114.50 5.009

23 July 2016 10 113.63 4.765

27 July 2016 10 114.76 5.008

28 July 2016 10 116.77 4.379

Mean 114.165 4.969


95% CI +/- 0.469 0.121


COMMENTS

Consistent with very small changes since the first 1929

measure. Reduction measure of 28 July 2016 excluded from

final calculation due to poor quality images.

CPO460

Norma


1902

MAG. 9.16 &

14.6 PA. 27° SEP. 7.4"


08 June 2016 10 29.56 6.534

14 June 2016 10 29.56 6.393

28 June 2016 10 29.53 6.486

09 July 2016 10 30.12 6.607

27 July 2016 10 29.36 6.626

30 July 2016 10 30.63 6.531

31 July 2016 10 29.87 6.503

Mean 29.804 6.526


95% CI +/- 0.410 0.072


COMMENTS

Movement evident since the only previous measure in

1902.

LDS696

Pavo


1999

MAG. 11.5 &

14.2 PA. 116° SEP. 31.7"


05 August 2016 10 115.89 31.65

06 August 2016 10 115.79 31.622

08 August 2016 10 115.85 31.67

12 August 2016 10 115.94 31.512

15 August 2016 10 115.77 31.604

20 August 2016 10 115.8 31.554

21 August 2016 10 115.85 31.606

Mean 115.841 31.603

Standard devia-

tion 0.060 0.054

95% CI +/- 0.056 0.050


COMMENTS

Slight decrease in PA over the previous measure in 1999

would seem to be consistent with change since the first

1920 measurement. Little apparent change in separation.

HDO156AB

Capricorn


2010

MAG. 7.89 &

10.3 PA.89° SEP. 6.4"


30 July 2016 10 89.03 6.612

01 August 2016 10 89.23 6.623

06 August 2016 10 88.63 6.543

08 August 2016 10 88.84 6.588

12 August 2016 10 88.11 6.635

15 August 2016 10 88.72 6.577

20 August 2016 10 88.25 6.629

Mean 88.687 6.601


95% CI +/- 0.371 0.031


COMMENTS

Possible slight change in both axes since last recent

measurement.



HDO156AC

Capricorn


1999

MAG. 7.89 &

12.8 PA. 54° SEP. 8.4"


30 July 2016 10 54.05 8.212

01 August 2016 10 54.05 8.315

06 August 2016 10 53.35 8.222

08 August 2016 10 53.26 8.302

12 August 2016 10 53.96 8.319

15 August 2016 10 53.49 8.312

20 August 2016 10 53.48 8.354

Mean 53.663 8.291


95% CI +/- 0.318 0.049


COMMENTS

Possible very minor change in both axes since last re-

cent measurement.

HO277

Aquila


1939

MAG. 8.91 &

13.3 PA. 68° SEP. 3.6"


30 July 2016 10 68.26 2.965

06 August 2016 10 66.27 3.094

12 August 2016 10 66.02 3.191

20 August 2016 10 70.38 3.029

27 August 2016 10 67.79 2.909

03 September 2016 10 68.39 2.985

05 September 2016 10 65.61 2.88

Mean 67.531 3.008

Standard devia-

tion 1.684 0.108

95% CI +/- 1.558 0.100


COMMENTS

Little probable movement.

I 1047AB

Pavo


1912

MAG. 8.21 &

12.6 PA. 331° SEP. 9.6"


09 July 2016 10 331.69 6.439

23 July 2016 10 330.39 6.230

27 July 2016 10 331.53 6.126

28 July 2016 10 329.90 6.088

30 July 2016 10 330.08 6.060

01 August 2016 10 331.51 6.317

05 August 2016 10 331.70 6.133

Mean 330.971 6.199

Standard devia-

tion 0.809 0.138

95% CI +/- 0.748 0.127


COMMENTS

Measurable decrease in sep. since the previous two re-

cordings. Little probable movement in PA.

RSS568

Grus


1974

MAG. 8.5 & n/

a PA. 50° SEP. 10.6"


27 August 2016 10 53.8 9.752

28 August 2016 10 53.71 9.824

03 September 2016 10 54.7 9.629

05 September 2016 10 53.06 9.71

13 September 2016 10 54.12 9.771

30 September 2016 10 53.51 9.78

01 October 2018 10 53.48 9.612

Mean 53.769 9.725

Standard devia-

tion 0.524 0.079

95% CI +/- 0.485 0.073


COMMENTS

Clear movement on both axes since the initial measure in

1974.

CPO632

Grus


1901

MAG. 10.9 &

12.6 PA. 1° SEP. 3.0"


27 August 2016 10 1.06 3.525

28 August 2016 10 0.87 3.623

03 September 2016 10 0.23 3.588

05 September 2016 10 -0.13 3.693

30 September 2016 10 0.23 3.532

01 October 2016 10 0.98 3.636

04 October 2016 10 1.35 3.489

Mean 0.656 3.584

Standard devia-

tion 0.544 0.072

95% CI +/- 0.503 0.067


COMMENTS

Little probable movement since 1901.

CPO97

Grus

RA. 23 10.4 DEC. -46 53 Last Meas-

ure 1932

MAG. 9.82 &

13.0 PA. 135° SEP. 4.2"


27 August 2016 10 135.52 4.161

28 August 2016 10 135.86 4.065

03 September 2016 10 136.55 4.083

05 September 2016 10 136.91 4.059

13 September 2016 10 136.16 4.113

30 September 2016 10 133.29 4.084

01 October 2016 10 133.99 4.107

Mean 135.469 4.096

Standard devia-

tion 1.342 0.035

95% CI +/- 1.242 0.032


COMMENTS

Little probable movement since last measurement.



PRO240

Sculptor


1910

MAG. 10.0 &

10.3 PA. 270° SEP. 4.7"


01 October 2016 10 238.19 35.695

04 October 2016 10 238.24 35.743

05 October 2016 10 238.30 35.665

06 October 2016 10 238.28 35.769

07 October 2016 10 238.33 35.815

10 October 2016 10 238.19 35.672

12 October 2016 10 238.27 35.702

Mean 238.257 35.723


95% CI +/- 0.049 0.051


COMMENTS

Considerable change in both axes over 106 years.

DAW28AB

Phoenix


1933

MAG. 6.65 &

11.1 PA. 74° SEP. 3.8"


01 October 2016 10 74.66 3.493

04 October 2016 10 77.79 3.676

07 October 2016 10 76.3 3.706

10 October 2016 10 75.37 3.816

12 October 2016 10 77.81 3.461

Mean 76.386 3.630


95% CI +/- 1.758 0.186


COMMENTS

Two nights poor quality data not used. Clear change evi-

dent in PA only.



References

Losse, F. Reduc software, V4.5.1.

http://www.astrosurf.com/hfosaf/uk/tdownload.htm

Napier-Munn, T.J. and Jenkinson, G., 2009, “Measurement of some neglected southern multiple stars in Pavo”, Webb Society Double Star Section Circular, 17, 6-12.

Napier-Munn, T.J and Jenkinson G., 2014, “Analysis of Errors in the Measurement of Double Stars Using Imaging and the Reduc Software”, Journal of Dou-ble Star Observations, 10(3), 193-198.

Argyle, R.W., 2012, Observing and Measuring Visual Double Stars, 2nd edition, Springer.

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http://www.astrosurf.com/hfosaf/uk/tdownload.htm

Journal of Double Star Observations V5, No4

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