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Nicholson, M. (2007). SOLAR COMPANIONS WITHIN 33 PARSECS. PHILICA.COM Article number 77.

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SOLAR COMPANIONS WITHIN 33 PARSECS

Martin Nicholsonconfirmed user (Independent Researcher)

Published in astro.philica.com

Abstract
Details of 55 stars extracted from a sub-set of the Sloan Digital Sky Survey (SDSS) database and believed to be lying within 33 parsecs are presented. Some of the stars are believed to be new discoveries.

Article body

 

SOLAR COMPANIONS WITHIN 33 PARSECS

Martin Nicholson, Daventry, England

martin_piers_nicholson@yahoo.co.uk

http://www.martin-nicholson.info

Abstract - Details of 55 stars, extracted from a sub-set of the Sloan Digital Sky Survey (SDSS) database, and believed to be lying within 33 parsecs are presented. Some of the stars are believed to be new discoveries.

For a nearby star to have been undetected in previous surveys it would need to be faint.  The most likely candidate for a close, faint star is a red dwarf. Red dwarfs are the most frequently occurring stars in the galaxy and are normally regarded as having between eight percent and the half of the mass of the Sun. They appear red in colour due to their low surface temperature of 2500 - 4000 Kelvin.

An excellent summary of the characteristics of the closest stars can be found at :

http://en.wikipedia.org/wiki/List_of_nearest_stars

In the initial trial SDSS stars had to meet two criteria r - i > 1.57 and i - z > 0.87. A total of 55 stars were found to lie within 33 parsecs and these are summarised below.

TABLE 1 - SUMMARY OF RESULTS

  

 

 ABSOLUTE

 DISTANCE

 SOLAR

#

RA

DECL

MAGNITUDE (MV)

PARSEC

MASSES

1

14.47195934

-10.46690034

15.201

31.011

0.120

2

17.88091426

-11.00431445

14.059

30.587

0.157

3

21.13021174

-0.465645765

16.221

26.344

0.102

4

21.42448147

13.656196

14.998

29.461

0.125

5

22.9010284

-0.966715422

14.889

31.476

0.128

6

42.51016675

-8.144844108

15.866

25.451

0.107

7

45.10771052

-7.781895662

14.487

32.002

0.141

8

48.10469516

0.36621008

15.893

29.910

0.106

9

57.75011587

-0.879411637

17.177

14.780

0.095

10

116.7350117

43.07108563

14.782

26.124

0.131

11

127.0297194

42.28269941

14.372

31.248

0.145

12

134.645169

7.981858577

15.150

26.836

0.121

13

134.6803269

-0.696280486

15.560

25.443

0.112

14

136.1286702

52.45877604

14.182

32.443

0.152

15

139.7067149

63.25293578

15.269

20.701

0.118

16

146.8336344

-0.335976969

16.175

28.488

0.102

17

147.9643534

23.18799075

14.306

27.404

0.147

18

150.9418342

51.91334565

14.645

31.057

0.135

19

158.223693

55.63125123

14.512

30.258

0.140

20

164.2655509

22.28876605

14.182

28.104

0.152

21

166.3896725

32.23144702

14.878

25.547

0.128

22

166.5789532

4.4758552

17.776

20.829

0.097

23

170.8723054

1.9011343

17.472

22.621

0.096

24

172.0292514

1.691806265

14.507

29.494

0.140

25

173.5655156

20.78176406

15.063

29.561

0.123

26

176.0929101

45.2953862

17.553

20.271

0.096

27

179.9958562

21.08382066

15.001

24.982

0.125

28

180.7064161

42.07958789

16.307

32.797

0.101

29

181.2866466

48.47180328

15.201

27.501

0.120

30

182.2412286

55.56371045

14.898

29.034

0.128

31

183.2141925

11.43214769

14.276

31.123

0.148

32

189.944561

4.179626779

15.483

19.142

0.114

33

190.6223588

-1.990004186

13.982

32.898

0.160

34

195.3207578

41.21123614

14.865

28.654

0.129

35

196.0983342

50.08817905

14.760

29.113

0.132

36

196.8708457

33.41897298

14.421

28.526

0.143

37

200.9234202

7.801255847

14.777

26.675

0.131

38

201.8789367

1.827338199

17.354

24.176

0.096

39

205.9114457

8.428850619

15.999

28.692

0.105

40

207.0892087

4.259004987

15.822

26.077

0.107

41

209.2403356

27.51681646

14.931

23.357

0.127

42

209.2499286

6.250661879

14.978

31.085

0.126

43

216.3943535

25.66803356

16.140

16.730

0.103

44

223.9568131

3.361549342

14.533

31.860

0.139

45

225.1097811

-0.657756954

15.540

24.100

0.112

46

229.4056863

4.880855847

15.291

27.570

0.118

47

238.106634

25.91625289

14.840

28.904

0.129

48

244.1317416

7.432489618

15.745

23.236

0.109

49

251.1290506

12.67620407

15.470

30.506

0.114

50

251.774023

41.28529863

16.094

27.495

0.103

51

258.5363211

60.79164375

15.300

26.161

0.118

52

332.7331194

-9.600400621

14.670

28.116

0.135

53

339.4009972

12.96307156

14.179

31.230

0.152

54

340.8288987

-9.461525852

14.248

30.531

0.149

55

351.6091748

-9.866133968

14.258

31.286

0.149


Full details of the methodology used can be obtained from the author.

Conclusions

The chosen method - sampling the SDSS for red dwarfs - has generated a number of promising candidates for stars within 33 parsecs. The survey will now be extended to cover the much larger number of stars with an SDSS i band magnitude between 16 and 19.

Acknowledgements

This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation.

Funding for the SDSS-II has been provided by the Alfred P. Sloan Foundation, the National Science Foundation, the U.S. Department of Energy, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council for England.

The SDSS is managed by the Astrophysical Research Consortium for the Participating Institutions: the American Museum of Natural History, Astrophysical Institute Potsdam, University of Basel, Cambridge University, Case Western Reserve University, University of Chicago, Drexel University, Fermilab, the Institute for Advanced Study, the Japan Participation Group, Johns Hopkins University, the Joint Institute for Nuclear Astrophysics, the Kavli Institute for Particle Astrophysics and Cosmology, the Korean Scientist Group, the Chinese Academy of Sciences (LAMOST), Los Alamos National Laboratory, the Max-Planck-Institute for Astronomy (MPA), the Max-Planck-Institute for Astrophysics (MPIA), New Mexico State University, Ohio State University, University of Pittsburgh, University of Portsmouth, Princeton University, the United States Naval Observatory, and the University of Washington.

The author also made use of the following on-line resources :-

The Astrophysics Data System (ADS) http://adswww.harvard.edu/index.html

The Vizier catalogue service http://vizier.u-strasbg.fr/

Lupton, R., 2005, Transformations between SDSS magnitudes and UBVRcIc, http://www.sdss.org/dr4/algorithms/sdssUBVRITransform.html#Lupton2005

References

Delfosse, X.; Forveille, T.; Ségransan, D.; Beuzit, J.-L.; Udry, S.; Perrier, C.; Mayor, M., 2000, Accurate masses of very low mass stars. IV. Improved mass-luminosity relations, Astronomy and Astrophysics, v.364, 217-224.

Suzanne L. Hawley, Kevin R. Covey, Gillian R. Knap et al, 2002, Characterization of M, L and T Dwarfs in the Sloan Digital Sky Survey, The Astronomical Journal, Volume 123, Issue 6, pp. 3409-3427

Lepine, Sebastien, 2005, Nearby Stars from the LSPM-North Proper-Motion Catalog. I. Main-Sequence Dwarfs and Giants within 33 Parsecs of the Sun, The Astronomical Journal, Volume 130, Issue 4, pp. 1680-1692.

Information about this Article
Peer-review ratings (from 1 review, where a score of 100 represents the ‘average’ level):
Originality = 225.00, importance = 225.00, overall quality = 25.00
This Article was published on 27th January, 2007 at 11:54:05 and has been viewed 4367 times.

Creative Commons License
This work is licensed under a Creative Commons Attribution 2.5 License.
The full citation for this Article is:
Nicholson, M. (2007). SOLAR COMPANIONS WITHIN 33 PARSECS. PHILICA.COM Article number 77.


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1 Peer review [reviewer #10906confirmed user] added 10th November, 2009 at 04:35:12

“Methodology available from the author”, it says. But one can reconstruct how it would have to be done. The SDSS gives brightnesses in three bands, and everything would be derived from those using a model. Based on this, it is very misleading to use such accuracies for distance and mass. Either could be off by 10%, possibly more.

While I’m at it, the RA and Dec data also has too much accuracy.

—-David Hobby

Originality: 6, Importance: 6, Overall quality: 2




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