Speckle Interferometry of Eleven Hipparcos Binary Discoveries

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1 Page 122 Speckle Interferometry of Eleven Hipparcos Binary Discoveries Matthew Kehrli, Heather David, Evan Drake, Corina Gonzalez, Joe Zuchegno, and Russell Genet California Polytechnic State University San Luis Obispo, California Abstract: The 11 Hipparcos-discovered binaries studied in this paper were observed at Kitt Peak National Observatory during an eight-night run from October 16th-23rd, 2013 using an EMCCD camera attached to the 2.1-meter telescope. PlateSolve 3.44, a speckle reduction program, was utilized to reduce the observations and create autocorrelograms of the 11 binaries. Each autocorrelogram provided data on the position angle and separation between the stars. Accuracy of the results was measured by determining the mean, standard deviation, and standard error for the difference between the predicted and reduced results for both the position angle and separation. For, this calculation resulted in a mean of 1.65, standard deviation of 1.64, and a mean standard error of ±0.50. For ρ, it resulted in a mean of , standard deviation of , and a mean standard error of ± Introduction The Hipparcos mission was designed to determine stellar distances to facilitate stellar internal composition, ages, and the history of their nuclear-fuel burning (Perryman 2010). During its time in orbit, Hipparcos observed over 100,000 stars, of which approximately 12,000 were double stars and 3,406 were newly discovered doubles (Mason et al. 1999). Hipparcos took measurements on position, parallax and proper motion. Stars with similar values for position and parallax, or double stars, underwent further observation to determine whether they were physically associated, rather than just chance alignments (Perryman 2010). In the Fall of 2013, a group of students and their mentors made speckle interferometry observations on some of the Hipparcos-discovered binaries at Kitt Peak National Observatory (Genet et al. 2015b). Hipparcos double star discoveries were selected from over one thousand Kitt Peak double star observations. Binaries lacking published orbits were eliminated after consulting the Sixth Catalog of Orbits of Visual Binary Stars (Hartkopf 2016). This left 12 binaries, one of which served in a pilot project described in a previous article in this issue of the Journal of Double Star Observations (Kehrli et al. 2016). The current study contributes new position angles and separations for the remaining 11 Hipparcos binary discoveries observed at Kitt Peak National Observatory. Instrumentation, Observations, Calibration, and Reduction This paper follows a previous paper studying one Hipparcos-discovered binary, HIP 4849, observed at Kitt Peak National Observatory. An expanded summary of the instrumentation, observations, calibration, and reduction is provided in the pilot paper (Kehrli et al. 2016). Instrumentation The observations were made with the Kitt Peak National Observatory s 2.1-Meter Telescope from October 16-23, The telescope did not include a camera for speckle interferometry observations, so the observers supplied their own (Genet 2013). The speckle camera system employed an Andor Luca R EMCCD, which has 10 μ square pixels in a 658x496 pixel array (Genet et al. 2015d). The portable EMCCD camera system increased the signal to a level where the high speed read noise is insignificant, with a read noise well under one electron RMS (Genet et al. 2015a). With a magnification of 8x, the Andor Luca R EMCCD provided an overall effective focal length of

2 Page 123 about 129,600mm and F/ratio of 61.7 when attached to the 2.1-Meter telescope (Genet et al. 2015b). Observations The observers were granted eight nights of observing time at Kitt Peak National Observatory. The observing conditions were completely clear each night, except for the last half of the eighth night (Genet 2015c). The eight-night run allowed for speckle observations of over 1,000 close double stars, many of which were binaries. Calibration As previously mentioned, the observations were calibrated with data collected from multiple observations of six binaries with previously published orbits. A comparison of these Kitt Peak observations with the published orbits allowed the camera angle, from true north, and plate scale, /pixel, to be determined (Wallace 2015). Overall internal precision for the run was found to be and , and overall accuracy was determined to be and These values were obtained using statistical analysis of five calibration binaries made throughout the run (Wallace 2015). Reduction The PlateSolve 3.44 program, developed by David Rowe, was used to reduce observations of the 11 binaries. It also served to create autocorrelograms, such as the one seen in Figure 1, which depicts WDS The autocorrelogram for each binary provided data on the position angle and separation between the stars. In order to include the maximum amount of Figure 1. Autocorrelogram of WDS useful data and exclude most unwanted noise, the Gaussian Lowpass was set to a 30-pixel radius and the Gaussian Highpass was set to a 3-pixel radius. Results Each observation was reduced six times using PlateSolve The center of the target star was selected manually to find the angle,, and separation,. These six and ρ values were used to derive the mean values for the binary, and were compared to the predicted values in Table 1. Table 1. Position Angle and Separation Figure # Star Identifier Date (JD) Mean Pred. o Mean ρ" Pred. ρ" " 2 WDS WDS WDS WDS WDS WDS WDS WDS WDS WDS WDS

Page 124 In Figures 2 to 12, the predicted values for the ρ and of the binaries were determined using a binary calibration Excel spreadsheet (Drummond 2011).

3 Page 124 In Figures 2 to 12, the predicted values for the ρ and of the binaries were determined using a binary calibration Excel spreadsheet (Drummond 2011). These results, provided in Table 1, are labeled Predicted and Predicted ρ. By finding the difference between the mean and predicted values for and ρ, o and " were determined as shown in Table 1. Drummond s spreadsheet solves Kepler s equation for any given date of every binary with a published orbit. The date for each binary was recorded in the spreadsheet. For accuracy to be evaluated, the mean, standard deviation, and standard error were calculated for the difference between the predicted and actual values for both the position angle and separation, degrees and arcseconds. For the separation angle, this calculation resulted in a mean of 1.65 o, standard deviation of 1.64 o, and a standard error of ±0.50 o. For ρ, it resulted in a mean of ", standard deviation of ", and a standard error of ±0.0032". Discussion Figures 2 to 12 plot the results alongside orbital plots provided by Brian Mason from the U.S. Naval Observatory. Microsoft Paint served as a coordinategrid system for the orbital plots from the USNO. Since the scale varied for each plot, the arcsecond-to-pixel ratio was determined separately for each binary. The distance for both x and y coordinate positions was calculated from the angle and distance obtained with PlateSolve After converting these values to pixel coordinates, they were used to plot the binary systems (marked as plus symbols in Figures 2 to 12). By definition, the calculated separation and position angle must fall on the path of the given orbit of the binary provided from the U.S. Naval Observatory (marked as a line intersecting the established orbit in Figures 2 to 12). The new data points, marked on the figures below, provide substantive information that may assist in confirming, refining, or modifying the published orbits. (Continued on page 130) Figure 2. Orbit of Binary Star System WDS Observed on Sunday, October 20, 2013

4 Page 125 Figure 3. Orbit of Binary Star System WDS Observed on Friday, October 18, 2013 Figure 4. Orbit of Binary Star System WDS Observed on Tuesday, October 22, 2013

5 Page 126 Figure 5. Orbit of Binary Star System WDS Observed on Saturday, October 19, 2013 Figure 6. Orbit of Binary Star System WDS Observed on Friday, October 18, 2013

Observed on Monday, October 21, 2013. Figure 8.

6 Page 127 Figure 7. Orbit of Binary Star System WDS Observed on Monday, October 21, Figure 8. Orbit of Binary Star System WDS Observed on Monday, October 21, 2013.

7 Page 128 Figure 9. Orbit of Binary Star System WDS Observed on Saturday, October 19, Figure 10. Orbit of Binary Star System WDS Observed on Tuesday, October 22, 2013.

Observed on Tuesday, October 22, 2013. Figure 12.

8 Page 129 Figure 11. Orbit of Binary Star System WDS Observed on Tuesday, October 22, Figure 12. Orbit of Binary Star System WDS Observed on Monday, October 21, 2013.

9 Page 130 (Continued from page 124) Conclusion By analyzing 11 of the binaries observed at the Kitt Peak National Observatory, the study accomplished the goal of contributing position angles and separations to their apparent orbits. Further analysis on the data may serve to refine orbital predictions. Acknowledgements We are grateful to Kitt Peak National Observatory for the use of the 2.1-meter telescope, and also to the team which conducted the observations in The speckle interferometry camera was obtained through funds from the American Astronomical Society s Small Research Grants. We thank David Rowe for the use of the PlateSolve 3.44 Speckle Reduction Tool. This research made use of the Washington Double Star Catalog maintained at the U.S. Naval Observatory. We thank Jack Drummond for providing his binary calibration spreadsheet. Furthermore, we are grateful for the reviews of the paper given by Robert Buccheim, Richard Harshaw, and Vera Wallen. A special thanks to William and Linda Frost for providing funding to the Frost Undergraduate Summer Research Program at California Polytechnic State University, San Luis Obispo, California. References Drummond, J., 2011, "Calibration Binaries", Proceedings of the Advanced Maui Optical and Space Surveillance Technologies Conference, S. Ryan (Ed.), Wailea, Maui, Hawaii. Genet, R. M., 2013, "Portable Speckle Interferometry Camera System", Journal of Astronomical Instrumentation 2, 2. Genet, R., Rowe, D., Smith, T. C., Teiche, A., Harshaw, R., Wallace, D., Weise, E., Wiley, E., Boyce, G., Boyce, P., Brantson, D., Chaney, K., Clark, K., R., Estrada, C., Frey, T., Estrada, R., Wayne, G., Huarberg, N., Kenney, J., Jones, G., Loftin, S., McGieson, I., Patel, R., Plummer, J., Ridgely, J., Trueblood, M., Westergren, D., Wren, P., 2015a, "Kitt Peak Speckle Interferometry of Close Visual Binary Stars", Journal of Double Star Observations, 11, 1S. Genet, R. M., Smith, T. C., Clark, R. K., Wren, P., Mathis, H., Summers, D., Hansey, B., 2015b, "Portable Interferometry Camera Checkout at Kitt Peak",, 11, Genet, R. M., 2015c, "Speckle Interferometry of Close Visual Binaries", Journal of Double Star Observation 11, Genet, R. Zirm, H., Francisco, R., Richards, J., Rowe, D., Gray, D., 2015d, "Two New Triple Star Systems with Detectable Inner Orbital Motions", Journal of Double Star Observations, 11, Hartkopf, W., Mason, B., 2016, April 25, "Sixth Catalog of Interferometric Measurements of Binary Stars". Kehrli, M., David, H., Drake, E., Gonzalez, C., Zuchegno, J., Genet, R. M., 2016, "Speckle Interferometry of Binary Star HIP 4898", Journal of Double Star Observations, 13, (this issue). Perryman, M., 2010, The Making of History s Greatest Star Map, New York, Springer. Wycoff, G. L., Brummelaar, T. T., Franz, O. G., 1999, "Speckle Interferometry of New and Problem Hipparcos Binaries", The Astronomical Journal, 117, 4. Wallace, D., 2015, An Investigation of Six Poorly Described Close Visual Double Stars Using Speckle Interferometry, Master s Thesis, Dept of Space Science, University of North Dakota, Grand Forks.

First Speckle Interferometry Observation of Binary BU 1292

First Speckle Interferometry Observation of Binary BU 1292 Meryl Adam 1, Stephanie Roberts 2, Miriam Schenk 3, Carmen VanRonk 3, Tara Loayza 3, Russell Genet 2,4,5, Bobby Johnson 3, Thomas C. Smith 6,