Publications of the Astronomical Society of the Pacific

Trimble, Virginia; Aschwanden, Markus J.

doi: 10.1086/341673pmid: N/A

During the year, astronomers provided explanations for solar topics ranging from the multiple personality disorder of neutrinos to cannibalism of CMEs (coronal mass ejections) and extra‐solar topics including quivering stars, out‐of‐phase gaseous media, black holes of all sizes (too large, too small, and too medium), and the existence of the universe. Some of these explanations are probably possibly true, though the authors are not betting large sums on any one. The data ought to remain true forever, though this requires a careful definition of “data” (think of the Martian canals).

Fischer, Debra A.; Marcy, Geoffrey W.; Butler, R. Paul; Vogt, Steven S.; Walp, Bernie; Apps, Kevin

doi: 10.1086/341677pmid: N/A

Precise Doppler observations at Lick Observatory have revealed a substellar companion orbiting the F9 V star HD 136118 with an orbital period P = 1209 ± 24 days, velocity semiamplitude K = 212 ± 6 m s−1, and eccentricity of 0.37 ± 0.025. The assumed stellar mass of 1.24 M⊙ yields a Keplerian companion with Msin i = 11.9 MJ and semimajor axis of 2.3 AU. We also confirm the orbital solutions for two previously announced planets, one orbiting the F8 V star HD 50554 and one orbiting the G0 V star HD 106252. Our orbital solution for HD 50554 yields P = 1254 ± 34 days, K = 78.5 ± 6.7 m s−1, and e = 0.51 ± 0.06. The assumed stellar mass of 1.065 M⊙ implies a companion mass Msin i = 3.7 MJ and semimajor axis of 2.2 AU. For HD 106252, we find P = 1503.3 ± 62 days, K = 150.9 ± 25 m s−1, and eccentricity e = 0.57 ± 0.11. The assumed stellar mass of 0.96 M⊙ implies Msin i = 6.96 MJ and semimajor axis of 2.42 AU.

Gray, David F.; Scott, Heather R.; Postma, Joseph E.

doi: 10.1086/341675pmid: N/A

The fraction of light removed from a star’s spectrum by the spectral lines, the line absorption, is shown to be a precise empirical indicator of metallicity. We measured the line absorption in 89 class III giant stars in a 42.5 Å window between 6219.0 and 6261.5 Å and then calibrated these values against published metallicities. We show that the line absorption can be measured precisely enough to improve the metallicity precision about fivefold over the original calibration metallicities, reaching a precision of 0.01 dex in favorable cases.

Lee, Kevin M.; Schmidt, Edward G.; Langan, Shawn T.

doi: 10.1086/341679pmid: N/A

We have obtained 462 new V and R observations of the RR Lyrae star GV Andromedae. Our data set is consistent with a primary period of 0.528092 days; however, the light curve of GV And cannot be well described by a single period. We conclude that GV And demonstrates the Blazhko effect with a Blazhko period of approximately 32 days.

Percy, John R.; Hosick, JoAnne; Kincaide, Heather; Pang, Ceci

doi: 10.1086/341680pmid: N/A

We have used Hipparcos epoch photometry and a form of autocorrelation analysis to investigate the amplitude and timescale of the short‐period variability of 82 Be stars, including 46 Be stars that were analyzed by Hubert & Floquet using Fourier and CLEAN analysis and 36 other Be stars that were suspected of short‐period variability. Our method has given useful information for about 84% of these stars; for the rest, the time distribution of the Hipparcos epoch photometry limits the capability of our technique.

Abt, Helmut A.

doi: 10.1086/341676pmid: N/A

Wilson showed that G8–M1 dwarfs have a range of 0.30 mag in P−V color whereas the color range for earlier stars is 0.12 mag. He attributed the increased range for the later stars to differing hydrogen‐to‐metal ratios in the temperature region where most of the electrons come from the metals. I explored those stars using Hipparcos parallaxes and photometry and with MK types. His effect can be explained without resorting to abundance differences, which are not confirmed elsewhere, by poorer spectral classification from unwidened spectra for the fainter stars and the use of maximum color ranges, rather than dispersions. I also considered, with negative results, the possibility that the Ca ii H and K emission lines or chromospheric activity could cause the large ranges in colors. Different amounts of chromospheric activity do not affect the colors significantly.

Clénet, Y.; Le Coarer, E.; Joncas, G.; Beuzit, J.‐L.; Rouan, D.; Chalabaev, A.; Rabou, P.; Arsenault, R.; Delage, C.; Marlot, C.; Vallée, P.; Grundseth, B.; Thomas, J.; Forveille, T.; Lai, O.; Lacombe, F.

Kannappan, Sheila J.; Fabricant, Daniel G.; Hughes, Charles B.

doi: 10.1086/341678pmid: N/A

We discuss the design of an inexpensive, high‐throughput CCD spectrograph for a small telescope. By using optical fibers to carry the light from the telescope focus to a tabletop spectrograph, one can minimize the weight carried by the telescope and simplify the spectrograph design. We recently employed this approach in the construction of IntroSpec, an instrument built for the 16 inch Knowles Telescope on the Harvard College campus.