Annual Report 1999

Astronomy at the University of Canterbury Department of Physics and Astronomy and Mt John University Observatory — annual report 1999

Director: Prof. J.B. Hearnshaw

Report for the period 1 January 1999 to 31 December 1999

1 Staﬀ

Assoc. Prof. Peter Cottrell continued as Head of Department in 1999, Prof. John Hearn- shaw continued as Mt John director and Alan Gilmore as Mt John superintendent. Cottrell continued to serve on the Carter Observatory board as deputy chair in 1999, and on the organizing committees of IAU Commissions 27 (variable stars) and 29 (stellar spectra). He was also elected to the council of the Astronomical Society of Australia in July. Dr William Tobin continued on a half-time lectureship in 1999, working the ﬁrst six months of the year in Christchurch and the remainder in France. Dr Karen Pollard was appointed to a temporary lectureship in astronomy for the second half of the year. Dr John Pritchard continued as a Marsden-ﬁnanced postdoctoral fellow until October when he left to take up a New Zealand-funded fellowship at the Niels Bohr Institute of Astronomy in Copenhagen. Other post-doctoral fellows were Michael Albrow (supported by the Marsden Fund), Karen Pollard (New Zealand Foundation for Research, Science and Technology Postdoctoral Fellow) and Ian Bond (the last being based at Mt John on a Marsden-funded fellowship with the MOA project). Stephen Barlow was promoted to technician grade 3. Hearnshaw continued as president of IAU Commission 30 (radial velocities) and Prof. Jack Baggaley as president of IAU Commission 22 (meteors and interplane- tary dust) during the year. Hearnshaw also served on the board of IAU Div. IX (optical techniques), on the IAU Working Group for the world-wide development of astronomy, and he served on the council of the Royal Astron. Soc. of N.Z. as fellows’ representative.

2 Students

In March, Stuart Barnes completed his MSc research with the support of the Mars- den Fund (supervisor Tobin) on the H and K lines of β Pictoris and 51 Ophiuchi and was awarded an MSc with ﬁrst class honours. He then commenced a PhD working on the Hercules spectrograph project (supervisor Hearnshaw) with the support

1 of a University of Canterbury doctoral scholarship. At the end of the year, two students submitted PhD theses: they were Lyndon Watson (supervisor Hearnshaw) with a thesis on active-chromosphere stars with EUV emission, and Jovan Skuljan (supervisors Hearnshaw and Cottrell) on moving groups of stars in the Galaxy. In mid-1999 Daniel Pooley (supervisors Cottrell, Albrow, Pollard) took leave from his PhD research on AGB stars for the remainder of the year and travelled to Europe. The following students have continued their PhD research during the year: Ljil- jana Skuljan (supervisor Cottrell) on RCB stars; Orlon Petterson on binary cepheid variables (supervisors Cottrell and Albrow); Jennifer McSaveney (supervisors Cot- trell and Pollard) on RV Tauri stars; Glenn Bayne (supervisors Tobin, Bond, Pritchard and Pollard) on eclipsing binary stars in the Magellanic Clouds.

3 Visitors

We had several astronomical visitors in 1999. Dr Frank Fekel, from Tennessee State University, came from late February until mid-April as an Erskine Fellow, and gave lectures to third-year astronomy students on variable stars. In May Drs M. Honma (Tokyo) and Y. Kanya (Kyoto) gave a joint seminar on microlensing and dark mat- ter. In June Dr Bill Sheehan (based temporarily in Timaru) gave an historical talk on the American astronomer E.E. Barnard. Prof. Brian Warner (Cape Town) also came in June and gave seminars on novae and on white dwarfs, neutron stars and black holes (the second talk was a public one arranged by the Canterbury Astronom- ical Society). Dr David Buckley from SAAO (Cape Town), a former MSc graduate of Canterbury, visited in August. Prof. Leon Mestel (Sussex UK) visited and gave a seminar on stellar magnetism in October; Prof. Michael Bessell (A.N.U., Canberra) and Peter Gillingham (AAO, Epping) visited in November as part of the feasibility study for New Zealand joining the Southern African Large Telescope (SALT) project (see under miscellaneous below). Dr Penny Sackett (Groningen, Holland) gave a seminar on microlensing in November. In addition, there have been numerous visitors in November for a meeting of the PLANET group (Drs P. Sackett, Groningen; M. Dominik, Groningen; J. Menzies, SAAO; J.-P. Beaulieu, IAP, Paris; A. Gould, Ohio State Univ.; D. Depoy, Ohio State Univ.; K. Sahu, Space Telescope Science Inst.; A. Williams, Perth Observ.; J. Green- hill, Univ. Tasmania and S. Gaudi, Ohio State Univ.) organized at Canterbury by Karen Pollard and Michael Albrow, and there were also visitors at Mt John during the year for the MOA project (including Prof. Yasushi Muraki, Nagoya Univ. and Dr Mine Takeuti, Tohoku Univ., Japan). Drs Ian Griﬃn (Auckland Observatory, studying near-Earth asteroids), Phil Yock (Auckland Univ., MOA project) and De- nis Sullivan (Victoria Univ. Wellington, Whole-Earth Telescope project) all visited Mt John to make observations in 1999. Dr Denis Sullivan and MSc student Tiri Sullivan (both Victoria Univ. Welling-

2 ton) made three observing runs to Mt John in 1999. All were for photoelectric photometry of pulsating degenerate stars. The visit in April was part of the Whole Earth Telescope (WET) program. In April a team from Imperial College London (Drs Wooder and Rigal) and from the Canterbury Electrical and Electronic Engineering Dept. (Drs R. Lane and P. Bones) undertook Scidar measurements of the atmospheric turbulence height distribution on the 1-metre telescope. Cottrell and Honours student Dane Kent participated in this work and as a result they investigated a possible adaptive optics system for Mt John. The height distribution of turbulence indicated most turbulence at low levels in close proximity to the ground.

4 Conferences

Seven Canterbury astronomers attended the second joint RASNZ/ASA conference and associated astronomy education meeting in Sydney in July (Adams, Barnes, Bayne, Cottrell, Petterson, Pollard, Tobin). Cottrell served as co-chair of the organizing committee for this joint meeting. Tobin presented there an oral paper (with Pritchard, Zainuddin and Bayne) on Magellanic Cloud eclipsing binaries. Tobin, Barnes and Pollard also gave a poster paper on β Pictoris. Pollard gave an oral paper on selected results from the PLANET collaboration at this meeting and Albrow and Pollard presented a poster on variable star research in the PLANET collaboration. Petterson, Cottrell and Albrow had a poster paper on cepheids and Cottrell gave an oral presentation on New Zealand participation in SALT at a session on future options for Australasian optical/IR astronomy. Dr Jenni Adams gave an invited talk on neutrino telescopes in Antarctica. Four members of the group attended and gave papers at IAU Colloquium 176 on The impact of large-scale surveys on pulsating star research in Budapest, Hungary, in August (Albrow, Hearnshaw, Pollard, L. Skuljan). Since this meeting marked the centenary of the Konkoly Observatory as a state institution in Hungary, Hearnshaw gave an introductory historical address to mark this occasion, as well as a paper on photometry of variable stars in the Magellanic Clouds, observed in the MOA project. Pollard gave an invited review on RV Tauri stars and type II cepheids in the Magellanic Clouds, as well as a poster paper on a spectroscopic survey of RV Tauri stars in the Clouds (with T. Lloyd Evans, SAAO). Pritchard attended a meeting for the opening of the Very Large Telescope in Antofagasta, Chile in March, and gave an oral paper on Magellanic Cloud eclipsing binaries. Pollard was a speaker at a conference on women in science at the Univ. of Otago in June. Bond attended the Ninth international conference on astronomical data analysis and software in Hawaii in November. He presented there a paper on time critical analysis by image subtraction. N. Rattenbury (the Mt John MOA winter observer for 1999) gave a paper on searching for optical afterglows of GRBs at the Fifth Huntsville GRB symposium. Barnes and Bayne were participants in

3 the Harley Wood Summer School (Sydney, July) and L. Skuljan in the conference for PhD students in astronomy in Kecskemet, Hungary in August and gave a paper on RCB decline phases. Hearnshaw went to a workshop on the history of astronomy at Tihany, Lake Balaton, Hungary in August and gave a paper on the history of photographic photometry. A PLANET microlensing workshop was organized by Pollard and Albrow in the Dept. of Physics and Astronomy in November. While in Hungary, four Canterbury astronomers all witnessed a magniﬁcent total eclipse of the Sun on August 11 under clear skies. William Tobin in France was also in the eclipse path, and reported that what he saw ‘remained grandiose even when viewed from under clouds’.

5 Instrumentation

The Hercules spectrograph construction has continued during 1999 under John Hearnshaw as project leader, with the collaboration of Graeme Kershaw (mechani- cal) and Garry Nankivell (Lower Hutt) for optical fabrication. Barnes has worked on the project for his PhD thesis. The ´echelle grating for the spectrograph was pur- chased from Spectronics Inc. (Rochester, N.Y.) and the BK7 cross-dispersing prism was received and sent to D. Cochrane (IRL, Lower Hutt) for optical ﬁguring and polishing. Good progress has been made, and it is anticipated that the spectrograph will be assembled and tested in 2000. Barlow and Frost have installed an SBIG guide camera on the CCD photometer head, which will enable autoguiding. Pritchard, with the assistance of Andrew Richards, has written a Linux-based data acquisition program called MoJo for the Mt John SITe CCD camera and installed this at Mt John in early August. It has been in routine use for all CCD camera operations on the 1-m telescope since that time.

6 Other research

This section gives further details, not included above, and highlights of selected research programmes. There have been a number of research highlights: two optical afterglows from gamma-ray bursts have been observed by Canterbury astronomers. One was discovered in May by Pollard, observing from SAAO, South Africa, and another was monitored by the MOA group in July, from Mt John. Albrow and Pollard (members of the PLANET group) analysed the microlensing light curve of MACHO 97-BLG- 41 and deduced that it could be accounted for by the rotation of a binary lens (see below). Gilmore discovered a rare naked-eye nova in May (Nova Velorum). Pooley, Hearnshaw and Pollard obtained spectra of Nova Velorum in May and June and also of another fainter nova in Sagittarius, in April, May and June.

4 Other members of the group have continued their research on various types of variable stars, including cepheids, RV Tauri stars, eclipsing binaries, active chromosphere stars, AGB stars, RCB stars and on radial velocities and galactic dynamics. Tobin (while in France) has continued working on a biography of LéonFoucault, and Hearnshaw worked on various aspects of the history of astrophysics at the Vatican Observatory, Specola Vaticana in Castelgandolfo in July to August. Petterson, with Albrow and Cottrell, reports that observations for his project on binary cepheids have been completed with over 2 years of spectroscopic observations using the SITe 1024×1024-pixel CCD being obtained and also observations using the Thomson 384×576-pixel PM3000 CCD before that. Analysis is nearing completion. A substantial database of radial-velocity information has been accumulated giving information on the pulsational velocities in the atmospheres of the cepheids observed and information on orbital motion for many of the stars. Pulsational modelling of selected stars has been conducted with some success. McSaveney reports that progress is being made in the investigation of hydro- dynamical and line formation processes in RV Tauri, W Virginis and BL Herculis stars. A spectroscopic and photometric observing program is underway at Mount John. Previously unanalysed spectra of the RV Tauri star U Mon are being analysed. Two startling developments have emerged. The long-term minimum, which occurs every 8 years, has proved much shallower than usual without the heightened Hα emission which normally occurs during it. Also, the usually regular star has shown two “flips” in its pattern of deep followed by shallow minima. It is unclear why this has happened. Pollard, as an affiliate of the MACHO collaboration, has been analysing MACHO photometry of RV Tauri stars and type II cepheids in the Magellanic Clouds. The data have allowed an investigation to be made of the physical properties of these evolved stars and the stability of their pulsational behaviour. She has also been obtaining spectra of the newly-discovered RV Tau stars and type II cepheids in the Clouds with T. Lloyd Evans (SAAO). Albrow and Pollard have continued as members of the PLANET collaboration, and international group that is seeking to find evidence of planetary bodies from the analysis of microlensing light curves. Research highlights in 1999 include the first measurement of stellar limb darkening by microlensing and the first statistical limits on the frequency of planetary companions to Galactic Bulge stars. Their most recent result indicates that the natural rotation of a typical binary lens can account for the unusual light curve of microlensing event MACHO 97-BLG-41 and that a motionless binary is not consistent with the data. This is the first time that rotation has been measured in a binary lens. Additional effects due to a recently-postulated planet orbiting the binary are not required, and PLANET data rule out the specific binary-plus-planet model that has been proposed. Albrow has made a study of the photometric stability of clump giants in the Galactic Bulge field surrounding microlensing event MACHO 98-BLG-006. The I− and V −band data were acquired as part of the PLANET project using the Yale 1-m

5 telescope at CTIO. After seeing corrections were applied to the DoPhot-reduced photometric data, he found that the majority of these stars are photometrically stable, but a small subset may be variable at the few per cent level. Albrow has also developed software for use in the reduction of échelle spectra with the STARLINK echomop package. These included routines for 2-dimensional wavelength calibration and automated continuum fitting. He also developed a technique for determining spectral-line rest-wavelengths in the “MJUO system” which allows the measurement of stellar radial velocities with a precision of ∼ 100 m/s from the échelle spectrograph mounted on the 1-m McLellan telescope. In addition, Albrow has been working on an analysis of the type II cepheid, κ Pavonis. The high-resolution spectroscopic data show the presence of the van Hoof effect, where spectral lines originating in different layers of the atmosphere are observed to have different radial velocity curves. Pritchard had 13 nights on the Danish 1.54-m telescope at ESO in Febru- ary, and he made uvby observations there of Magellanic Cloud eclipsing binaries. Pritchard also, in collaboration with Watson and Hearnshaw, has undertaken a Wilson-Devinney analysis of the light curve of the close eclipsing active-chromosphere binary, HD9770, comprising two K stars in a half-day orbit. Barnes and Tobin worked on the H and K profiles of β Pictoris. Bayne and Tobin have worked on the subject of eclipsing binary stars in the Magellanic Clouds. Bayne has implemented the Grison period-finding algorithm with a view to searching for eclipsing binaries in the MOA database. Hearnshaw visited the Universidad de Los Andes in Mérida,Venezuela, for two weeks in January and initiated research collaborations on Nova Centauri 1995 and on F-type supergiant stars with Dr P. Rosenzweig. Griffin (Auckland Observatory) observed on the 1-m McLellan telescope in Novem- ber, and as a result he reported 172 astrometric positions of near-Earth orbit asteroids (NEOs) and comets to the Minor Planet Centre, including those for 13 NEOs and ten comets. The comets included 108P Ciffreo, which was recovered at R = 19.5, and of Comet 1993J, which had high time resolution resolved morphological observations. During this run two new asteroids were discovered (1999 VM14 and 1999 VW22).

7 Miscellaneous

The 1999 year was the third of a triennium in which the Canterbury astronomy group has beneﬁtted from a grant from the Marsden Fund administered by the Royal Society of New Zealand for curiosity-driven research. The grant covers ﬁve research projects, namely stellar variability, cepheid variables, eclipsing binaries, β Pictoris and moving groups of stars. More details are given in the WWW site http://www.phys.canterbury.ac.nz/research/astronomy/marsdenplc.html, including the year two annual report.

6 The Canterbury astronomy group under Cottrell has made a bid for New Zealand to join the Southern African Large telescope (SALT) project as a 5% partner. In this respect the possibility of New Zealand contributing a high resolution ﬁbre-fed ´echelle spectrograph for SALT was one of the issues investigated by Bessell and Gillingham as part of the SALT feasibility study in November. They visited all the New Zealand centres with expertise in astronomy or in optical fabrication or instrumentation and reported favourably in December. Cottrell attended the 4th Interim SALT Board meeting in Cape Town in April and with Dr Glen Mackie (Victoria Univ. Wellington) and Assoc. Prof. Phil Yock (Auckland Univ.) he made preparations to host the 6th SALT Board meeting in Wellington and Christchurch in Feb. 2000. Cottrell, Hearnshaw and Tobin obtained a grant from the Univ. of Canterbury Research Committee for the SALT project and for the Hercules spectrograph.

8 The MOA project

The MOA (Microlensing Observations in Astrophysics) project has continued at Mt John during 1999. The project involves about six scientists in four institutions (including University of Canterbury Dept. of Physics and Astronomy) in New Zealand, and about two dozen scientists in six institutions in Japan. Principal investigators in N.Z. are Assoc. Profs. P.C.M. Yock (Auckland), D.J. Sullivan (Victoria), Dr R.J. Dodd (Carter Observ.) and J.B. Hearnshaw (Canterbury). The New Zealand operations are funded by a grant from the Marsden Fund to Auckland University. In 1999 a total of four MSc and ﬁve PhD students were working on the MOA project, three of these nine being at the University of Auckland, one at Victoria University of Wellington and the remainder at Nagoya University. Pamela Kilmartin worked half-time as an observer at Mt John for the project and Nicholas Rattenbury (Auckland Univ.) was MOA winter observer for the 1999 winter season at Mt John. Japanese MOA observers who spent time at Mt John included Drs M. Honma (Tokyo) and Y. Kanya (Kyoto), and graduate students T. Yanagisawa, T. Sumi, S. Noda and Y. Kato (all from Nagoya Univ.). During 1999 observations have been made with the 24 mega-pixel CCD camera MOAcam2 on the 61-cm B&C telescope at Mt John. The camera comprises a mosaic of 3 thinned back-illuminated SITe CCD chips. Each chip is 4096 by 2048 pixels. A Sun Enterprise 450 server was used for reducing the CCD images, which are archived onto DLT tape. By the end of 1999, Bond had practically completed work on the development of software for the reduction of MOA CCD images using the technique of diﬀerence imaging. It is planned to issue microlensing alerts using this software from the winter of 2000. Observations continued throughout the year of microlensing events towards the Magellanic Clouds and the Galactic Bulge. The MOA group, in collaboration with

7 the MPS group in the U.S., announced the probable detection of a low-mass planet orbiting the lens of microlensing event MACHO 98-BLG-35 in January. The analysis was based in part on Mt John MOA data obtained in 1998 July, when this event was monitored comprehensively from Mt John for three consecutive nights, almost without interruption. The remainder of the data used came from the MPS observations obtained at Mt Stromlo Observatory in Australia. This was the first evidence of any kind for a low-mass extrasolar planet in or near the habitable zone of another star. The high magnification microlensing event MACHO-99-LMC-2 was observed ex- tensively by the MOA collaboration. During five days around the peak of the event, a total of 400 measurements were obtained with a median sampling of minutes. The data are being analysed using difference imaging photometry. Preliminary results indicate that the event deviates from a single lens microlensing light curve. As with the previously studied high magnification event, MACHO-98-BLG-35, it is expected that the final analysis will yield strong constraints on the configuration of planetary systems in the lensing object. Observations by MOA observers have also been made to search for optical afterglows of GRBs after receiving alerts of GRBs from the Italian-Dutch BeppoSAX satellite. A number of such alerts have resulted in MOA images being acquired, and in one case in July, GRB 990712, the optical afterglow was successfully recorded. As in previous years, the continued operation of the project was made possible by the provision of telescope time by the University of Canterbury, and the provision of a CCD camera by Japan.

9 Weather at Mt John

The weather in 1999 had 27% of the night-time hours photometric. This was not quite as good as 1998, when 33% of the hours were photometric. However Mt John has experienced more photometric weather in the second half of the 1990s decade than in the ﬁrst half. The years 1998 and 1999 were the best of the decade. In 1999 there were 90 fully photometric nights (25%), 43 partly photometric nights (12%), 105 spectroscopic nights (28%) and 117 unusable nights (32%). These ﬁgures are compared with those of recent years in Table 1. The distribution of usable nights throughout the year is shown in Table 2.

10 Publications

Abe, F., Bond, I.A., Carter, B.S., Dodd, R.J., Fujimoto, M., Hearnshaw, J.B., Honda, M., Jugaku, J., Kabe, S., Kilmartin, P.M., Koribalski, B.S., Kobayashi, M., Masuda, K., Matsubara, Y., Miyamoto, M., Muraki, Y., Nakamura, T., Nankivell, G.R., Noda, S., Pennycook, G.S., Pipe, L.Z., Rattenbury, N.J., Reid, M., Rumsey, N.J., Saito, T., Sato, H., Sato, S., Sekiguchi, M., Sullivan,

8 Table 1: Table of Mt John weather, 1992–1999 Year Photometric Partly photom. Spectroscopic Unusable 1992 73 20% 47 13% 80 22% 166 45% 1993 63 17% 61 17% 75 21% 166 45% 1994 66 18% 59 16% 95 26% 145 40% 1995 73 20% 61 17% 105 28% 126 35% 1996 72 20% 77 21% 104 28% 113 31% 1997 79 22% 84 23% 86 24% 116 32% 1998 97 27% 74 21% 71 19% 123 34% 1999 90 25% 43 12% 105 28% 117 32%

Table 2: Table of usable nights distribution, 1999 Month Phot. nights Part phot. nights Phot. hours Per cent phot. Jan 12 15 81 43 Feb 14 16 117 56 Mar 9 9 78 26 Apr 5 11 70 22 May 8 13 109 29 Jun 7 12 99 25 Jul 7 11 87 22 Aug 11 18 139 39 Sep 3 8 38 13 Oct 3 7 34 13 Nov 4 5 32 16 Dec 7 8 31 20 Total 90 133 915 27

9 D.J., Sumi, T., Watase, Y., Yanagisawa, T., Yock, P.C.M. and Yoshizawa, M., Observation of the halo of the edge-on galaxy IC 5249, Astron. J. 118, 1999: 261–272.

Albrow M.D., Beaulieu J.-P., Caldwell J.A.R., DePoy D.L., Dominik M., Gaudi B.S., Gould A., Greenhill J., Hill K., Kane S., Martin R., Menzies J., Naber R.M., Pogge R.W., Pollard K., Sackett P.D., Sahu K.C., Vermaak P., Watson R., Williams A., Sahu M.S., (The PLANET Collaboration), A complete set of solutions for caustic-crossing binary microlensing events, As- trophys. J. 522, 1999: 1022–1036.

Albrow M.D., Beaulieu J.-P., Birch P., Caldwell J.A.R., Dominik M., Greenhill J., Hill K., Kane S., Martin R., Menzies J., Naber R.M., Pel J.-W., Pollard K., Sackett P.D., Sahu K.C., Vermaak P., Watson R., Williams A., Sahu M.S., (The PLANET Collaboration), Limb-darkening of a K giant in the Galactic bulge: PLANET photometry of MACHO 97-BLG-28, Astrophys. J. 522, 1999: 1011–1021.

Albrow M.D., Beaulieu J.-P., Caldwell J.A.R., DePoy D.L, Dominik M., Gaudi B.S., Gould A., Greenhill J., Hill K., Kane S., Martin R., Menzies J., Naber R.M., Pollard K., Sackett P.D., Sahu K.C., Vermaak P., Watson R., Williams A., Pogge R.W. (The PLANET Collaboration), The Relative Lens-Source Proper Motion in MACHO 98-SMC-1, Astrophys. J. 512, 1999: 672–677.

Aminzade R., Sullivan, D.J., Xiaojun Jiang, Moshkalyov V.G., Seetha S., Ashoka B.N., MeiˇstasE., Solheim J.-E., GonzálezPérezJ.M., Garrido R., Sánchez del R´ıoJ., Fernandez A., Pau S. and Herpe G. The recent EC 15330– 1403 campaign, 11th European Workshop on White Dwarfs (Solheim, J.-E. & Meiˇstas,E. eds), ASP Conf. Ser., 169: 1999, 305–308.

Cottrell, P.L. and Mackie, G. (editors), The Foresight Project – Astronomy and Astrophysics in the ﬁrst decade of the new millennium, submitted to MoRST, 31 October 1998: 1–27.

Cottrell, P.L. and Mackie, G., New Zealand Astronomy and Astrophysics in the ﬁrst decade of the new millennium: a summary, Southern Stars, 38: 1998, 51–61.

Cummings, I.N. and Hearnshaw, J.B., High precision radial-velocity measurements of late-type evolved stars, Astron. Soc. of the Paciﬁc Conf. Series, 185, 1999: 204–210.

Gaudi B.S., Albrow M.D., Beaulieu J.-P., Caldwell J.A.R., DePoy D.L., Do- minik M., Gould A., Greenhill J., Hill K., Kane S., Martin R., Menzies J., Naber R.M., Pogge R.W., Pollard K.R., Sackett P.D., Sahu K.C., Vermaak P.,

10 Watson R., Williams A., Microlensing constraints on the frequency of Jupiter- mass planets, Bull. Amer. Astron. Soc., 195: 1999, 2404.

Hearnshaw, J.B. & Scarfe, C.D., eds., Precise stellar radial velocities (Intl. Astron. Union Coll. 170), Astron. Soc. Paciﬁc Conf. Series 185, publ. by Astron. Soc. Paciﬁc, San Francisco, CA, 1999: pp. xxiv+431.

Hearnshaw, J.B., Access to telescopes in developing countries, (Presented at IAU General Assembly, Joint Discussion 20 on astronomy in developing countries, Kyoto, Japan, Aug. 1997, ed. A.H. Batten.) IAU Highlights in Astron- omy, 11B, 1998: 920–922.

Hearnshaw, J.B., An analysis of Almagest magnitudes to study stellar evolu- tion, (Presented at IAU General Assembly, Joint Discussion 8 on stellar evolu- tion in real time, Kyoto, Japan, Aug. 1997, eds. E.F. Guinan and R.H. Koch.) New Astronomy Reviews, 43, 1999: 403–410. Abstract in IAU Highlights in Astronomy, 11A, 1998: 345.

Hearnshaw, J.B., Rumsey, N.J. & Nankivell, G.R., Some comments on the design of ´echelle spectrographs using R2 or R4 gratings (Paper presented at IAU Coll. 170, Precise stellar radial velocities, Victoria, B.C., Canada, June 1998) Astron. Soc. of the Paciﬁc Conf. Series, 185, 1999: 29–35.

Kilkenny D., Koen C., O’Donoghue D., van Wyk F., Larson K.A., Shob- brook R., Sullivan, D.J., Burleigh M.R., Dobbie P.D. and Kawaler S.D., The EC 14026 stars – X. A multi–site campaign on the sdBV star PG 1605+072, Mon. Not. Roy. Astron. Soc., 303, 1999: 525–534.

Mackie, G., Cottrell, P.L. and Yock, P. “Pass the SALT, please”, New Zealand Science Monthly, November 1998: 8–9.

Mackie, G., Cottrell, P.L. and Yock, P. The Need for Vision, New Zealand Education Rev., 19 November 1999: 7.

Muraki, Y., Sumi, T., Abe, F., Bond, I., Carter, B., Dodd, R., Fujimoto, M., Hearnshaw, J.B., Honda, M., Jugaku, J., Kabe, S., Kato, Y., Kobayashi, M., Koribalski, B., Kilmartin, P., Masuda, K., Matsubara, Y., Nakamura, T., Noda, S., Pennycook, G., Rattenbury, N., Reid, M., Saito, To., Sato, H., Sato, S., Sekiguchi, M., Sullivan, D., Takeuti, M., Watase,, Y., Yanagisawa, T., Yock, P. and Yoshizawa, M., Search for MACHOS by the MOA collaboration, Progress of Theor. Phys. Suppl. 133, 1999: 233–246.

Nitta A., Winget D.E., Kanaan A., Kepler S.O., Sullivan, D.J., Kleinman S.J., Grauer A.D., Shobbrook R., Buckley D.A.H., O’Donoghue D., Krzesi´nskiJ., Van Zyl L., O’Brien M.S., Montgomery M.H., Nather R.E., Provencal J.L. and Watson T.K., A way to the interior of a crystallized white dwarf: BPM 37093,

11 11th European Workshop on White Dwarfs (Solheim, J.-E. & Meiˇstas,E. eds), ASP Conf. Ser. 169, 1999: 144–148.

Petterson, O.K.P. and Tobin, W., β Pictoris: the variable CaII H and K absorptions from 1994 to 1996 Mon. Not. Roy. Astron. Soc., 304, 1999: 733–742.

Pooley D.J, Albrow M.D., Pollard K.R., Cottrell, P.L., Spectroscopic moni- toring of southern post-AGB stars, Southern Stars, 38, 1999: 105.

Pollard K.R., Astronomy and Astrophysics in NZ – A personal perspective, Proceedings of the Living Science Conference, Dunedin, Univ. of Otago, 1999: 192–196.

Skuljan Lj. and Cottrell, P., Spectroscopic and photometric observations of the R Coronae Borealis stars S Apodis and RZ Normae throughout their recent declines, Mon. Not. Roy. Astron. Soc., 302, 1999: 341–346.

Skuljan, J., Hearnshaw, J.B. & Cottrell, P.L., Velocity distribution of stars in the solar neighbourhood Mon. Not. R. astron. Soc. 308, 1999: 731–740.

Skuljan, J., Hearnshaw, J.B. & Cottrell, P.L., Using the radial-velocity spec- trometer at the Dominion Astrophysical Observatory Paper presented at IAU Coll. 170, Precise stellar radial velocities, Victoria, B.C., Canada, June 1998 Astron. Soc. of the Paciﬁc Conf. Series, 185, 1999: 98–101.

Skuljan, J., Hearnshaw, J.B. & Cottrell, P.L., Absolute radial velocities by cross-correlation with synthetic spectra Paper presented at IAU Coll. 170, Precise stellar radial velocities, Victoria, B.C., Canada, June 1998 Astron. Soc. of the Paciﬁc Conf. Series, 185, 1999: 91–97.

Sullivan, D.J., Period changes in the pulsating white dwarfs, 11th European Workshop on White Dwarfs (Solheim, J.-E. & Meiˇstas,E. eds), ASP Confer- ence Series 169, 1999: 85–91.