This white paper emphasizes critical importance of preservation, digitization and scientific exploration of historical astronomical data. It outlines the rationale, provides examples of new science with such data, and reviews the potential losses to science if nothing it done.

We present a status report of the original EROS and the on-going EROS-2 microlensing surveys, which were created to search for dark matter in the Galactic halo via microlensing effects on LMC/SMC stars. Microlensing surveys provide long-term systematic observations of millions of stars in both Clouds which yield a unique database of stellar photometry and variability. We review the results obtained on pulsating stars and detail the similarities and differences of the Magellanic Cloud Herbig Ae/Be stars with their Galactic counterparts. 1. Observations Made By the EROS Microlensing Survey EROS (Experience de Recherche d'Objets Sombres) is a French collaboration between astronomers and particle physicists to search for baryonic dark matter in the Galactic halo by the microlensing (Paczynski 1986) of stars in the Magellanic Clouds (MCs). A compact object in the Galactic halo passing close enough to the line of sight to a background star in the Magellanic Clouds creates an increase in the apparent brightness of the star. This phenomenon occurs during a chance alignment of the observer, the deflector, and the background star. If one assumes a standard co-rotating halo, the time scale TO of a microlensing event is given by the relation TO == 70JM/M0 days where M is the mass of the deflector. To be sensitive to a wide range of mass for compact objects (107 10M0 ) two complementary approaches have been developed. The first approach involved photographic monitoring of 6.4 million stars over a 5 X 5 degree field using the ESO Schmidt telescope from 1990 to 1994. When possible, the plates were taken once a night in BJ and Re. Isolated stars can be found down to magnitude 20 with typical photometric uncertainties of 0.3 mag. The second approach was sensitive to low mass compact objects. Between 1991 and 1994 about 15000 CCD images were taken with two broad bandpass filters BE and RE of an area of 1 x 0.4 degrees centered on the bar of the LMC. An SMC field of 1 x 0.4 degrees was observed between 1993-1995 and about 6000 images were taken. Light curves of 270,000 stars exist with up to 48 points per night!

AbstractConstruction of Canada's Dominion Astrophysical Observatory (DAO) commenced in 1914 with first light on 6 May 1918. As distinct from the contemporaneous development with private funding of major observatories in the western United States, DAO was (and remains) funded by the federal government. Canada's initial foray into ‘big science’, creation of DAO during the First World War was driven by Canada's desire to contribute significantly to the international rise of observational astrophysics enabled by photographic spectroscopy. In 2009 the Observatory was designated a National Historic Site. DAO's varied, rich contributions to the astronomical heritage of the 20th century continue in the 21st century, with particularly strong ties to Maunakea.

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ring Rabs = (6.23 ± 0.08) X 10 ern and an angular size R" = 808 ± 17 mas, which give a distance to the supernova d(SN1987A) = 51.4 ± 1.2 kpc and a distance modulus m M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to be d(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus of m-M(LMC) = 18.58±0.05.

Recent optical and infrared studies of 30 Doradus have revealed a more complex and diverse star-formation history than previously recognized. Five spatially and/or temporally distinct populations have been identified, including a new generation currently being triggered by the R136 cluster in its surroundings. HST /NICMOS observations of the latter provide insights into the phenomena of triggered massive-star formation, as well as the global structure and evolution of the starburst region. 1. Stellar Populations A groundbased, blue-violet spectral classification study of the 30 Doradus stellar content by Walborn & Blades (1997) has revealed five spatially and/or temporally distinct components: 1. The central ionizing cluster including R136 corresponds to the Carina phase of OB cluster evolution, with an age of 2-3 Myr. HST/FOS spectroscopy by Massey & Hunter (1998) has shown that two-thirds of the 60 brightest stars in and around R136 are of spectral type 03, by far the richest concentration known of these hottest and most massive young stars. 2. A younger, Orion-phase generation of age < 1 Myr, in or near the bright nebular filaments west and northeast of R136, containing heavily embedded early-O dwarfs and IR sources, has likely been triggered by the central cluster. This component is further discussed in the second section below. 3. An older population of late-O and early-B supergiants throughout the central field represents the Scorpius OBI phase with age 4-6 Myr and has no clear structural relationship to the younger groups. These stars may simply belong to the larger young region in which 30 Doradus is embedded. 4. The previously known, older still compact cluster Hodge 301, 3' northwest of R136, contains A and M supergiants and corresponds to the h and X Persei phase, of age 10 Myr. 5. A newly recognized Sco OBI-phase association surrounds the recently discovered Luminous Blue Variable R143 in the southern part of the Nebula. Evidently, star formation has occurred in discrete events at different epochs In 30 Doradus. Global CMDs and IMFs of the region will be heterogeneous 213 available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0074180900117863 Downloaded from https://www.cambridge.org/core. IP address: 54.70.40.11, on 22 Jan 2019 at 05:16:58, subject to the Cambridge Core terms of use, 214 Walborn and Barba composites (see also Barba & Walborn in these proceedings), and there are clear implications for the interpretation of more distant starbursts. This entire region would subtend ~/5 at the Virgo Cluster. 2. HST/NICMOS Views of the New Generation Recent optical, IR, and radio evidence for current star formation in 30 Doradus is reviewed by Rubio et al. (1998) and Walborn et al. (1999). The latter paper presents first results from an HST/NICMOS survey, which because of its 0'!1 resolution provides new insights; some further observational details are given by Barba et al. in these proceedings. Many new IR sources, including multiple systems, clusters, and nebular structures, are found in these NICMOS images. Knots 1-3 of Walborn & Blades (1997), early 0 stars embedded in dense nebular knots, are all found to be compact multiple systems. The first of the accompanying figures shows the field of Knots 1 and 2 (northeast of R136) in a WFPC2 U, V, I composite, and the second in a NICMOS J, H, K composite with the same orientation and scale; the scale bars indicate N, E and are 4" = 1 pc in length. Knot 1 resides at the top of a massive dust pillar oriented directly toward R136, whose summit has just been removed, exposing the newborn stellar system. Two of the brightest IR sources in 30 Dor (arrowed in the 'NICMOS figure), with only very faint counterparts in I, are found in an adjacent pillar with the same orientation just northeast of Knot 1. Another very bright IR source is within the head of a pillar near Knot 3 also oriented toward R136 (west of R136, not shown here), while parsec-scale jet structures have been discovered in association with Knots 2 and 3. The Knot 2 structures, arrowed in the accompanying NICMOS figure, consist of detached, nonstellar IR sources aligned on either side of the stellar system, which are interpreted as impact points of a highly collimated, possibly rotating bipolar jet on the surrounding dark clouds; there is also an H20 maser in this field. The outflows from young massive stars in 30 Dor are the first extragalactic examples of the phenomenon. These results establish the 30 Doradus Nebula as a prime region in which to investigate the formation and very early evolution of massive stars and multiple systems; several sequential stages and their interstellar interactions are directly observable in the optical and IR. The theme of triggered formation within the heads of extensive dust pillars oriented toward R136 is strong. In addition, these results provide further insights into the global structure and evolution of 30 Doradus, which are significant in view of its status as the best resolved extragalactic starburst. As discussed by Scowen et al. (1998), the most intense nebular emission arises from filamentary interfaces between the central cavity and surrounding molecular clouds. The IR results show that these interfaces are in fact star-formation fronts moving into the dark clouds. 30 Doradus is a two-stage starburst, in which a second generation of massive stars is being triggered around the periphery of the initial, massive central cluster. It will evolve into a giant shell H II region like NIl in the LMC (Walborn & Parker 1992) and NGC 604 in M33. Acknowledgments. Support for this work was provided by NASA through grants numbers GO-7819.01-96A and AR-7545.01-96A from STScl, which is operated by AURA, Inc., under NASA contract NAS 5-26555. available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0074180900117863 Downloaded from https://www.cambridge.org/core. IP address: 54.70.40.11, on 22 Jan 2019 at 05:16:58, subject to the Cambridge Core terms of use,

This review concentrates on the oldest populations in the LMC. Specifically, the LMC has a large extent and mass, it has star clusters coeval with those in the Milky Way halo, and more work needs to be done before we are convinced that there are similarly-aged field stars in the LMC. Further, all studied fields in the Clouds are different from Milky Way halo fields. Observations with the new generation of large telescopes can clear up the uncertainties noted in this review.

The molecular gas content in the Magellanic Clouds has been studied, with different spatial coverage and resolution, through obervations of CO(1-0) line emission. In the LMC and the SMC the molecular gas is dominated by clouds whose properties are different from those of their Galactic counterparts. The relation between the intensity of CO emission and molecular hydrogen column density, or the conversion factor X, is different than that of molecular clouds in our Galaxy and depends on the ambient physical conditions. Studying the molecular gas through observations in the H2 emission line may prove an alternative way to determine the molecular content associated with star forming regions in the Magellanic Clouds. In particular, results obtained towards 30 Doradus in the LMC are presented.

The stellar associations are defined as loose unbound concentrations of young stars with a bright OB stellar component, mainly located at the most recent star forming regions, representing the smallest units in the hierarchy of stellar systems in galaxies. The definition of the associations is discussed and the main properties of their stellar content are summarized. Using plates taken with the 1.2m UK Schmidt Telescope a method is developed to detect all stellar associations in the LMC and to find their spatial distribution relative to the LMC's recent star formation history. In 40% of the LMC region, the number of "single peak" associations has increased considerably (rv 3x). A very interesting result is that the faint limit, where the identified associations are revealed, varies by about 3 mag. This indicates not only extinction differences but also the presence of pre-main sequence stars at a wide range of masses.

Fellow of the RAS, stellar spectroscopist who pioneered the calculation of synthetic spectra and their diverse applications.

JRASC April / avril 2010 Promoting Astronomy In Canada of Texas Press. Coe, Michael D. (1975). Native Astronomy in Mesoamerica. In A.F. Aveni (Ed.) Archaeoastronomy in Pre-Columbian America. Austin, Texas, and London, England: University of Texas Press. Duran, Fray Diego (1579). Book of the Gods and Rites and the Ancient Calendar. Translated by F. Horcasitas & D. Heyden (1971). Norman, Oklahoma: University of Oklahoma Press. Frazer, James George (1922). The Golden Bough. New York, New York: MacMillan. McDowell, B. (1980). The Aztecs. National Geographic, Dec. 1980, 158 (6). McIvor, R.S. (2000). Star Patterns on the Aztec Calendar Stone. JRASC, 94 (2). Nuttall, Zelia (1901). The Fundamental Principles of Old and New World Civilizations. Figure 56. Cambridge, Massachusetts: Harvard University Press. Sahagun, Fray Bernardino de (1569). The Florentine Codex, General History of the Things of New Spain: Book 7: The Sun, Moon, and Stars, and the Binding of the Years. Translated by A.J. Anderson & C.E. Dibble (1953). Santa Fe, New Mexico: The School of American Research & The University of Utah.

www.astronomy2009.ca The Canadian IYA 2009 bilingual web site was created by Marc Jobin from the Planetarium de Montreal James E. Hesser1, C. Bartlett2, K. Breland3, K. Hay3, D. Lane3, R. Lacasse4, D. Lemay4, P. Langill5, J. Percy6, D. Welch7, A. Woodsworth8 1NRC-HIA and CASCA, Canada, 2 CBU, Canada, 3RASC, Canada, 4FAAQ, Canada, 5U. Calgary, Canada, Canada, 6U. Toronto and CASCA, Canada, 7McMaster U. and CASCA,Canada, 8Galaxy Consulting, Canada.