The next generation of ground based telescopes will break the 20th century paradigm of the 'factor of two' diameter increase. Taking advantage of the enormous advances in technology that the present generation of 8-10m telescopes has fostered, they will be fully adaptive, fully steerable behemoths of up to 100m diameter performing at the diffraction limit in the optical and near IR. At ten times the collecting area of every telescope ever built put together, they will have limiting magnitudes of 37-38, angular resolution of 1-2 milliarcseconds, and a price tag that does not follow the historical D^2.6 cost law. In this paper we discuss some of the possible science cases for a telescope of 100m. Among them the determination of H unencumbered by local effects, the study of every SN ever exploded at any z < 10, the spectroscopy of extra-solar planets, studies of ultrahigh frequency phenomena, imaging of stellar surfaces, detection of brown dwarfs in external galaxies. The advent of the next generation of Extremely Large Telescopes will probably substantially change the operation all paradigm of astronomical observations, expanding on the present trend towards large programs, much in the way particle physics has gone with the large accelerators.

Gamma-ray burst astronomy has undergone a revolution in the last three years, spurred by the discover of fading long- wavelength counterparts. We now know that at least the long duration GRBs lie at cosmological distances with estimated electromagnetic energy release of 10⁵¹-10⁵³ erg, making these the brightest explosions in the Universe. In this article we review the current observational state of the long-lived 'afterglow' emission that accompanies GRBs at X-ray, optical, and radio afterglow wavelengths. We then discuss the insights these observations have given to the progenitor population, the energetics of the GRB events, and the physics of the afterglow emission. We focus particular attention on the evidence linking GRBs to the explosion of massive stars. Throughout, we identify remaining puzzles and uncertainties, and emphasize promising observations tools for addressing them. The imminent launch of HETE-2, the increasingly sophisticated and coordinated ground-based and space-based observations, and the increasing availability of 10-m class optical telescopes have primed this field for fantastic growth.

There has been considerable progress made in the discovery, observation, and understanding of high redshift galaxies in the last few years; most of this progress is attributable to greatly improved spectroscopy throughput made possible by state-of-the-art instruments on the new generation of 8-10m telescopes. Here we review a few of the areas in which substantial progress has been made, and discuss the future of high redshift galaxy work in the context of the observational facilities that are either in operation or soon to come.

The first of the 10m class telescopes allow us to study the formation of structure in the universe in exquisite detail. New results obtained over the past six years include the measurement of cosmological parameters from the intergalactic medium, the assembly of galaxies from gas, the universal metal enrichment as a result of early star formation, and observations of the interstellar medium in young galaxies on scales of only a few tens of parsecs.

We present the main results of a project aimed at understanding the nature of extremely red galaxies (ERGs) and their role in galaxy formation and evolution. The paper is focused on recent near-IR spectroscopy of ERGs made with the ESO VLT-UT1 equipped with ISAAC. Neither strong emission lines nor continuum breaks were detected in their near-IR spectra. The optical to near-IR spectral energy distributions of the observed ERGs suggest that 0.8 < z < 1.8 and that most of them are passively evolving elliptical galaxies. The main results of complementary HST and sub mm observations are also presented. Finally, we discuss what the present result tell us about the nature of ERGs and on their relation with the problem of the formation and evolution of elliptical galaxies.

The IR Spectrometer and Array Camera (ISAAC) at the VLT has ben used for follow-up spectroscopy of 11 candidate H(alpha) emitting galaxies at z approximately equals 2.2 detected in a preparatory, IR narrow band filter imaging survey. This survey was conducted with Son of ISAAC at the ESO NTT and covered an area of 100 sq. arcmin including the WFPC2 and STIS fields in the HDFS. Line emission within the wavelength range of the 2.1 micrometers narrow band filters is confirmed in 6 of the candidates and in all but one of the 6 detected at >= 4 (sigma) in the survey. Although only a single emission line is observed its identification with H(alpha) is relatively secure and the absence of (NII) (6548,6584 Angstrom) is consistent with high ionization and/or low metallicity systems. Velocity dispersions and one H(alpha) rotation curve imply masses of up to approximately 10¹⁰M. Star formation rates of the individual galaxies derived from the H(alpha) fluxes are 20-35 M yr^-1 and the total star formation rate density is 0.12 M Mpc^-3. This is the same as found at z approximately equals 1.3 from H(alpha) observations with NICMOS on HST$_1) and close to that at z equals 3-4.5 derived from the extinction corrected UV continuum fluxes of Lyman Break galaxies².

The 8.2m Subaru Telescope had its astronomical first light at the Cassegrain focus in January 1999. Commissioning of the telescope and its open use instruments are in progress. The scientific observations carried out so far are limited to the imaging observations using an optical camera, Suprime-Cam equipped with six 4K X 2K CCDs, and a near IR camera, CISCO with a 1K X 1K HgCdTe detector array. It was shown that Subaru has superb imaging performance. Described in this overview is a brief summary of the result from the 8 papers reporting the studies on extragalactic objects; a cluster of galaxies Abell 851, gravitational lensed quasar PG1115+080, radio galaxy B3 0731+438, radio galaxy 3C324 and its associated cluster, and the Hubble Deep Field North.

Reviewed in this paper are the recent and potential advances made with 10m-class telescopes on the chemical abundances of proto-galaxies in the early universe. In particular, we focus on measurements of the damped Ly(alpha) systems, layers of neutral hydrogen gas which dominate the HI content of the universe. Observed along the sightline to distant quasars, these systems are the progenitors of present-day galaxies. Therefore, analyses on the abundances of these systems provide direct insight into the chemical evolution of the universe at high redshift. The advent of 10m-class telescopes and efficient high resolution spectrographs have enables great progress on damped Ly(alpha) chemical abundances, particularly in two areas: (1) studies of the relative abundance patterns in the ISM of individual protogalaxies; and (2) metallicity measurements at z > 3. In this proceedings, we discuss these result and describe their impact on our understanding of chemical evolution in the early universe. Finally, we detail the areas of chemical abundance research that we believe should be the focus of future studies with current and new instruments on large telescopes.

There is considerable evidence that powerful radio quasars and radio galaxies are orientation-dependent manifestations of the same parent population: massive spheroids containing correspondingly massive black holes. Following the recognition of this unification, research is directed to the task of elucidating the structure and composition of the active nuclei and their hosts to understand the formation and evolution of what we expect to become the most massive of galaxies. In contrast to the quasars, where the nucleus can outshine the galaxy at optical/near IR wavelengths by a large factor, the radio galaxies contain a 'built-in coronograph' that obscures our direct view to the nucleus. These objects present out best opportunity to study the host galaxy in detail. Of particular interest are those sources with redshifts greater than about 2 that represent an epoch when nuclear activity was much more common that it is now and when we believe these objects were in the process of assembly. In combination with high resolution imaging from space, optical spectropolarimetry with Keck II allows us to clearly separate the scattered nuclear radiation from the stellar and gaseous emission from the host galaxy. The rest- frame UV emission line spectra suggest that rapid chemical evolution is occurring at this epoch. Near IR spectroscopy with the VLT is giving us access to both the lines and continuum in the rest-frame optical spectrum, allowing investigations of the evolved stellar population and extending the composition analysis with measurements of the familiar forbidden-line spectrum.

At low redshifts powerful radio sources are uniquely associated with massive galaxies, and are thought to be powered by supermassive black holes. Modern 8m-10m telescopes may be used to find their likely progentors at very high redshifts to study their formation and evolution.

In order to constrain models of particle acceleration in Active Galaxies with spectral energy distributions that are dominated by non-thermal radiation mechanisms, we carried out polarimetric observations with the FORS1 instrument on UT1 of the ESO-VLT. These studies involve imaging and spectropolarimetry of both circular and linear modes of polarization.

We present high precision spectropolarimetry of five bright Seyfert 1 galaxies taken with FORS1 on the VLT. We investigate for our targets the new diagnostic potential opened up by high signal-to-noise spectropolarimetry with large telescopes.

We report NIRSPEC/Keck observations of the Galactic Center obtained in both low and high resolution modes under excellent seeing conditions. The data were obtained as part of the NIRSPEC commissioning program and will be used to determine: 1) the nature of the stars in the central 0.02 pc, 2) the velocities and accelerations of stars around the central black hole, 3) the velocities of ionized gas in the central parsec, 4) the extent of the main sequence population and star formation history in central parsec, 5) the mass magnitude relation and initial mass function in the Arches cluster, 6) the nature of the MIR sources in the central parsec and Quintuplet clusters, 7) the physical parameters of stellar atmosphere/winds of super luminous stars, and 8) the metallicity in the GC as inferred from observations of red supergiants, red giants, and hot stars. We present a sample of these data, including a high resolution slit scan movie of the central parsec, and show how they can be used to vastly improve the current state of the art in the related science topics. Further, we discuss preliminary results concerning the nature of the central cusp stars and the resultant implications for star formation near a supermassive black hole.

UVES is a dual beam echelle spectrograph installed at the Nasmyth focus of the UT2 telescope of the ESO VLT since October 1999. It can reach a resolution of 80000 and 115000 in the blue and red arm, respectively. The instrument is characterized by great stability and high efficiency. The smooth operation of both the new telescope and instrument has lead to a remarkable number of highly interesting scientific observations during commissioning. Examples of scientific work on these data are presented to illustrate the unique UV efficiency, the resolving power and high S/N capability and far red efficiency.

ISAAC is an IR imager and array camera operating from 0.9 to 5 micrometers . This paper illustrates some preliminary scientific results which have been obtained during its first year of science operations. In Low Resolution Spectroscopy, we present results obtained on one Centaur, on TMR1-C and the detection of a methane brown dwarf. In Medium Resolution Spectroscopy, we present results obtained on kinematics studies in the central kpc of AGNs, and of emission line detections of distant galaxies at various redshift, from 0.6 to 3.

Imaging surveys of the bright 5007 angstrom line in nearby early-type galaxies and the bulges of spirals have catalogued many planetary nebulae. Planetary nebulae arise from the late stages of evolution of low mass stars and are thus representative of a large fraction of the stellar population by number. In about 80 percent of planetary nebulae the abundances of the well observed lighter elements are not affected by the nucleo synthesis which occurs on the Asymptotic Giant Branch, so the nebular abundances can be related to those of the progenitor star. Planetary nebular abundances compared with those of H II regions in spirals, as indicators of abundance gradients and enrichment history. Planetary nebulae provide point probes of the stellar abundance and, in contrast to integrated line of sight stellar spectra, can be used to measure the abundance spread.

Spectroscopic observations at high spectral resolution of unevolved stars in globular clusters have only been possible since the 1993 advent of the Keck-I 10-meter telescope and its high-resolution spectrometer. Our program of deriving chemical abundances of lithium and several other elements in some unevolved, but identical, stars in three globular clusters is described. For M13 we have found a spread in Li abundances of a factor of five in four very similar stars. For six stars in M92 the range is a factor of three and for five in M71 the range is a factor of two. The stars with the highest abundances of Li show values that are a factor of two above the field halo star Li plateau. The abundances of several other species - Na, Mg, Si, Ca, Ti, Cr, Ni, Fe, Y, and Ba - show no such star-to-star variations. These abundances are compared with those of halo field stars which were derived from Keck HIRES spectra.

We report on the detailed abundances of giants in the Galactic bulge, measured with the HIRES echelle spectrograph on the 10-m Keck telescope. We also review other work on the bulge field population and globular clusters using Keck/HIRES. Our new spectra have 3 times the resolution and higher S/N than previous spectra obtained with 4m telescopes. We are able to derive log g from Fe II lines and excitation temperature from Fe I lines, and do not rely on photometric estimates for these parameters. We confirm that the iron abundance range extends from -1.6 to +0.55 dex. The improved resolution and S/N of the Keck spectra give (Fe/H) typically 0.1 to 0.2 dex higher than previous studies, for bulge stars more metal rich than the Sun. Alpha elements are enhanced even for stars at the Solar metallicity. We confirm our earlier abundance analysis of bulge giants and find that Mg and Ti are enhanced relative to Ca and Si even up to (Fe/H) equals +0.55. We also report the first reliable estimates the bulge oxygen abundance. Our element ratios confirm that bulge giants have a clearly identifiable chemical signature, and suggest a rapid formation timescale for the bulge.

We present Keck 10-meter/LRIS spectra of candidate red giants in the halo of M31, located at a projected radius of R equals 19kpc on the minor axis. These spectroscopic targets have been selected using a combination of UBRI-based and morphological screening to eliminate background galaxies. Radial velocity measurements are used to separate M312 halo giants from foreground Milky Way dwarf stars, M31 disk stars, and residual background galaxies. The metallicity of each M31 halo giant is measured using standard photometric and spectroscopic techniques, the latter based on the strength of the Ca II triplet. The various (Fe/H) estimates are in rough agreement with one another. The data reveal a large spread in (Fe/H) in M31's halo; there is no strong radial (Fe/H) gradient. LRIS and HIRES spectra are also presented for red giants in five dwarf spheroidal satellites of M31: AndI, AndIII, AndV, AndVI, and AndVII. There appears to be a significant metallicity spread in AndVI and possibly in AndI. The new radial velocity data on these outer dwarfs are used to constrain the total mass of M31: the best estimate in under 10¹² M, somewhat less than the best estimate for the Milky Way.

We used FORS2 at UT2 of the VLT to obtain low resolution spectra of early type emission line stars in the field of the young open SMC cluster NGC 330. This cluster is known for its exceptional large number fraction of Be stars and could play a key role in constraining the Be phenomenon in general. 48 of the 59 program stars identified as H(alpha) excess sources by CCD imaging photometry can be confirmed to show H(alpha) line emission superimposed on a strong continuum. Comparison with VLT-FORS1 spectra collected a year earlier shows no or only a low significance of variability on the time scale of a year. To test the prediction of the hybrid model for global disk oscillations in Be star circumstellar disks we compared the number ratio of Be stars with asymmetric line profiles to the total number of Be stars with the known ratio of galactic field Be stars. About 10 of 47 emission line stars show asymmetric line profiles hence the theoretical prediction is not matched. We discuss several possibilities which might explain the discrepancy.

We present diffraction limited 2-25 micrometers images, obtained with the W.M. Keck 10-m telescopes that spatially resolve the cool Galactic Center source IRS 21, an enigmatic object that has alluded classification. Modeled as a Gaussian, the azimuthally averaged intensity profile of IRS 21, an enigmatic object that has alluded classification. Modeled asa a Gaussian, the azimuthally averaged intensity profile of IRS 21 has a HWHM radius of 740 +/- 30 AU at 2.2 micrometers and an average HWHM radius of 1540 +/- 90 AU at mid-IR wavelength. These sizes along with its color temperature favor the hypothesis that IRS 21 is self-luminous rather than an externally heated dust clump. Based on the size alone, the remaining possible dust geometries are (1) an intrinsic inflow or outflow or (2) an extrinsic dust distribution, in which case IRS 21 could be simply embedded in the Northern Arm. A simple SED model of the IR photometry from the literature and our mid-IR images reveal that the near-IR radiation is scattered light from an unknown embedded source while the mid-IR radiation is the remaining re-radiated light. The agreement between the 2.2 micrometers polarization angle for IRS 21 and the 12.5 micrometers polarization angle at the position of IRS 21, the symmetric shape of its intensity profiles, as well as the similarity of the observed properties of all the Northern Arm sources, lead us to conclude that the scattering dust around IRS 21 is extrinsic to the central source and is associated with the Northern Arm.

The current generation of large optical/IR telescopes will make a great impact on the study of the origin an devolution of stellar and planetary systems. The considerable collecting area, excellent spatial resolution, and reduced thermal background of the new 8-10 meter class telescopes all combine to yield sensitivities which will enable us to detect and characterize young low-mass stars, brown dwarfs, and giant planets at kiloparsec distances, thus including many dense clusters embedded in giant molecular clouds, where most stars in the galaxy are born. In the nearby star- forming regions, the faint surface brightness sensitivity and high spatial resolution will allow us to probe the environment of young stars in scattered and intrinsic emission on scales from 0.1 parsec, the original size of the protostellar core, to 10AU, where young giant planets may be forming in a circumstellar disk. We review recent star formation results from large ground-based optical/IR telescopes, predominantly the VLT and Keck, which serve to illustrate outstanding questions and to preview important insights that should be yielded by the armada of 8-10 meter ground-based telescopes over the coming decade. We also look forward to the further leap in capability that will be delivered at the end of the decade by the NGST, a cryogenic space-based 8 meter telescope which will have extremely low backgrounds at optical to mid-IR wavelengths and be diffraction-limited over a wide field in the near-IR and longwards.

This invited paper reviews the first scientific results to emerge from NIRSPEC, a new near-IR cryogenic spectrograph for the Keck II 10-meter telescope. In its lowest resolution mode, NIRSPEC is sufficiently sensitive for deep extra- galactic work, as illustrated by observations of a gravitational lense galaxy at a redshift of z equals 2.7. This resolution also provides a powerful tool for a spectroscopic survey of brown dwarfs. The power of NIRSPEC's high- resolution echelle mode is illustrated with studies of star- forming regions, interacting galaxies and the Galactic Center. As well as solar system bodies such as comets and the outer planets. Prospects for use of NIRSPEC with the Keck adaptive optics system are also discussed. NIRSPEC demonstrates that, withe availability of large-format, low- noise array detectors, IR astronomy is now capable of many challenging applications in spectroscopy.

This article describes results of the first light observations of the Orion nebular an dL1551 IRS 5 carried out with the Subaru telescope in January 1999. The new RI images of the Orion nebula, taken under the seeing conditions of 0.2 inch-0.5 inch, cover the area of 5 by 5 feet centered on the Trapezium cluster, revealing details of the BN/KL region, the bright bar, and other conspicuous features as well as several new H₂ emission sources. There are more than 500 stars detected; most of them are not visible in optical images and are embedded in the molecular cloud behind the nebula. Their K'-band luminosity function confirmed the bump around 12 mag with a tail toward the fainter end of 17 mag. Some of these most faint stars may be good candidates for young brown dwarfs. The J-band image of L1551 IRS 5 revealed a pair of twisted jets emanating possibly from each of the binary protostars. The two jets are spatially resolved for the first time from the ground, with wiggly and knotty appearance similar to the R-band image taken with the Hubble Space Telescope, suggesting that the appearance is intrinsic to them and is not caused due to the spatial variation of extinction. Successive grism spectroscopy proved that the jet emission predominantly arises from the (Fe II) lines.

The advent of the large effective apertures of the Keck telescopes has resulted in the determination with unprecedented accuracy of the mass functions and mass ratios of faint x-ray transients as well as constraining the main- sequence companion star parameters and producing images of the accretion disks around the black holes.

We present science results from the first four months of early operations of the Hobby-Eberly Telescope (HET). During this period the HET was used for science approximately two weeks per month centered on new moon. We discuss the types of science program that are bets suited to the unique nature of the HET and give examples of survey and synoptic observations that are on-going. The Marcario Low Resolution Spectrograph is the only facility instrument currently in service, so the science result from this instrument are emphasized. Future facility instruments are briefly discussed, along with a description of current HET performance.

The NIRSPEC Brown Dwarf Spectroscopic Survey is a project to obtain a consistent set of high-quality near-IR spectra for each spectral class and sub-class of low-mass and/or sub- stellar objects to provide a new data base for models of the atmosphere of brown dwarfs and extra-solar giant planets. Most of the current targets are L-dwarfs and T-dwarfs discovered by the 2MASS. The survey is begin performed with the recently-commissioned near-IR spectrometer, NIRSPEC, a 1-5 micrometers cryogenic spectrograph at the WM Keck Observatory on Mauna Kea, using resolving powers of R equals 2,500-25,000. Preliminary results for four sources, three L-dwarfs and one T-dwarf, are presented here. Spectra from 1.13-2.33 micrometers at an average resolution of R equals 2,500 illustrate the development of deep steam bands and the weakening of FeH through the L-sequence, and the emergence of methane bands in the T-dwarfs. Complex detail in the spectra are the result of blending of numerous unresolved molecular transitions.

Now that Jovian-mass extrasolar planets are being discovered using high-precision radial velocity techniques, it is important to focus large survey programs on questions relating to the origin and evolution of extra-solar planetary systems. We are particularly interested in how the characteristics of the planetary system depend on the mass of the central star. Do massive stars form massive planets, or does tidal truncation limit the size to which a planet can grow. What role does early dynamical evolution play in systems with various mass stars. Do low mass stars form fewer planets, or perhaps lower mass planets. The Hyades star cluster is an excellent place to seek answers to these questions. The Hyades is one of the nearest star clusters to the Sum, and it represents a sample of stars formed at the same epoch with a uniform heavy element abundance. We are using the Keck 1 telescope with its HIRES spectrograph to conduct a high-precision radial velocity survey of late-F through Mid-M Hyades dwarfs, in order to anser these questions. In this carefully selected sample, the dominant independent variable is the mass of the star. We are now in our fourth season of observing. We present result son a wide variety of stars of various masses, including some stars showing variations possibly indicative of Jovian-mass companions.

Short-period giant extrasolar planets may be detected through Doppler-modulated IR spectroscopy. This paper presents an introduction of this technique and observational prospects.

SINFONI, the SINgle Faint Object Near-IR Investigation, is an instrument for the very large telescope (VLT), which will start its operation mid 2002 and allow for the first time near IR integral field spectroscopy at the diffraction limit of an 8-m telescope. SINFONI is the combination of two state-of-the-art instruments, the integral field spectrometer SPIFFI, built by the Max-Planck-Institut fuer extraterrestrische Physik, and the adaptive optics system MACAO, built by the ESO. It will allow a unique type of observations by delivering simultaneously high spatial resolution and a moderate spectral resolution, where the higher spectral resolution mode will allow for software OH suppression. This opens new prospects for astronomy.

The confluence of advances in telescope and spectrograph design computing power, pathfinding imaging capabilities on the ground and in space, and the maturity of many astrophysical fields, allow us to look beyond the study of a few unique objects and towards the systematic study of large samples in order to completely characterize their properties, formation history, and cosmological significance. These studies require spectroscopic observations to probe the kinematics, chemical composition, dynamics, ages, masses and evolutionary histories of astronomical objects. Examples of three fundamental science goals are described that demand a wide-field system on a large telescope.

In the report, the capability of detection of comets, similar comet of 1811 or comet Hole-Bopp in environs of other stars is considered. Recognizing that the maximum luminosity of a solar system comets is reached at a stream of a solar radiation apart approximately 1AU from the Sun, in the work the estimations of spacing intervals from comets up to stars around of which one they rotate are made. From the data about value of loss of a mass, the comet Hole-Bopp an estimation of influence gas-dusty cloud on transiting of irradiation of a star at transiting a similar comet between a star and Earth is made. Proceeding from a frequency of occurrence of the brightest comets of a solar system, in the paper quantity of comets reverting around of neighboring stars and quantity of comets, accessible to observation is evaluated. For stars located in environs about 20 parsecs from the Sun possible occurrence 5...6 large comets annually. As the Sun is a typical star of our Galaxy, the problem of existence for other stars of an own Oort cloud and capability of its detection is discussed.

Over the past few years, site-testing at the South Pole has revealed conditions that are uniquely favorable for IR astronomy. In particular, the exceptionally low sky brightness throughout the near- and mid-IR leads to the possibility of a modest-sized telescope achieving comparable sensitivity to that of existing 8-10 meter class telescopes. An 8m Antarctic telescope, if constructed, would yield performance that would be unrivaled until the advent of the NGST. In this paper we review the scientific potential of IR telescopes in Antarctica, and discuss their complementarity with existing 8-10m class telescopes.

All existing night-time astronomical telescopes, regardless of aperture, are blind to an important part of the universe - the region around bright objects. Technology now exist to build an unobscured 6.5 m aperture telescope which will attain coronagraphic sensitivity heretofore unachieved. A working group hosted by the University of Hawaii Institute for Astronomy has developed plans for a New Planetary Telescope which will permit astronomical observations which have never before ben possible. In its narrow-field mode the off-axis optical design, combined with adaptive optics, provides superb coronagraphic capabilities, and a very low thermal IR background. These make it ideal for studies of extra-solar planets and circumstellar discs, as well as for general IR astronomy. In its wide-field mode the NPT provides a 2 degree diameter field for surveys of Kuiper Belt Objects and Near-Earth Objects, surveys central to current intellectual interests in solar system astronomy.

Some highlights of high spectral resolution observations with large telescopes are presented. The focus is one the chemical composition of disk, halo, bulge, and local group objects. Examples are given of progress on the study of brown dwarfs. Several recent papers on the composition of cool stars in open clusters are summarized. Faint field stars in the Galactic halo have provided fertile ground for new research on the chemical history of the halo; some recent results are discussed. Individual stars in globular clusters from the turn-off to the top of the red giant branch have yielded new insights into stellar evolution and processes which occur in the interiors of these old stars. The echelle spectrum of a main sequence star in the Galactic bulge with V equals 19.8 has been obtained because of the effects microlensing on it. For the first time the composition of individual stars in several galaxies in our local group has been determined; this represents an important extension to our understanding of the chemical makeup to the universe.