He has published more than 550 papers in peer reviewed journals, yielding an H-index of 85, with more than 27.000 citations.[1]
His non refereed publications include 18 papers in 'The Messenger' [2](ESO) since 1995, such as 'Behind the Scenes of the Discovery of Two Extrasolar Planets: ESO Large Programme 666' [3] dedicated to the hunt of sub-stellar objects (exoplanets and brown dwarfs), stretching the limits of what was possible with the VLT by 2006, started the planet hunting for many promising candidates from OGLE. 76 publications on the American Astronomical Society, (1992 to 2014),[4] 43 Telegrams on The Astronomer's Telegram (2006–2021),[5] 37 publications on the Astronomical Society of the Pacific Conference Series,[6] 34 Proceedings of the International Astronomical Union [7] such as 'Stellar variability in the VVV survey: overview and first results' 2014,[8] 'Massive infrared clusters in the Milky Way' 2017,[9] 'The SuperMACHO Microlensing Survey' 2005 Proceedings of the International Astronomical Union, Volume 2004 , Issue IAUS225 , July 2004, pp.357 – 362.[10]
He also has written books for the general public such as 'Mundos Lejanos' (Ediciones B Chile, 2007 ISBN 9563040392, 9789563040395), 'Vistas de la Galaxia' along with Joyce Pullen and Ignacio Toledo [11][12] and 'Nuevos Mundos' along with Juan José Clariá (ISBN 9789876022941), in addition to editing a number of specialised books. He is active in outreach activities, such as public talks and press interviews.
Early life and education
Dante spent his childhood in Santa Fe,[citation needed] Argentina where he was born. He attended school at the Escuela Provincial No. 19 and his summer holidays were spent at the grandparent's house in San Javier,[citation needed] a nearby village where his great grandfather Angelo Minniti, settled at the beginnings of the XX th century, coming originally from Guardavalle,[citation needed] Provinzia di Catanzaro, Italy.
His undergraduate studies were done at Universidad Nacional de Córdoba, Argentina,[citation needed] where he obtained his Licenciatura degree and started a long-life collaboration with Professor Juan José Clariá. In 1986 he attended the first Vatican Observatory Summer School (VOSS) at Castel Gandolfo, Vatican State. The school was about 'The Structure and Dynamics of Galaxies', with lectures from Vera Rubin, Martin McCarthy and Dave Latham.[13]
In 1988 with the mentorship of Fr. George Coyne and the support of the Vatican Observatory, he obtained the first 'Father Martin McCarthy' scholarship to carry out his graduate studies at the Department of Astronomy and Steward Observatory of the University of Arizona, where he obtained his PhD in 1993 with his thesis work on 'Kinematics and stellar populations of the galactic bulge' [14] with Profs. Edward Olszewski, Jim Liebert and Simon White as doctoral advisors.
Minniti obtained another PhD at the Universidad Nacional de Córdoba, Argentina in 1998, working on "Metal Poor Globular Clusters in the Milky Way" with Prof. Juan José Clariá as supervisor. Between 1993 and 1996, he obtained an ESO postdoctoral fellowship at the European Southern Observatory in Garching, Germany [15] and then from the end of 1996 to 1999 an IGPP Fellowship at the Lawrence Livermore National Laboratory (Livermore, California, USA).[16]
In 1998 he moved to Chile as Professor at the Pontifical Catholic University of Chile, where he became Full Professor and Director of Research and Doctorate (2010–2012), then in 2014 he was invited to create the Doctoral Program on Astrophysics at Universidad Andrés Bello where he is Full Professor and Director of the Institute of Astrophysics.[17]
He served (2019–2021) as president of IAU Commission H1 'The Local Universe', where he is still an active member, as well as member of Division B: Facilities, Technologies and Data Science, Division F: Planetary Systems and Astrobiology, Division H: Interstellar Matter and Local Universe, Division B: WG Time Domain Astronomy, as well as past affiliations to 27 divisions or commissions since 2003 and IAU member since 1994.[22]
Other memberships:
· Sociedad Chilena de Astronomía, founding member, 2000–present.[23]
· Asociación Argentina de Astronomía, member since 1985.
He has served on numerous scientific committees, including the ESO Scientific and Technology Committee, the ESO Observing Proposals Committee, and the Gemini International Telescope Allocation Committee. He has been referee for major Astronomy journals and national and international funding organizations.
Research
From his early career, he has worked on the structure of galaxies, stellar populations, variable stars, microlensing events, globular cluster evolution, the Milky Way structure and dynamics, exoplanets, and astrobiology.
In the Milky Way he has studied the ages of stellar populations, the evolution of globular clusters, the stellar initial mass function, variable stars such as RR Lyrae, Cepheids and Miras, microlensing events, novae, and the unknown stellar objects named WITs (What Is This?) (Minniti et al. 2019, Lucas et al. 2020, Saito et al. 2021, Smith et al. 2021 [25]).
Early years
From his experience at VOSS 1986 and his two PhD thesis (1993 and 1998), Minniti started his career as a professor (1998) with experience on kinematics and stellar populations of the Milky Way and on metallicities of globular clusters that yielded on a particular interest in the composition, evolution, dynamics, and kinematics of our galaxy. These interests required tools such as metallicity, age and distance indicators, such as RR Lyrae, Cepheids and Miras in the context of smaller structures such as open and globular clusters, so Prof. Minniti started with a particular interest, our galaxy, and a broad set of knowledge that fostered investigation on adjacent topics such as microlensing with the SuperMACHO project and then with the VVV Survey, which also conveyed all his other interests.
Microlensing
As a follow-up of the MACHO project, SuperMACHO aim was to search for microlensing events towards the Large Magellanic Cloud using the CTIO 4m Blanco telescope and the MOSAIC imager (LMC) to identify the type of population that causes the excessive microlensing rate that the MACHO study observed. To evaluate the differential microlensing rate over the LMC face, SuperMACHO observation approach has been refined, discovering that while this derivative is highly discriminant between Galactic halo and LMC self-lensing, it is largely insensitive to the specifics of the LMC's internal structure. Real-time microlensing alerts and photometric and spectroscopic followup debuted in 2003, retrieving several dozen microlensing candidates with preliminary light curves and related data along with the many dozen microlensing candidates extracted. One observation is the belief that the SNe background behind the LMC is a significant contamination, similar to the MACHO project, and this background has not been eliminated from SuperMACHO single-color candidate sample. Finally, they tailored a follow-up method to distinguish between SNe and real microlensing.
With the VVV Survey data, while supervising Gabriela Navarro on her PhD thesis, they discovered more than 600 microlensing events on the galactic bulge plane on a span of 5 years of observations, with the different cadence of days between observations that had the disadvantage of losing some events of short time scale, but also letting the detection of long time scale events.[26]
Variability and Transcients
On variability, along with collaborator Roberto K. Saito, has named as 'WIT' (acronym for What is This) new kinds of variable stars or extreme transients that do not fit any known standards but indicate astronomical processes that cause variability of different nature, like large amplitude declines, or large-amplitude outbursts followed by apparently constant quiescent states. These sources faded nearly 7 magnitudes in one year and so on.
VVV-WIT-07 is a strange star with seemingly random brightness variations of unknown nature. Some variability aspects resemble the Boyjianian's star or a Mamajek's object, which are very rare, with proposed explanations ranging from eclipses by a cometary system or misaligned disks, to the presence of a Dyson sphere.[27][28]
VVV-WIT-08 exhibits another unexplained variability. This normal red giant star suffered a single episode with symmetric brightness change. The eclipse like episode does not fit any known phenomena, being too long and deep. The "giant that blinked" (coined by Leigh Smith) may be a distant red supergiant eclipsed by an inclined dust disk.[29]
With the VVV Survey, he has delivered catalogues of thousands of RR Lyrae, along them, a thousand on the Galactic Center. These are old and metal-poor Population II stars, demonstrating that the nuclear region of the Galaxy is very old.
Classical Cepheids trace the young and metal-rich Population I stars. They were able to detect them well beyond the galactic center (because the interstellar medium is more transparent to the infrared light), and they could trace the structure of the far side of the Milky Way.
Miras, very luminous distance indicators with long periods from 100 to 1000 days are also detectable with the 12 year baseline (more than 4000 days) of the VVV and VVVX observations.
Milky Way
Along the 3D structure traced by different age indicators such as RR Lyrae and Cepheids mainly, there was another structure to explore, that is the center of the galaxy composed by a bar and a bulge, first there was to tell if the bulge was an elliptical or peanut shape, then the size of the bar and if it was tilted, twisted or none. Then it was needed to judge how both components interact with each other.
Exoplanets and Astrobiology
On exoplanets and astrobiology he has contributed with the inspection and refinement of exoplanet detection methods such as radial velocities, the detection of GJ 832c, a super-Earth orbiting the edges of the habitable zone of GJ 832, the understanding of temperate planetary atmospheres and an interesting work with Valentin Ivanov and collaborators entitled 'A qualitative classification of extraterrestrial civilizations' [30] intended to the improve the design of strategies for the search of extraterrestrial civilizations.
Research with VVV/VVVX Survey
Being the P.I. of the VVV Survey and eXtended version VVVX along with fostering new scientists as PhDs, Dante had the opportunity to develop his research on every aspect of the scientific goals of the VVV and VVVX, publishing more than 160 papers on discoveries and development about subjects such as Variable Stars, Extinction Law, Open Clusters, Globular Clusters, Photometric and astrometric catalogues, Milky Way structure (spiral structure, arms, disk, bulge, bar), big data, automated tools for detecting certain sets of objects, analysis of physical processes on different objects such as YSOs, WITs, assessing stellar populations, analysis of survival on the extreme environment like the galactic center, near-IR catalogues of over 2 x 10^9 sources from which 10^7 are variable.
VVV also contributed to extragalactic astronomy by completing the census for galaxies beyond the bulge and southern disk of the Milky Way and even detecting an overdensity of galaxies.[31]
The VVV Survey and Extended Version VVVX
By 2006, The European Southern Observatory made a call for public survey proposals for the newcomer telescope VISTA (Visible and Infrared Survey Telescope for Astronomy) [32] and it's infrared instrument VIRCAM (VISTA Infrared Camera).[33]
Prof. Minniti's proposal was the observation of variability in the Milky Way Bulge and Prof. Philip Lucas,[34] a British astronomer working with UKIDSS,[35] a similar telescope as VISTA but based at the summit of Mauna Kea in Hawaii, that had been observing the northern disk of the Milky Way submitted his proposal for this ESO call consisting on an analogous survey for the southern disk of the Milky Way. Both science goals were very similar, so ESO encouraged Dante and Phil to team up with a unified proposal for the Bulge and Southern Disk of the Milky Way, which resulted on the VVV Survey and was awarded a total of 1929 hours of observation in 192 nights over the lapse of 5 years and upon 520 sq. deg.
The VISTA telescope was on the making and was due to begin operations in 2010, when observations finally begun. The total number of hours executed were 2205.[36]
The Milky Way bulge and a nearby region of the mid-plane, where star formation activity is intense, began being scanned by the public ESO near-IR variability survey 'Vista Variables in the Via Lactea' (VVV) in 2010, mapping repeatedly most of the Milky Way bulge, as well as the inner southern disk.[37] One of the science objectives was using RR Lyrae stars, well-known distance markers, to construct a three-dimensional map of the Bulge.
A total of 33 known globular clusters and 350 open clusters were included in the initial target lists of observations with the 4-m VISTA telescope at ESO Paranal, over five years (2010–2014), covering 10^9 point sources over a region of 540 sq. deg. A deep near-IR atlas with five passbands (0.9-2.5 microns on the Z, Y, J, H, Ks bands) and a list of more than 10^6 variable point sources was the planned result. The VVV variable star survey would allow the development of a 3-D map of the investigated region using well-understood distance markers, such as Cepheids and RR Lyrae stars, in contrast to single-epoch surveys, which typically produce 2-D maps. VVV provided crucial data on the populations' ages. For a thorough knowledge of the variable sources in the inner Milky Way, the observations were integrated with data from MACHO, OGLE, EROS, HST, VST, Spitzer, Chandra, WISE, INTEGRAL, XMM-Newton, Fermi LAT, Gaia, and ALMA. Enabling additional research into the Milky Way's history, the evolution of its globular clusters, a population count of the Galactic Bulge and core, and an examination of the star-forming regions in the disk. The combined variable star catalogues are crucial for theoretical studies of the pulsation characteristics of stars.[38]
Data Access and Catalogs
The VVV Survey data products are public and provide an exciting new tool for the study of the structure, content, and star formation history of our Galaxy as well as for investigations of the recently discovered star clusters, star forming regions in the disk, high proper motion stars, asteroids, planetary nebulae, and other interesting objects. They also provide a unique dataset to map the stellar populations in the Galactic bulge and the adjacent southern plane.
VVV's open survey catalogues are made public and accessible to the entire community through the ESO archive [39] and through ESO Archive Science Portal,[40] under ESO programme ID 179.B-2002.
The VVV catalogues are also available through the University of Edinburgh's Institute for Astronomy's Wide Field Astronomy Unit (WFAU),[41] the Cambridge Astronomical Survey Unit (CASU) [42] and at the Centre de Données astronomiques de Strasbourg (CDS) through VIZIER [43] and through ALADIN desktop application.[44]
An Ongoing Survey, The VVVX
In 2015, at the verge of the end of VVV observations, Prof. Minniti called for a meeting at The Vatican Observatory, Castelgandolfo, Vatican State; named 'Vatican VVV Workshop' from 19 to 21 May 2015.[45] The aim was to design a new proposal that would yield further knowledge of the Milky Way due to the extension of commission of the VIRCAM. The output was a proposal for observing a broader area around the original VVV observing area of 1.700 sq. deg. (4% of the sky).
The proposal was submitted to ESO and advocated at the meeting "Rainbows on the Southern Sky: science and legacy value of the ESO Public Surveys and Large Programmes" at ESO Garching, from October 5 to 9th, 2015.[46] On about five talks the legacy, the main results and the ongoing investigations of the VVV Survey were presented and the forecoming science that were to be reached if the eXtended VVV Survey (VVVX) proposal was accepted. Finally, the VVVX was granted 2000 hours of observation on an area of about 1700 sq. deg. consisting of 1028 VIRCAM 'tiles' [47](a tile is an area of 1.5 square degrees on the sky covered by a single observation). The observations were restricted from the original five VVV Survey passbands in the infrared (Z, Y, J, H, Ks) to three bands (J, H, Ks) for deeper observations and to optimize the multi-epoch observations. The VVVX observations were conducted from 2016 to early 2023 and the total hours of observation executed were about 4.000.
The VIRCAM in being replaced by 4MOST spectroscopic survey instrument [48] starting in 2023.
VVV and VVVX Legacy
The VVV Survey and its extended version, the VVVX, since the first proposal submission to the final data release (which will be two years before the end of observations in October 2022) will have lasted 18 years (2006 to 2024), with 14 years of observations (2010 to 2023).
By mid-2023 there are 260 refereed papers from members of The VVV Science Team [49] and 70 referred papers from authors outside The VVV Science Team [50] and more than 300 non-refereed papers from authors both within and outside the VVV Science Team.[51]
By the end of 2023, 15 graduate students obtained their PhD, and 10 graduate students obtained their MsC, with theses based on VVV/VVVX Survey observations.[52]
The catalogues published by ESO at present (2022) are
VVV/VIRAC: proper motion catalog
VVV: Catalogue of Variables in the Via Lactea
VVV: Multi-Epoch Ks-Band Photometry in the Via Lactea
VVV: ZYJHKs Catalogue in the Via Lactea
And data releases:
DR1 until October 2010
DR2 until October 2011
DR3 until October 2013
DR4 until October 2015
Related Research Articles
A globular cluster is a spheroidal conglomeration of stars that is bound together by gravity, with a higher concentration of stars towards their centers. They can contain anywhere from tens of thousands to many millions of member stars, all orbiting in a stable, compact formation. Globular clusters are similar in form to dwarf spheroidal galaxies, and the distinction between the two is not always clear. Their name is derived from Latin globulus. Globular clusters are occasionally known simply as "globulars".
Star clusters are large groups of stars held together by self-gravitation. Two main types of star clusters can be distinguished: globular clusters are tight groups of ten thousand to millions of old stars which are gravitationally bound, while open clusters are more loosely clustered groups of stars, generally containing fewer than a few hundred members, and are often very young. Open clusters become disrupted over time by the gravitational influence of giant molecular clouds as they move through the galaxy, but cluster members will continue to move in broadly the same direction through space even though they are no longer gravitationally bound; they are then known as a stellar association, sometimes also referred to as a moving group.
Galactic astronomy is the study of the Milky Way galaxy and all its contents. This is in contrast to extragalactic astronomy, which is the study of everything outside our galaxy, including all other galaxies.
Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work The Realm of the Nebulae and, as such, form part of the Hubble sequence. Most spiral galaxies consist of a flat, rotating disk containing stars, gas and dust, and a central concentration of stars known as the bulge. These are often surrounded by a much fainter halo of stars, many of which reside in globular clusters.
RR Lyrae variables are periodic variable stars, commonly found in globular clusters. They are used as standard candles to measure (extra) galactic distances, assisting with the cosmic distance ladder. This class is named after the prototype and brightest example, RR Lyrae.
Messier 107 or M107, also known as NGC 6171, is a very loose globular cluster in a very mildly southern part of the sky close to the equator in Ophiuchus, and is the last such object in the Messier Catalogue.
The Galactic Center is the rotational center and the barycenter of the Milky Way. Its central massive object is a supermassive black hole of about 4 million solar masses, which is called Sagittarius A*, a compact radio source which is almost exactly at the galactic rotational center. The Galactic Center is approximately 8 kiloparsecs (26,000 ly) away from Earth in the direction of the constellations Sagittarius, Ophiuchus, and Scorpius, where the Milky Way appears brightest, visually close to the Butterfly Cluster (M6) or the star Shaula, south to the Pipe Nebula.
In astronomy, a galactic bulge is a tightly packed group of stars within a larger star formation. The term almost exclusively refers to the central group of stars found in most spiral galaxies. Bulges were historically thought to be elliptical galaxies that happened to have a disk of stars around them, but high-resolution images using the Hubble Space Telescope have revealed that many bulges lie at the heart of a spiral galaxy. It is now thought that there are at least two types of bulges: bulges that are like ellipticals and bulges that are like spiral galaxies.
The Sagittarius Dwarf Spheroidal Galaxy (Sgr dSph), also known as the Sagittarius Dwarf Elliptical Galaxy, is an elliptical loop-shaped satellite galaxy of the Milky Way. It contains four globular clusters in its main body, with the brightest of them—NGC 6715 (M54)—being known well before the discovery of the galaxy itself in 1994. Sgr dSph is roughly 10,000 light-years in diameter, and is currently about 70,000 light-years from Earth, travelling in a polar orbit at a distance of about 50,000 light-years from the core of the Milky Way. In its looping, spiraling path, it has passed through the plane of the Milky Way several times in the past. In 2018 the Gaia project of the European Space Agency showed that Sgr dSph had caused perturbations in a set of stars near the Milky Way's core, causing unexpected rippling movements of the stars triggered when it moved past the Milky Way between 300 and 900 million years ago.
Messier 2 or M2 is a globular cluster in the constellation Aquarius, five degrees north of the star Beta Aquarii. It was discovered by Jean-Dominique Maraldi in 1746, and is one of the largest known globular clusters.
The Canis Major Overdensity or Canis Major Dwarf Galaxy is a disputed dwarf irregular galaxy in the Local Group, located in the same part of the sky as the constellation Canis Major.
Gravitational microlensing is an astronomical phenomenon due to the gravitational lens effect. It can be used to detect objects that range from the mass of a planet to the mass of a star, regardless of the light they emit. Typically, astronomers can only detect bright objects that emit much light (stars) or large objects that block background light. These objects make up only a minor portion of the mass of a galaxy. Microlensing allows the study of objects that emit little or no light.
NGC 4565 is an edge-on spiral galaxy about 30 to 50 million light-years away in the constellation Coma Berenices. It lies close to the North Galactic Pole and has a visual magnitude of approximately 10. It is known as the Needle Galaxy for its narrow profile. First recorded in 1785 by William Herschel, it is a prominent example of an edge-on spiral galaxy.
Terzan 5 is a heavily obscured globular cluster belonging to the bulge of the Milky Way galaxy. It was one of six globulars discovered by French astronomer Agop Terzan in 1968 and was initially labeled Terzan 11. The cluster was cataloged by the Two-Micron Sky Survey as IRC–20385. It is situated in the Sagittarius constellation in the direction of the Milky Way's center. Terzan 5 probably follows an unknown complicated orbit around the center of the galaxy, but currently it is moving towards the Sun with a speed of around 90 km/s.
VISTA Variables in the Via Lactea –TheVVV Survey– is observing the Milky Way's bulge and southern disk in the near-infrared using the capabilities of the VISTA Telescope at Paranal, Chile.
The VVV Survey is an ESO public survey scanning the Milky Way bulge and adjacent section of the southern mid-plane in the near-infrared. This area, is active in star formation and very rich in dust and interstellar gas, which makes it impossible to see through in the visible as the extinction and crowding are high. There are though, some ‘clear windows’ thought the whole survey area, where optical surveys can be carried out, like MACHO, OGLE and EROS.
NGC 121 is a globular cluster of stars in the southern constellation of Tucana. It is the oldest globular cluster in the Small Magellanic Cloud (SMC), which is a dwarf satellite galaxy of the Milky Way. This cluster was first discovered by English astronomer John Herschel on September 20, 1835. The compiler of the New General Catalogue, Danish astronomer John Louis Emil Dreyer, described this object as "pretty bright, pretty small, little extended, very gradually brighter middle". The cluster is located at a distance of around 200,000 light-years (60 kpc) from the Sun.
Georges Meylan is a Swiss astronomer, born on July 31, 1950, in Lausanne, Switzerland. He was the director of the Laboratory of Astrophysics of the Swiss Federal Institute of Technology (EPFL) in Lausanne, Switzerland, and now a professor emeritus of astrophysics and cosmology at EPFL. He is still active in both research and teaching.
NGC 1380 is a lenticular galaxy located in the constellation Fornax. It is located at a distance of circa 60 million light years from Earth, which, given its apparent dimensions, means that NGC 1380 is about 85,000 light years across. It was discovered by James Dunlop on September 2, 1826. It is a member of the Fornax Cluster.
↑ Becker, Andrew C.; Rest, A.; Stubbs, C.; Miknaitis, G. A.; Miceli, A.; Covarrubias, R.; Hawley, S. L.; Aguilera, C.; Smith, R. C.; Suntzeff, N. B.; Olsen, K.; Prieto, J. L.; Hiriart, R.; Garg, A.; Welch, D. L.; Cook, K. H.; Nikolaev, S.; Clocchiatti, A.; Minniti, D.; Keller, S. C.; Schmidt, B. P. (2004). "The SuperMACHO Microlensing Survey". Proceedings of the International Astronomical Union. 2004: 357–362. arXiv:astro-ph/0409167. doi:10.1017/S1743921305002164. S2CID18384591.
↑ Saito, R. K.; Minniti, D.; Ivanov, V. D.; Catelan, M.; Gran, F.; Baptista, R.; Angeloni, R.; Caceres, C.; Beamin, J. C. (2019). "VVV-WIT-07: Another Boyajian's star or a Mamajek's object?". Monthly Notices of the Royal Astronomical Society. 482 (4): 5000–5006. arXiv:1811.02265. doi:10.1093/mnras/sty3004.
↑ Mamajek, Eric E.; Quillen, Alice C.; Pecaut, Mark J.; Moolekamp, Fred; Scott, Erin L.; Kenworthy, Matthew A.; Cameron, Andrew Collier; Parley, Neil R. (2012). "Planetary Construction Zones in Occultation: Discovery of an Extrasolar Ring System Transiting a Young Sun-Like Star and Future Prospects for Detecting Eclipses by Circumsecondary and Circumplanetary Disks". The Astronomical Journal. 143 (3): 72. arXiv:1108.4070. Bibcode:2012AJ....143...72M. doi:10.1088/0004-6256/143/3/72. S2CID55818711.
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