Astrometric Data Research Articles

Transiting Exoplanet Yields for the Roman Galactic Bulge Time Domain Survey Predicted from Pixel-level Simulations

The Nancy Grace Roman Space Telescope (Roman) is NASA’s next astrophysics flagship mission, expected to launch in late 2026. As one of Roman’s core community science surveys, the Galactic Bulge Time Domain Survey (GBTDS) will collect photometric and astrometric data for over 100 million stars in the Galactic bulge in order to search for microlensing planets. To assess the potential with which Roman can detect exoplanets via transit, we developed and conducted pixel-level simulations of transiting planets in the GBTDS. From these simulations, we predict that Roman will find between ∼60,000 and ∼200,000 transiting planets—over an order of magnitude more planets than are currently known. While the majority of these planets will be giants (R p > 4R ⊕) on close-in orbits (a < 0.3 au), the yield also includes between ∼7000 and ∼12,000 small planets (R p < 4R ⊕). The yield for small planets depends sensitively on the observing cadence and season duration, with variations on the order of ∼10%–20% for modest changes in either parameter, but is generally insensitive to the trade between surveyed area and cadence given constant slew/settle times. These predictions depend sensitively on the Milky Way’s metallicity distribution function, highlighting an opportunity to significantly advance our understanding of exoplanet demographics, in particular across stellar populations and Galactic environments.

WD 0141−675: a case study on how to follow-up astrometric planet candidates around white dwarfs

ABSTRACT This work combines spectroscopic and photometric data of the polluted white dwarf WD 0141−675, which has a now retracted astrometric super-Jupiter candidate, and investigates the most promising ways to confirm Gaia astrometric planetary candidates and obtain follow-up data. Obtaining precise radial velocity measurements for white dwarfs is challenging due to their intrinsic faint magnitudes, lack of spectral absorption lines, and broad spectral features. However, dedicated radial velocity campaigns are capable of confirming close-in giant exoplanets (a few MJup) around polluted white dwarfs, where additional metal lines aid radial velocity measurements. Infrared emission from these giant exoplanets is shown to be detectable with JWST Mid-Infrared Instrument (MIRI) and will provide constraints on the formation of the planet. Using the initial Gaia astrometric solution for WD 0141−675 as a case study, if there were a planet with a 33.65 d period or less with a nearly edge-on orbit, (1) ground-based radial velocity monitoring limits the mass to &amp;lt;15.4 MJup, and (2) space-based infrared photometry shows a lack of infrared excess and in a cloud-free planetary cooling scenario, a substellar companion would have to be &amp;lt;16 MJup and be older than 3.7 Gyr. These results demonstrate how radial velocities and infrared photometry can probe the mass of the objects producing some of the astrometric signals, and rule out parts of the brown dwarf and planet mass parameter space. Therefore, combining astrometric data with spectroscopic and photometric data is crucial to both confirm and characterize astrometric planet candidates around white dwarfs.

Gaia uncovers difference in B and Be star binarity at small scales: evidence for mass transfer causing the Be phenomenon

ABSTRACT Be stars make up almost 20 per cent of the B star population, and are rapidly rotating stars surrounded by a disc; however the origin of this rotation remains unclear. Mass transfer within close binaries provides the leading hypothesis, with previous detections of stripped companions to Be stars supporting this. Here, we exploit the exquisite astrometric precision of Gaia to carry out the largest to date comparative study into the binarity of matched samples of nearby B and Be stars from the Bright Star Catalogue. By utilizing new ‘proper motion anomaly’ values, derived from Gaia DR2 and DR3 astrometric data alongside previous values calculated using Hipparcos and Gaia data, and the Gaia-provided RUWE, we demonstrate that we can identify unresolved binaries down to separations of 0.02 arcsec. Using these measures, we find that the binary fractions of B and Be stars are similar between 0.04 and 10 arcsec, but the Be binary fraction is significantly lower than that of the B stars for separations below 0.04 arcsec. As the separation range of these ‘missing’ binaries is too large for mass transfer, and stripped companions are not retrieved by these measures, we suggest the companions migrate inwards via binary hardening within a triple system. This confirms statistically for the first time the hypothesis that binary interaction causes the Be phenomenon, with migration causing the dearth of Be binaries between 0.02 and 0.04 arcsec. Furthermore, we suggest that triplicity plays a vital role in this migration, and thus in the formation of Be stars as a whole.

A DEEP STUDY OF THE OPEN CLUSTER NGC 5288 USING PHOTOMETRIC AND ASTROMETRIC DATA FROM GAIA DR3 AND 2MASS

This paper investigates a poorly studied open cluster, NGC 5288, using 2MASS JHKS and the recently released Gaia DR3 astrometric and photometric data. The mean proper motions in right ascension and declination are estimated as (-3.840 ± 0.230) and (-1.934 ± 0.162) mas yr-1 respectively. We also derive the age and distance of the cluster as 510 ± 190 Myr and 2.64 ± 0.11 kpc, using color-magnitude diagrams (CMDs). We also obtain the distance as 2.77 ± 0.42 kpc using the parallax method. Interstellar reddening E(B ‒ V) in the direction of the cluster is determined as 0.45 mag using the ((J ‒ H), (J ‒ K)) color-color diagram. We find the mass function slope for main-sequence stars as 1.39 ± 0.29 within the mass range 1.0-2.7 M☉, which agrees with Salpeter's value within the uncertainty. Galactic orbits are derived using the Galactic potential model, indicating that NGC 5288 follows a circular path around the Galactic center.

A Reanalysis of the Isolated Black Hole Candidate OGLE-2011-BLG-0462/MOA-2011-BLG-191

There are expected to be ∼108 isolated black holes (BHs) in the Milky Way. OGLE-2011-BLG-0462/MOA-2011-BLG-191 (OB110462) is the only such BH with a mass measurement to date. However, its mass is disputed: Lam et al. measured a lower mass of 1.6–4.4 M ⊙, while Sahu et al. and Mróz et al. measured a higher mass of 5.8–8.7 M ⊙. We reanalyze OB110462, including new data from the Hubble Space Telescope (HST) and rereduced Optical Gravitational Lensing Experiment (OGLE) photometry. We also rereduce and reanalyze the HST data set with newly available software. We find significantly different (∼1 mas) HST astrometry than Lam et al. in the unmagnified epochs due to the amount of positional bias induced by a bright star ∼0.″4 from OB110462. After modeling the updated photometric and astrometric data sets, we find the lens of OB110462 is a BH. Future observations with the Nancy Grace Roman Space Telescope, which will have an astrometric precision comparable or better to HST but a field of view 100× larger, will be able to measure hundreds of isolated BH masses via microlensing. This will enable the measurement of the BH mass distribution and improve understanding of massive stellar evolution and BH formation channels.

A Catalog of New Slowly Pulsating B-type Stars

This paper reports the discovery of new slowly pulsating B-type stars. Based on the photometric, spectral, and astrometric data of the TESS, LAMOST, and Gaia surveys, we have found 286 new slowly pulsating B-type (SPB) stars and 21 candidates. Among these, 20 are Be stars or candidates with emission-line profiles. It is shown that these SPB stars have luminosities between 40 and 2850 L ⊙ and effective temperatures ranging from 10,000 to 21,000 K. Their pulsation periods are from 0.14 to 6.5 days with amplitude ranges of 0.2–20 mmag in the TESS band. It is indicated that these targets follow the distribution of the SPB stars in the period–luminosity and the period–temperature diagrams. Their positions on the H-R diagram reveal that most of these pulsators are distributed in the instability region of SPB stars, in the main-sequence evolutionary stage, and with mass ranges of 2.5–7 M ⊙. However, there are some targets beyond the red edge of the theoretical instability region, which should be caused by the rapid rotation reducing the measured effective temperature. The discovery of these new SPB stars increases the total number by over 60%, which are significant samples for further investigating the structure and evolution of intermediate-mass and even massive stars by asteroseismology.

Age Distribution of Exoplanet Host Stars: Chemical and Kinematic Age Proxies from GAIA DR3

The GAIA space mission is impacting astronomy in many significant ways by providing a uniform, homogeneous, and precise data set for over 1 billion stars and other celestial objects in the Milky Way and beyond. Exoplanet science has greatly benefited from the unprecedented accuracy of the stellar parameters obtained from GAIA. In this study, we combine photometric, astrometric, and spectroscopic data from the most recent Gaia DR3 to examine the kinematic and chemical age proxies for a large sample of 2611 exoplanets hosting stars whose parameters have been determined uniformly. Using spectroscopic data from the Radial Velocity Spectrometer on board GAIA, we show that stars hosting massive planets are metal-rich and α-poor in comparison to stars hosting small planets. The kinematic analysis of the sample reveals that stellar systems with small planets and those with giant planets differ in key aspects of galactic space velocity and orbital parameters, which are indicative of age. We find that the galactic orbital parameters have a statistically significant difference of 0.06 kpc for Z max and 0.03 for eccentricity, respectively. Furthermore, we estimated the stellar ages of the sample using the MIST-MESA isochrone models. The ages and their proxies for the planet-hosting stars indicate that the hosts of giant planetary systems are younger when compared to the population of stars harboring small planets. These age trends are also consistent with the chemical evolution of the galaxy and the formation of giant planets from the core-accretion process.

Constraining an Einstein-Maxwell-dilaton-axion black hole at the Galactic Center with the orbit of the S2 star

We derive new constraints on the dilaton parameter appearing in the spherically-symmetric black hole solution of Einstein-Maxwell-dilaton-axion gravity, by studying the geodesic motion of the S2 star in the Galactic Center. Einstein-Maxwell-dilaton-axion black holes represent a compelling alternative to the standard black hole paradigm in General Relativity. This theory emerges from the low energy effective action of the heterotic string theory and has been proven to predict peculiar observational features from the direct imaging of black hole shadows. At a fundamental level, Einstein-Maxwell-dilaton-axion includes additional electromagnetic, dilatonic and axionic fields coupled to the space-time metric. When considering charged non-rotating black hole solutions, the additional fields endow the metric with one extra parameter b, called dilaton parameter, that is theoretically bound to 0 < b < M. Using publicly available astrometric data for S2 we derive an upper bound on b ≲ 12M at 95% confidence level and we demonstrate that only including the measurement of the relativistic orbital precession for S2 is sufficient to reduce this bound to b ≲ 1.4M at the same confidence level. Additionally, using a mock data mimicking future observations of S2 with the GRAVITY interferometer, we show that improved astrometric precision can help further narrow down the allowed dilaton parameter range to b ≲ 0.033M after monitoring the S2 orbit for one and a half period.

Шаровые скопления в центральной области Млечного Пути. II. Частотный анализ орбит, построенных по данным Gaia EDR3

This work represents the second stage of research aimed at studying the influence of the bar on the orbital dynamics of globular clusters (Bajkova, Smirnov, and Bobylev, 2023). The orbits of 45 globular clusters in the central galactic region with a radius of 3.5 kpc have been analyzed by spectral dynamics methods in order to identify objects captured by the bar. Since the parameters of the bar of the Milky Way are known with a very large uncertainty, orbits were constructed and their frequency analysis was carried out with varying the mass, length and angular velocity of rotation of the bar in a wide range of values with a fairly dense grid. The orbits were integrated 2.5 billion years backward. As a result, globular clusters supporting the bar were identified for each set of bar parameters. To form the 6D phase space required for orbit integration, we used the most accurate astrometric data from the Gaia satellite (Vasiliev and Baumgardt, 2021), as well as new refined average distances to globular clusters (Baumgardt and Vasiliev, 2021).

2021 occultations and transits of Linus orbiting (22) Kalliope

Aims.The satellite Linus orbiting the main-belt asteroid (22) Kalliope exhibited mutual occultation and transit events in late 2021. A photometric campaign was organised and observations were undertaken by the TRAPPIST-South, SPECULOOS-Artemis, OWL-Net, and BOAO telescopes, with the goal to further constrain dynamical and photometric models of this sizeable asteroid-satellite system.Methods.Our dynamical model is sufficiently complex, featuring multipoles (up to the order ofℓ= 2), internal tides, and external tides. The model was constrained by astrometry (spanning 2001–2021), occultations, adaptive-optics imaging, and calibrated photometry, as well as relative photometry. Our photometric model was substantially improved. A new precise (&lt;0.1 mmag) light curve algorithm was implemented, based on polygon intersections, which are computed exactly by including partial eclipses and partial visibility of polygons. Moreover, we implemented a ‘cliptracing’ algorithm, again based on polygon intersections, in which partial contributions to individual pixels are computed exactly. Both synthetic light curves and synthetic images then become very smooth.Results.Based on our combined solution, we confirmed the size of Linus, namely, (28 ± 1)km. However, this solution exhibits some tension among the light curves and the PISCO speckle-interferometry dataset, acquired simultaneously with the 2021 events. This indicates that improvements of the shape are still possible. In most solutions, Linus is darker than Kalliope, with the single-scattering albedosAw= 0.40 vs. 0.44. This is confirmed on deconvolved images. A detailed revision of astrometric data has allowed us to revise also theJ2≡ −C20value of Kalliope. Most importantly, a homogeneous body is excluded. For a differentiated body, two solutions exist: low-oblateness (C20≃ −0.12), with a spherical iron core, and, alternatively, high-oblateness (C20≃ −0.22) with an elongated iron core. These values correspond, respectively, to the low- and high-energy collisions we studied via SPH simulations in our previous work.

Astrophysical Parameters of the Open Cluster NGC 2509

This study presents structural and fundamental astrophysical parameters of poorly studied open cluster NGC 2509. We used the third photometric and astrometric data release of the Gaia (Gaia DR3) to perform analyses. By taking into account the Gaia DR3 astrometric data, we calculated the membership probabilities of the stars in the region of NGC 2509. As a result of the membership analysis, 244 stars with membership probabilities P  50% were determined as the physical members of the cluster. The colour excess, distance and age were obtained simultaneously by fitting solar metallicity PARSEC isochrones to G×GBP-GRP colour-magnitude diagram. We considered the most likely cluster member stars during the fitting procedure and calculated the colour excess, distance and age of the NGC 2509 as E(GBP-GRP) = 0.100±0.184 mag, d = 2518±667 pc and t = 1.5±0.1 Gyr, respectively.

Gaia search for stellar companions of TESS Objects of Interest IV

We present the latest results of our ongoing multiplicity study of (Community) TESS Objects of Interest, using astrometric and photometric data from the ESA‐Gaia mission to detect stellar companions of these stars and characterize their properties. A total of 134 binary, 6 hierarchical triple, and two quadruple star systems are identified among 1106 targets whose multiplicity is investigated in the course of our survey, located at distances closer than about 500 pc around the Sun. The detected companions and targets are at the same distance and have a common proper motion, as expected for components of gravitationally bound stellar systems, as demonstrated by their accurate Gaia DR3 astrometry. The companions have masses from about 0.11 to 2 and are most abundant in the mass range between 0.2 and 0.5 . The companions have projected separations from the targets between about 50 and 9700 au. Their frequency is the highest and constant from about 300 up to 750 au, decreasing at larger projected separations. In addition to main sequence stars, four white dwarf companions are detected in this study, whose true nature is revealed by their photometric properties.

Analytic Post-Newtonian Astrometric and Spectroscopic Models of Orbits around Black Holes

Observations of the S stars, the cluster of young stars in the inner 0.1 pc of the Galactic center, have been crucial in providing conclusive evidence for a supermassive black hole at the center of our galaxy. Since some of the stars have orbits less than that of a typical human lifetime, it is possible to observe multiple orbits and test the weak-field regime of general relativity. Current calculations of orbits require relatively slow and expensive computations in order to perform numerical integrations for the position and momentum of each star at each observing time. In this paper, we present a computationally efficient, first-order post-Newtonian model for the astrometric and spectroscopic data gathered for the S stars. We find that future, 30 m class telescopes—and potentially even current large telescopes with very high spectroscopic resolution—may be able to detect the Shapiro effect for an S star in the next decade or so.

Cluster aggregates surrounding Pismis 5 in the Vela molecular ridge

Context. In the Gaia era, the precision of astrometric data is unprecedented. High-quality data make it easier to find more cluster aggregates and gather further confirmation of these open clusters. Aims. We use Gaia Data Release 3 (DR3) to redetermine the open clusters surrounding Pismis 5 in the Vela molecular ridge (VMR). We also investigate the basic properties of these clusters. Methods. We applied two clustering algorithms (STARGO and pyUPMASK) to identify the open-cluster members in five-dimensional space with α, δ, ϖ, μαcos δ, and μδ. Results. We identify eight open clusters surrounding Pismis 5 in the VMR. The open cluster QZ 1 is newly discovered. As a result of our investigation of the comprehensive properties of the clusters, we present one open binary cluster candidate (Alessi 43 and Collinder 197) and one triple open-cluster candidate (Pismis 5, Pismis 5A, and Pismis 5B). Conclusions. We identify binary and triple open-cluster candidates as potential primordial aggregates based on their similar age, position, and motion. According to kinematic speculations, the two aggregate candidates will gradually separate, and their interiors will slowly disintegrate.

Gaia colour-magnitude diagrams of young open clusters

Context. Automated analyses of Gaia astrometric data have led to the discovery of many new high-quality open cluster candidates. When a good determination of their parameters is available, these objects become excellent tools for investigating the properties of our Galaxy. Aims. We explore whether young open clusters can be readily identified from Gaia data alone by studying the properties of their Gaia colour-magnitude diagrams. We also want to compare the results of a traditional cluster analysis with those of automated methods. Methods. We selected three young open cluster candidates from the UBC catalogue, ranging from a well-populated object with a well-defined sequence to a poorly populated and poorly defined candidate. We obtained classification spectra for the brightest stars in each. We redetermined members based on EDR3 data and fitted isochrones to derive the age, distance, and reddening. Results. All three candidates are real clusters with ages below 100 Ma. UBC 103 is a moderately populous cluster, with an age around 70 Ma. At a distance of ∼3 kpc, it forms a binary cluster with nearby NGC 6683. UBC 114 is a relatively proximal (∼1.5 kpc) poorly populated cluster containing two early-B stars. UBC 587 is a dispersed and very young (≤10 Ma) cluster located at ∼3 kpc, behind the Cygnus X region, which may be a valuable tracer of the Orion arm. Conclusions. The OCfinder methodology for the identification of new open clusters is extremely effective, with even poor candidates resulting in interesting detections. The presence of an almost vertical photometric sequence in the Gaia colour-magnitude diagram is a safe way to identify young open clusters. Automated methods for the determination of cluster properties give approximate solutions, but these are still subject to difficulties. There is some evidence suggesting that artificial intelligence systems may systematically underestimate extinction, which may impact in the age determination.

Astrophysical Parameters of the Open Cluster Berkeley 6

In this study, the structural and basic astrophysical parameters of poorly studied open cluster Berkeley 6 is calculated. Analyses of the cluster are carried out using the third photometric, spectroscopic and astrometric data release of Gaia (Gaia DR3). The membership probabilities of stars located through the cluster region are calculated by considering their astrometric data. Thus, we identified 119 physical members for Berkeley 6. The colour excess, distance and age of the cluster are determined simultaneously on the colour-magnitude diagram. We fitted solar metallicity PARSEC isochrones to the colour-magnitude diagram by considering the most probable member stars and obtained E(GBP-GRP) colour excess as 0.918±0.145 mag. Distance and age of the cluster are determined as d=2625±337 pc and t=350±50 Myr, respectively.

A unified exploration of the chronology of the Galaxy

ABSTRACT The Milky Way has distinct structural stellar components linked to its formation and subsequent evolution, but disentangling them is non-trivial. With the recent availability of high-quality data for a large numbers of stars in the Milky Way, it is a natural next step for research in the evolution of the Galaxy to perform automated explorations with unsupervised methods of the structures hidden in the combination of large-scale spectroscopic, astrometric, and asteroseismic data sets. We determine precise stellar properties for 21 076 red giants, mainly spanning 2–15 kpc in Galactocentric radii, making it the largest sample of red giants with measured asteroseismic ages available to date. We explore the nature of different stellar structures in the Galactic disc by using Gaussian mixture models as an unsupervised clustering method to find substructure in the combined chemical, kinematic, and age subspace. The best-fitting mixture model yields four distinct physical Galactic components in the stellar disc: the thin disc, the kinematically heated thin disc, the thick disc, and the stellar halo. We find hints of an age asymmetry between the Northern and Southern hemisphere, and we measure the vertical and radial age gradient of the Galactic disc using the asteroseismic ages extended to further distances than previous studies.

The variable stars in the field of NGC 6139: a critical approach to their reddening and membership

ABSTRACT We present a CCD VI time-series analysis of the globular cluster NGC 6139 and its variable star population. Using the astrometric data available in Gaia-DR3, we performed a membership analysis that enabled the construction of a clean colour–magnitude diagram (CMD). Variable stars in the field of the cluster reported by Gaia-DR3 and newly discovered ones in this paper are classified and their membership is critically evaluated. We report two cluster members RRc (V12, V15) and four SR (V13, V14, V17, V18) not previously detected and assign variable names to V11 and V16 detected by Gaia as they proof to be cluster members. Light curves and periods for non-member Gaia eclipsing binaries, semiregular variables, and newly detected RR Lyrae stars are provided. Fourier decomposition of the light curves of the cluster member RRab and RRc stars leads to the values [Fe/H] = −1.63 dex, and distance of 9.63 ± 0.68 kpc. The Oosterhoff type II nature of the cluster is confirmed. We adopted the mean reddening E(B − V) = 0.786 mag and performed a differential reddening analysis based on the dispersion of the red giant branch. The differential map allowed a mild correction of the CMD.

GaiaData Release 3

Context.The astrometric discovery of sub-stellar mass companions orbiting stars is exceedingly hard due to the required sub-milliarcsecond precision, limiting the application of this technique to only a few instruments on a target-per-target basis and to the global astrometry space missions HIPPARCOSandGaia. The thirdGaiadata release (GaiaDR3) includes the firstGaiaastrometric orbital solutions whose sensitivity in terms of estimated companion mass extends down to the planetary-mass regime.Aims.We present the contribution of the exoplanet pipeline to theGaiaDR3 sample of astrometric orbital solutions by describing the methods used for fitting the orbits, the identification of significant solutions, and their validation. We then present an overview of the statistical properties of the solution parameters.Methods.Using both a Markov chain Monte Carlo and a genetic algorithm, we fitted the 34 months ofGaiaDR3 astrometric time series with a single Keplerian astrometric-orbit model that had 12 free parameters and an additional jitter term, and retained the solutions with the lowestχ2. Verification and validation steps were taken using significance tests, internal consistency checks using theGaiaradial velocity measurements (when available), as well as literature radial velocity and astrometric data, leading to a subset of candidates that were labelled “validated”.Results.We determined astrometric-orbit solutions for 1162 sources, and 198 solutions were assigned the “Validated” label. Precise companion-mass estimates require external information and are presented elsewhere. To broadly categorise the different mass regimes in this paper, we use the pseudo-companion massM̃cassuming a solar-mass host and define three solution groups: 17 (9 validated) solutions with companions in the planetary-mass regime (M̃c&lt; 20MJ), 52 (29 validated) in the brown dwarf regime (20MJ≤M̃c≤ 120 MJ), and 1093 (160 validated) in the low-mass stellar companion regime (M̃c&gt; 120MJ). From internal and external verification and validation, we estimate the level of spurious and incorrect solutions in our sample to be ∼5% and ∼10% in the ‘OrbitalAlternative’ and ‘OrbitalTargetedSearch’ candidate sample, respectively.Conclusions.We demonstrate thatGaiais able to confirm and sometimes refine the orbits of known orbital companions and to identify new candidates, providing us with a positive outlook for the expected harvest from the full mission data in future data releases.

GaiaData Release 3

Context.The thirdGaiadata release (DR3) provides a wealth of new data products. The early part of the release,GaiaEDR3, already provided the astrometric and photometric data for nearly two billion sources. The full release now adds improved parameters compared toGaiaDR2 for radial velocities, astrophysical parameters, variability information, light curves, and orbits for Solar System objects. The improvements are in terms of the number of sources, the variety of parameter information, precision, and accuracy. For the first time,GaiaDR3 also provides a sample of spectrophotometry and spectra obtained with the Radial Velocity Spectrometer, binary star solutions, and a characterisation of extragalactic object candidates.Aims.Before the publication of the catalogue, these data have undergone a dedicated transversal validation process. The aim of this paper is to highlight limitations of the data that were found during this process and to provide recommendations for the usage of the catalogue.Methods.The validation was obtained through a statistical analysis of the data, a confirmation of the internal consistency of different products, and a comparison of the values to external data or models.Results.GaiaDR3 is a new major step forward in terms of the number, diversity, precision, and accuracy of theGaiaproducts. As always in such a large and complex catalogue, however, issues and limitations have also been found. Detailed examples of the scientific quality of theGaiaDR3 release can be found in the accompanying data-processing papers as well as in the performance verification papers. Here we focus only on the caveats that the user should be aware of to scientifically exploit the data.