Gaia DR2 was released in April 2018 and contains a photometric catalogue of more than 1 billion sources. This release contains colour information in the form of integrated BP and RP photometry in addition to the latest G-band photometry. The level of uncertainty can be as good as 2 mmag with some residual systematics at the 10 mmag level. The addition of colour information greatly enhances the value of the photometric data for the scientific community. A high level overview of the photometric processing, with a focus on the improvements with respect to Gaia DR1, was given. The definition of the Gaia photometric system, a crucial part of the calibration of the photometry, was also explained. Finally, some of the photometric improvements expected for the next data release were described.

I discuss the photometric calibration of the SkyMapper Southern Survey, our adopted methods and what we learned from comparisons with external catalogues.

Photometric passbands are usually characterised through laboratory measurements and once in operations they are refined with true observations of reference sources with known spectral energy distribution. This paper revises the methods to determine those passbands and discusses the limitations encountered. The passbands are not fully constrained by the reference sources used and the method presented here allows to evaluate which is the constrained and the unconstrained component of the passband.

We discovered stars that show spectra very close to the blackbody radiation without any line features. We found 17 such stars out of 0.8 million stellar objects in the SDSS archive. The blackbody temperature is approximately 104K. We identify these stars as DB white dwarfs with the helium atmosphere, possibly with a trace amount of hydrogen, that yields nearly perfect blackbody spectrum, which is also confirmed with our later study. These stars can be used to test the accuracy of the AB zero point across different colour bands, in particular including the NIR pass bands. The zero points of SDSS photometry are verified to < 0.01 mag.

The calibration hardware system of the Large Synoptic Survey Telescope (LSST) is designed to measure two quantities: a telescope’s instrumental response and atmospheric transmission, both as a function of wavelength. First of all, a “collimated beam projector” is designed to measure the instrumental response function by projecting monochromatic light through a mask and a collimating optic onto the telescope. During the measurement, the light level is monitored with a NIST-traceable photodiode. This method does not suffer from stray light effects or the reflections (known as ghosting) present when using a flat-field screen illumination, which has a systematic source of uncertainty from uncontrolled reflections. It allows for an independent measurement of the throughput of the telescope’s optical train as well as each filter’s transmission as a function of position on the primary mirror. Second, CALSPEC stars can be used as calibrated light sources to illuminate the atmosphere and measure its transmission. To measure the atmosphere’s transfer function, we use the telescope’s imager with a Ronchi grating in place of a filter to configure it as a low resolution slitless spectrograph. In this paper, we describe this calibration strategy, focusing on results from a prototype system at the Cerro Tololo Inter-American Observatory (CTIO) 0.9 meter telescope. We compare the instrumental throughput measurements to nominal values measured using a laboratory spectrophotometer, and we describe measurements of the atmosphere made via CALSPEC standard stars during the same run.

The medium-band Vilnius photometric system with the mean wavelengths at 345 (U), 374 (P), 405 (X), 466 (Y), 516 (Z), 544 (V), and 656 (S) nm for many years was an important tool to determine interstellar reddenings and distances of single stars due to its ability to classify stars of all temperatures in spectral classes and luminosity classes in the presence of different interstellar reddenings. At present, Gaia DR2 presents distances to stars with an unprecedented accuracy at least up to 3 kpc. However, multicolor photometry, which allows the classification of stars as well as the preliminary determination of stellar temperatures, gravities, metallicities and interstellar reddenings, remains an important method for distant stars. Here we present an empirical calibration of the intrinsic color indices of the Vilnius system in terms of physical parameters of stars for dwarf and giant stars of spectral classes F-G-K-M. In any attempted photometric determination of physical parameters of stars it is important to have an extensive and homogeneous sample of spectroscopically determined parameters for stars for which there are also accurate photometric data. As a source catalogue for the Vilnius photometry the latest updated version of the Catalogue of Photoelectric Observations in the Vilnius System was used, which contains compilations from the published photometry for about 11 000 stars. The stars which had both the Gaia DR2 parallaxes and the determinations of stellar parameters from high-dispersion spectra were extracted from this catalogue. The final sample contains more than 1500 stars of spectral classes F-M. The majority of these stars (ca 70%) are not reddened, for others the values of interstellar reddening AV were determined using the regular techniques of photometric classification in the Vilnius system. The absolute magnitudes MV and consequently the luminosity classes were determined using Gaia DR2 parallaxes. We present the analytical expressions for the effective temperature Teff and surface gravity logg and evaluate the errors of solutions for dwarf and giant stars. To test the accuracy of the proposed method, we have compared our results with the stars observed by Gaia and with the stellar parameters available from the large spectroscopic surveys: APOGEE, Gaia-ESO, GALAH, LAMOST, RAVE and SEGUE. The results of comparison contain 5-6 % outliers.

The proposed method allows the fast and straightforward evaluation of stellar physical parameters for the stars observed in the Vilnius photometric system. Despite the fact, that the accuracy of determination is significantly lower than in the case of spectroscopic methods, the method described may be useful for distant faint stars, which are still inaccessible for spectroscopic observations.

The UVIT ultraviolet and visual band detectors and electronics for the ASTROSAT observatory were calibrated in the vacuum laboratory at the University of Calgary. This work was supported by the Canadian Space Agengy and carried out prior to integration with the UVIT optical assembly and the ASTROSAT spacecraft. The multiband (X-ray, ultraviolet and optical) ASTROSAT observatory was successfully launched by the Indian Space Research Organization on Sept. 28, 2015, with subsequent in-orbit verification and ongoing calibration activities. Here we discuss the current issues of calibrating the UVIT data, such as distortion corrections, and how the laboratory data is being used to address these issues.

Color term corrections for magnitudes measured on the UVIS2 relative to the UVIS1 detector of the WFC3 camera on board Hubble Space Telescope are needed for three ultra-violet filters, namely F218W, F225W, and F275W. The two WFC3 detectors have different quantum efficiencies in the ultra-violet regime (λ < 4,000 Å), resulting in different count rate ratios as a function of the spectral type of the source. In the worst case, for cool red sources measured on UVIS2, there is a magnitude offset relative to UVIS1 up to ∼ 0.08 mag, while the offset is negligible for hot (Teff ≳ 30,000 K) blue sources.

Future facilities and deep surveys such as LSST, JWST and WFIRST, will require a network of standards faint enough to avoid saturation and homogenously distributed in both hemispheres. DA white dwarfs have almost pure hydrogen atmospheres and they are the simplest stars to model. The opacities are known from first principles, and for temperatures higher than ∼ 20,000 K, their photospheres are purely radiative and should be photometrically stable. DA white dwarfs are then the best candidates to establish a network of faint spectrophotometric standards. In order to provide standards in the dynamic range of large aperture (d > 4m) telescopes, we collected Hubble Space Telescope WFC3 images and ground-based spectroscopy for 23 DA white dwarfs fainter than r ∼ 16.5 mag, distributed at equatorial and northern latitudes (see Saha et al. in these conference proceedings).

SCALA is a physical calibration device for the SuperNova Integral Field Spectrograph (SNIFS), mounted to the University Hawaii 2.2m telescope on Mauna Kea. For type Ia supernova (SN Ia) cosmology programs, an improved fundamental calibration directly translates into improved cosmological constraints. The aim of SCALA is to perform a fundamental calibration of the CALSPEC (Bohlin 2014) standard stars, which are currently calibrated relative to white dwarf model atmospheres.

Section 1 of the FM14 focus on bridging the astronomy research and outreach communities - recent highlights, emerging collaborations, best practices and support structures. This paper also contains supplementary materials that point to contributed talks and poster presentations that can be found online.

The Virtual Observatory (VO) is an international astronomical community-based initiative. VO aims to allow global electronic access to the available astronomical data archives of space and ground-based observatories and other sky survey databases. VO for education is a project developed within the framework of the European Virtual Observatory (EuroVO) with the aim of diffusing VO data and software to the public, in particular students, teachers and astronomy enthusiasts. VO for education offers use cases, pedagogical units, and simplified professional software that will allow a taste of the emotion of scientific research even to those approaching astronomy for the first time or simply wishing to wander between stars.

Processing our increasingly large datasets poses a bottleneck for producing real scientific outcomes and citizen science - engaging the public in research - provides a solution, particularly when coupled with automated routines. In this talk we will provide a broad overview of citizen science approaches and best practices. We will also highlight in particular recent advances through Zooniverse, the world’s largest platform for online citizen science, engaging more than 1.7 million volunteers in tasks including discovering exoplanets, identifying features on Mars’ surface, transcribing artist’s notebooks, and tracking resistance to antibiotics.

Education and outreach in astronomy often focuses on communicating broad astronomical concepts. But how can educators and outreach practitioners also share current astronomical research results with students and the public, conveying both the process of science and the excitement of new discoveries? AAS Nova and Astrobites are two resources freely available to the astronomy community and the general public, intended to help readers learn about the most recent research published across the field of astronomy. Both supported by the American Astronomical Society, these two daily astrophysical literature blogs provide accessible summaries of recent publications in AAS journals and on the arXiv. As both AAS Nova and Astrobites directly distill original studies, these resources constitute a critical bridge between astronomy researchers and educators, outreach practitioners, and the broader astronomy community. The material on these two websites — which includes a total archive of more than 2,500 research study summaries — is written accessibly while still providing access to the original sources and outcomes. As a result, AAS Nova and Astrobites can be used by educators and outreach practitioners to easily introduce the latest in astronomical research studies into classrooms and outreach events.

As the IAU heads towards its second century, many changes have simultaneously transformed Astronomy and the human condition world-wide. Amid the amazing recent discoveries of exoplanets, primeval galaxies, and gravitational radiation, the human condition on Earth has become blazingly interconnected, yet beset with ever-increasing problems of over-population, pollution, and never-ending wars. Fossil-fueled global climate change has begun to yield perilous consequences. And the displacement of people from war-torn nations has reached levels not seen since World War II.

Since 2003, the Communicating Astronomy with the Public (CAP) Conference has facilitated the exchange of ideas and best practices among professionals in the field. This paper reports on the latest edition, CAP 2018, organised in Fukuoka, Japan. It presents a few quantitative outcomes of the conference, the programme and a selection of ideas that were presented and discussed during the meeting. For further details, please consult the Book of Proceedings Communication Astronomy with the Public Conference 2018 2nd Edition, available at: https://www.communicatingastronomy.org/cap2018/

Informal science educators at museums and planetariums face the challenging task of engaging a diverse public audience in contemporary science. To do this they need a solid background in the science itself, educational pedagogy, and modern practices in science communication. The task has gotten even more challenging in the era of big data. Interpreting and visualizing these datasets in planetarium shows and museum exhibits requires specialized technical skills. Furthermore, the increasing pace of discovery means that informal science educators have less time to accomplish these tasks. This presentation will summarize a variety of museum and planetarium community efforts to address these challenges through worldwide collaboration and coordination among museums and planetariums. Solutions include content sharing and distribution mechanisms as well as networking museums and planetariums together to create global worldwide events.

Section 3 of the FM14 focus on the The IAU National Outreach Contacts (NOC) Network. This paper also contains supplementary materials that point to poster presentations that can be found online.