Upload metadata to DOAJ

This is a guide to show journal editors how they can register/upload metadata about their journal's published papers to DOAJ (Directory of Open Access Journals) directly through the system behind tidsskrift.dk, OJS. This is a possibility for journals indexed in DOAJ. Should you wish to read more about DOAJ, you can visit our page on the subject. Here you will also find a contact formular if you wish to learn more or get help indexing your journal in DOAJ.Denne vejledning forklarer, hvordan et tidsskrift kan få uploadet/registreret metadata om publicerede artikler ved DOAJ (Directory of Open Access Journals) gennem systemet bag tidsskrift.dk, OJS. Dette er en mulighed for tidsskrifter, der er indekseret hos DOAJ. Ønsker du at læse mere om DOAJ, kan du besøge vores side om emnet. Her finder du også en kontaktformular, hvis du ønsker at høre mere eller få hjælp til at få dit tidsskrift indekseret hos DOAJ

The lost sunspot cycle: New support from Be10 measurements

It has been suggested that the deficit in the number of spots on the surface of the Sun between 1790 and 1830, known as the Dalton minimum, contained an extra cycle that was not identified in the original sunspot record by Wolf. Though this cycle would be shorter and weaker than the average solar cycle, it would shift the magnetic parity of the solar magnetic field of the earlier cycles. This extra cycle is sometimes referred to as the 'lost solar cycle' or 'cycle 4b'. Here we reanalyse Be10 measurements with annual resolution from the NGRIP ice core in Greenland in order to investigate if the hypothesis regarding a lost sunspot cycle is supported by these measurements. Specifically, we make use of the fact that the Galactic cosmic rays, responsible for forming Be10 in the Earth's atmosphere, are affected differently by the open solar magnetic field during even and odd solar cycles. This fact enables us to evaluate if the numbering of cycles earlier than cycle 5 is correct. For the evaluation, we use Bayesian analysis, which reveals that the lost sunspot cycle hypothesis is likely to be correct. We also discuss if this cycle 4b is a real cycle, or a phase catastrophe, and what implications this has for our understanding of stellar activity cycles in general.Comment: accepted for publication in A&

Beretning om Tidsskrift.dk og ebooks.au.dk i 2021

In 2021, the work in connection with the Royal Library's publishing service was characterized by an upgrade of the Open Journal Systems (OJS) server and the Open Monograph Press (OMP) server as well as the ongoing operation of the two servers. A new contract was prepared for journals to be published on tidsskrift.dk. The service became free, while the requirements for magazines that can be recorded on the server were tightened. At the same time, the Royal Library in collaboration with Aalborg University Library, CBS library and Directory of Open Access Journals (DOAJ) a project to get more Danish Open Access (OA) journals in DOAJ.IndstillingerAlexandra Fogtmann-Schulz: http://orcid.org/0000-0003-0660-5345 IndstillingerJesper Boserup Thestrup: http://orcid.org/0000-0002-7974-674XRie Karen Marie Iversen: http://orcid.org/0000-0003-1069-5689 I 2021 fortsatte væksten af begge vores publiceringsservices. Således blev der udgivet 29 nye e-bøger, og 9 nye tidsskrifter udgav deres første nummer. Der blev udgivet godt 4.000 nye artikler, og det samlede antal downloads og visninger på tidsskrift.dk nåede op på 7,8 mio. Aktiviteterne i forbindelse med Det Kgl. Biblioteks publiceringsservice var præget af en opgradering af Open Journal Systems (OJS) serveren og Open Monograph Press (OMP) serveren samt den løbende drift af de to servere. Der blev udarbejdet en ny kontrakt til tidsskrifter, der skal udgive på tidsskrift.dk. Tjenesten blev gratis, samtidigt med at kravene til tidsskrifter, der kan optages på serveren, blev skærpede. Samtidigt startede Det Kgl. Bibliotek i samarbejde med Aalborg Universitetsbibliotek, CBS bibliotek og Directory of Open Access Journals (DOAJ) et projekt for at få optaget flere danskeOpen Access (OA) tidsskrifter i DOAJ

Danske OA-tidsskrifter og Directory of Open Access Journals (DOAJ)

The report describes a project to get more Danish journals included in DOAJ. The project was initiated in autumn 2020 and started in January 2021. The background has been to strengthen communication, collaboration and knowledge sharing across university libraries within the Royal Danish Library, but also to collaborate nationally with other university libraries that work with OJS servers (Aalborg University Library and Copenhagen Business School). The initiative has been initiated to increase the quality and visibility of the Royal Danish Library Open Science services as well as strengthening the OA journals in terms of visibility and traffic.Rapporten beskriver et projekt, der skulle få flere danske tidsskrifter optaget i DOAJ. Projektet blev initieret i efteråret 2020 og påbegyndt januar 2021. Baggrunden har været at styrke kommunikation, samarbejde og videndeling på tværs af universitetsbiblioteker inden for Det Kgl. Bibliotek, men også at samarbejde nationalt med andre universitetsbiblioteker, der arbejder med OJS servere (Aalborg Universitetsbibliotek og Copenhagen Business School). Initiativet er igangsat for at øge kvalitet og synlighed af Det Kgl. Biblioteks Open Science services samt styrke OA-tidsskrifterne i forhold til synlighed og trafik. 

The Kepler-10 planetary system revisited by HARPS-N: A hot rocky world and a solid Neptune-mass planet

Kepler-10b was the first rocky planet detected by the Kepler satellite and con- firmed with radial velocity follow-up observations from Keck-HIRES. The mass of the planet was measured with a precision of around 30%, which was insufficient to constrain models of its internal structure and composition in detail. In addition to Kepler-10b, a second planet transiting the same star with a period of 45 days was sta- tistically validated, but the radial velocities were only good enough to set an upper limit of 20 Mearth for the mass of Kepler-10c. To improve the precision on the mass for planet b, the HARPS-N Collaboration decided to observe Kepler-10 intensively with the HARPS-N spectrograph on the Telescopio Nazionale Galileo on La Palma. In to- tal, 148 high-quality radial-velocity measurements were obtained over two observing seasons. These new data allow us to improve the precision of the mass determina- tion for Kepler-10b to 15%. With a mass of 3.33 +/- 0.49 Mearth and an updated radius of 1.47 +0.03 -0.02 Rearth, Kepler-10b has a density of 5.8 +/- 0.8 g cm-3, very close to the value -0.02 predicted by models with the same internal structure and composition as the Earth. We were also able to determine a mass for the 45-day period planet Kepler-10c, with an even better precision of 11%. With a mass of 17.2 +/- 1.9 Mearth and radius of 2.35 +0.09 -0.04 Rearth, -0.04 Kepler-10c has a density of 7.1 +/- 1.0 g cm-3. Kepler-10c appears to be the first strong evidence of a class of more massive solid planets with longer orbital periods.Comment: 44 pages, 8 figures, accepted for publication in Ap

Observational evidence for enhanced magnetic activity of superflare stars

Superflares are large explosive events on stellar surfaces one to six orders-of-magnitude larger than the largest flares observed on the Sun throughout the space age. Due to the huge amount of energy released in these superflares, it has been speculated if the underlying mechanism is the same as for solar flares, which are caused by magnetic reconnection in the solar corona. Here, we analyse observations made with the LAMOST telescope of 5,648 solar-like stars, including 48 superflare stars. These observations show that superflare stars are generally characterized by larger chromospheric emissions than other stars, including the Sun. However, superflare stars with activity levels lower than, or comparable to, the Sun do exist, suggesting that solar flares and superflares most likely share the same origin. The very large ensemble of solar-like stars included in this study enables detailed and robust estimates of the relation between chromospheric activity and the occurrence of superflares

Ages for exoplanet host stars

Age is an important characteristic of a planetary system, but also one that is difficult to determine. Assuming that the host star and the planets are formed at the same time, the challenge is to determine the stellar age. Asteroseismology provides precise age determination, but in many cases the required detailed pulsation observations are not available. Here we concentrate on other techniques, which may have broader applicability but also serious limitations. Further development of this area requires improvements in our understanding of the evolution of stars and their age-dependent characteristics, combined with observations that allow reliable calibration of the various techniques.Comment: To appear in "Handbook of Exoplanets", eds. Deeg, H.J. & Belmonte, J.A, Springer (2018

An Ultra-short Period Rocky Super-Earth with a Secondary Eclipse and a Neptune-like Companion around K2-141

Ultra-short period (USP) planets are a class of low mass planets with periods shorter than one day. Their origin is still unknown, with photo-evaporation of mini-Neptunes and in-situ formation being the most credited hypotheses. Formation scenarios differ radically in the predicted composition of USP planets, it is therefore extremely important to increase the still limited sample of USP planets with precise and accurate mass and density measurements. We report here the characterization of an USP planet with a period of 0.28 days around K2-141 (EPIC 246393474), and the validation of an outer planet with a period of 7.7 days in a grazing transit configuration. We derived the radii of the planets from the K2 light curve and used high-precision radial velocities gathered with the HARPS-N spectrograph for mass measurements. For K2-141b we thus inferred a radius of $1.51\pm0.05~R_\oplus$ and a mass of $5.08\pm0.41~M_\oplus$, consistent with a rocky composition and lack of a thick atmosphere. K2-141c is likely a Neptune-like planet, although due to the grazing transits and the non-detection in the RV dataset, we were not able to put a strong constraint on its density. We also report the detection of secondary eclipses and phase curve variations for K2-141b. The phase variation can be modeled either by a planet with a geometric albedo of $0.30 \pm 0.06$ in the Kepler bandpass, or by thermal emission from the surface of the planet at $\sim$3000K. Only follow-up observations at longer wavelengths will allow us to distinguish between these two scenarios.Comment: 16 pages, 10 figures., accepted for publication in A

The Kepler-10 Planetary System Revisited by HARPS-N: A Hot Rocky World and a Solid Neptune-Mass Planet

Kepler-10b was the first rocky planet detected by the Kepler satellite and con- firmed with radial velocity follow-up observations from Keck-HIRES. The mass of the planet was measured with a precision of around 30%, which was insufficient to constrain models of its internal structure and composition in detail. In addition to Kepler-10b, a second planet transiting the same star with a period of 45 days was sta- tistically validated, but the radial velocities were only good enough to set an upper limit of 20 Mearth for the mass of Kepler-10c. To improve the precision on the mass for planet b, the HARPS-N Collaboration decided to observe Kepler-10 intensively with the HARPS-N spectrograph on the Telescopio Nazionale Galileo on La Palma. In to- tal, 148 high-quality radial-velocity measurements were obtained over two observing seasons. These new data allow us to improve the precision of the mass determina- tion for Kepler-10b to 15%. With a mass of 3.33 +/- 0.49 Mearth and an updated radius of 1.47 +0.03 -0.02 Rearth, Kepler-10b has a density of 5.8 +/- 0.8 g cm-3, very close to the value -0.02 predicted by models with the same internal structure and composition as the Earth. We were also able to determine a mass for the 45-day period planet Kepler-10c, with an even better precision of 11%. With a mass of 17.2 +/- 1.9 Mearth and radius of 2.35 +0.09 -0.04 Rearth, -0.04 Kepler-10c has a density of 7.1 +/- 1.0 g cm-3. Kepler-10c appears to be the first strong evidence of a class of more massive solid planets with longer orbital periods.Comment: 44 pages, 8 figures, accepted for publication in Ap