A survey for variable young stars with small telescopes: VIII — Properties of 1687 Gaia selected members in 21 nearby clusters

The Hunting Outbursting Young Stars (HOYS) project performs long-term, optical, multi- filter, high cadence monitoring of 25 nearby young clusters and star forming regions. Utilising Gaia DR3 data we have identified about 17000 potential young stellar members in 45 coherent astrometric groups in these fields. Twenty one of them are clear young groups or clusters of stars within one kiloparsec and they contain 9143 Gaia selected potential members. The cluster distances, proper motions and membership numbers are determined. We analyse long term ( 7 yr) V, R, and I-band light curves from HOYS for 1687 of the potential cluster members. One quarter of the stars are variable in all three optical filters, and two thirds of these have light curves that are symmetric around the mean. Light curves affected by obscuration from circumstellar materials are more common than those affected by accretion bursts, by a factor of 2 – 4. The variability fraction in the clusters ranges from 10 to almost 100 percent, and correlates positively with the fraction of stars with detectable inner disks, indicating that a lot of variability is driven by the disk. About one in six variables shows detectable periodicity, mostly caused by magnetic spots. Two thirds of the periodic variables with disk excess emission are slow rotators, and amongst the stars without disk excess two thirds are fast rotators – in agreement with rotation being slowed down by the presence of a disk

A survey for variable young stars with small telescopes – VIII. Properties of 1687 Gaia selected members in 21 nearby clusters

The Hunting Outbursting Young Stars (HOYS) project performs long-term, optical, multi-filter, high cadence monitoring of 25 nearby young clusters and star forming regions. Utilising Gaia DR3 data we have identified about 17000 potential young stellar members in 45 coherent astrometric groups in these fields. Twenty one of them are clear young groups or clusters of stars within one kiloparsec and they contain 9143 Gaia selected potential members. The cluster distances, proper motions and membership numbers are determined. We analyse long term (≈ 7 yr) V, R, and I-band light curves from HOYS for 1687 of the potential cluster members. One quarter of the stars are variable in all three optical filters, and two thirds of these have light curves that are symmetric around the mean. Light curves affected by obscuration from circumstellar materials are more common than those affected by accretion bursts, by a factor of 2 – 4. The variability fraction in the clusters ranges from 10 to almost 100 percent, and correlates positively with the fraction of stars with detectable inner disks, indicating that a lot of variability is driven by the disk. About one in six variables shows detectable periodicity, mostly caused by magnetic spots. Two thirds of the periodic variables with disk excess emission are slow rotators, and amongst the stars without disk excess two thirds are fast rotators – in agreement with rotation being slowed down by the presence of a disk

A survey for variable young stars with small telescopes: IX - Evolution of spot properties on YSOs in IC 5070

We present spot properties on 32 periodic young stellar objects in IC 5070. Long term, ∼5 yr, light curves in the V, R, and I-bands are obtained through the HOYS (Hunting Outbursting Young Stars) citizen science project. These are dissected into six months long slices, with 3 months oversampling, to measure 234 sets of amplitudes in all filters. We fit 180 of these with reliable spot solutions. Two thirds of spot solutions are cold spots, the lowest is 2150 K below the stellar temperature. One third are warm spots that are above the stellar temperature by less than ∼2000 K. Cold and warm spots have maximum surface coverage values of 40 per cent, although only 16 per cent of warm spots are above 20 per cent surface coverage as opposed to 60 per cent of the cold spots. Warm spots are most likely caused by a combination of plages and low density accretion columns, most common on objects without inner disc excess emission in K − W2. Five small hot spot solutions have <3 percent coverage and are 3000 – 5000 K above the stellar temperature. These are attributed to accretion, and four of them occur on the same object. The majority of our objects are likely to be accreting. However, we observe very few accretion hot spots as either the accretion is not stable on our timescale or the photometry is dominated by other features. We do not identify cyclical spot behaviour on the targets. We additionally identify and discuss a number of objects that have interesting amplitudes, phase changes, or spot properties

Power of Invention : Drawings from Seven Decades by Tony Urquhart

For this catalogue from an exhibition of his drawings, Urquhart comments on specific pieces in the show, their genesis, and the long-standing influence of the Old Masters (particularly Ingres). Reviewing the drawings on view, Heath concludes that Urquhart mastered his technique early, but continues to invent new ways of expressing exterior/interior worlds. List of works. Bio-bibliography 3 p. 3 bibl. ref

Tony Urquhart ; Twenty-five years : Retrospective

Defining himself as a landscape artist, Urquhart outlines his life and the development of his ideas through descriptions of his paintings, boxes, drawings, and wall and floor works. Biographical notes. 40 bibl. ref

Basia Irland : Accretions

Discussing Irland's wrapped and bindled constructions, the authors focus on her ritualistic use of materials and processes and her literary and mythic references. Poem by Whitlock. Biographical notes. 7 bibl. ref

The Work of Art : Six Artists

Broun offers a history of sketching and drawing in Europe for an exhibit of studies and final works by six Canadian artists. Statements by the artists. Biographical notes. 7 bibl. ref

Feasibility Study for a Survey of Fishers

The promotion and development of a thriving fishing industry - that sustains livelihoods whilst sustainably exploiting marine resources - requires the development of social objectives in fisheries policy alongside environmental and economic objectives. In turn, these social objectives must be informed by a strong social science evidence base. Existing evidence is largely economic, with a focus on employment and a number of socio-demographic variables collected to comply with requirements under the EU Data Collection Framework (DCF). While this data has proved a useful starting point, there are significant gaps in understanding of the broader social issues affecting fishing communities. Data that includes socio-psychological measures of fishers, such as attitudes, knowledge, perceptions, values, and motivations driving behaviour, would be a valuable asset for both policy makers and industry stakeholders. Through a combination of desk based reviews and stakeholder consultation via interviews and workshops, the project aimed to understand the extent to which a new social survey of fishers could add value to the existing evidence base and begin to identify areas of consensus on social data needs. Discussions, recognising that fishers are a hard to reach group, explored alternative approaches for implementing a survey, in terms of sampling and data collection strategies. As the project progressed, it became clear that any new social survey is likely to be more successful if designed and deployed collaboratively between government, researchers and fishing stakeholders. Indeed, stakeholders indicated that a survey that is jointly designed, funded and delivered, would achieve better response rates and support from fishers. The project team therefore sought to develop a framework for a co-produced survey that would actively involve a variety of stakeholders from policy makers through to fishers themselves