Helen Usher

ORCID: 0000-0002-8658-5534
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About
Contact & Profiles
Research Areas
  • Astro and Planetary Science
  • Isotope Analysis in Ecology
  • Classical Antiquity Studies
  • Space Exploration and Technology
  • Atmospheric Ozone and Climate
  • Planetary Science and Exploration
  • Gamma-ray bursts and supernovae
  • Stellar, planetary, and galactic studies
  • Astronomy and Astrophysical Research
  • Mass Spectrometry Techniques and Applications
  • Scientific Computing and Data Management
  • Hong Kong and Taiwan Politics
  • Education and Islamic Studies
  • Science Education and Pedagogy
  • Space Satellite Systems and Control
  • Archaeology and Historical Studies
  • Opportunistic and Delay-Tolerant Networks
  • Linguistics and language evolution
  • Classical Studies and Philology
  • Species Distribution and Climate Change
  • Lexicography and Language Studies
  • Conferences and Exhibitions Management
  • Astrophysics and Star Formation Studies
  • Biblical Studies and Interpretation
  • Ancient Near East History

The Open University
2020-2024

Hong Kong Metropolitan University
2023

Campbell Collaboration
2022

Canada–France–Hawaii Telescope
2020-2022

University College London
1982-1983

Abstract The impact of the Double Asteroid Redirection Test spacecraft into Dimorphos, moon asteroid Didymos, changed Dimorphos’s orbit substantially, largely from ejection material. We present results 12 Earth-based facilities involved in a world-wide campaign to monitor brightness and morphology ejecta first 35 days after impact. After an initial brightening ∼1.4 mag, we find consistent dimming rates 0.11–0.12 mag day −1 week, 0.08–0.09 over entire study period. system returned its...

10.3847/2041-8213/ad0fdd article EN cc-by The Astrophysical Journal Letters 2023-12-01

Abstract The world’s first planetary defense test mission was carried out in late 2022 by NASA’s Double Asteroid Redirection Test (DART) mission. main DART spacecraft, which accompanied the ASI-provided LICIACube cubesat, intentionally impacted Dimorphos, smaller secondary of near-Earth object binary system (65803) Didymos, on September 26. impact released a large amount ejecta, which, combined with spacecraft’s momentum, produced observed 33 ± 1 minute period change that subsequently from...

10.3847/psj/ad4345 article EN cc-by The Planetary Science Journal 2024-05-01

We report results from new and archival observations of the newly discovered active asteroid (248370) 2005 QN_137, which has been determined to be a likely main-belt comet based on subsequent discovery that it is recurrently near perihelion. From data analysis, we estimate g'-, r'-, i'-, z'-band absolute magnitudes for nucleus H_g=16.62+/-0.13, H_r=16.12+/-0.10, H_i=16.05+/-0.11, H_z=15.93+/-0.08, corresponding colors g'-r'=0.50+/-0.16, r'-i'=0.07+/-0.15, i'-z'=0.12+/-0.14, an equivalent...

10.3847/2041-8213/ac2c62 article EN The Astrophysical Journal Letters 2021-11-01

Abstract The LCO Outbursting Objects Key (LOOK) Project uses the telescopes of Las Cumbres Observatory (LCO) Network to (1) systematically monitor a sample previously discovered over whole sky, assess evolutionary state these distant remnants from early solar system, and (2) use alerts existing sky surveys rapidly respond characterize detected outburst activity in all small bodies. data gathered on outbursts helps each outburst’s evolution with time, frequency magnitude distribution general,...

10.3847/psj/ac7a31 article EN cc-by The Planetary Science Journal 2022-07-01

Cometary activity may be driven by ices with very low sublimation temperatures, such as carbon monoxide ice, which can sublimate at distances well beyond 20 au. This point is emphasized the discovery of Oort cloud comet C/2014 UN$_{271}$ (Bernardinelli-Bernstein), and its observed out to $\sim$26 Through observations this comet's optical brightness behavior, we potentially discern drivers in outer solar system. We present a study Bernardinelli-Bernstein broad-band photometry taken 19-20 au...

10.3847/2041-8213/ac7bec article EN cc-by The Astrophysical Journal Letters 2022-07-01

The impact of the DART spacecraft into Dimorphos, moon asteroid Didymos, changed Dimorphos' orbit substantially, largely from ejection material. We present results twelve Earth-based facilities involved in a world-wide campaign to monitor brightness and morphology ejecta first 35 days after impact. After an initial brightening ~1.4 magnitudes, we find consistent dimming rates 0.11-0.12 magnitudes/day week, 0.08-0.09 over entire study period. system returned its pre-impact 24.3-25.3 through...

10.48550/arxiv.2310.12089 preprint EN other-oa arXiv (Cornell University) 2023-01-01

Abstract We present multi-filter observations of Centaur-like Jupiter-family comet 2023 RN 3 conducted as part the Las Cumbres Observatory Outbursting Objects Key Project, well analysis archival data in which was expected to be present. find clear evidence comet-like mass loss form an extended morphology on UT November 16 and 18, increase intrinsic brightness &gt;4 mag between 2022 September November. also report broadband colors for coma <?CDATA $g^{\prime} -r^{\prime} =0.61\pm 0.03$?>...

10.3847/2515-5172/ad12ce article EN cc-by Research Notes of the AAS 2023-12-08

An abstract is not available for this content so a preview has been provided. Please use the Get access link above information on how to content.

10.1017/s0009840x00115069 article EN The Classical Review 1982-10-01

Abstract Amateur astronomers can make useful contributions to the study of comets. They add temporal coverage and multiscale observations that aid fast-changing large-scale comet features. We document review amateur observing campaign set up complement Rosetta space mission, including data submitted date, consider campaign’s effectiveness in light experience from previous campaigns. report results surveys participants, astronomy community, schools who participated a 46P campaign. draw...

10.3847/psj/abca46 article EN cc-by The Planetary Science Journal 2020-12-01

&amp;#160;There is a growing body of work on equity, diversity and inclusivity within professional astronomy [1] [2] [3], [4] [5][6][7]. Collaborations between amateur astronomers (pro-am collaborations) are the rise. But literature still sparse. It increasingly important to understand makeup astronomical communities, barriers wider involvement. In this day age, should belong everyone, everyone feel like they belong.&amp;#160;&amp;#160;The demographics societies online including adjacent...

10.5194/epsc2020-1084 article EN 2020-10-08

The (small) Europlanet social media team has agreed aims of: Informing, Enthusing, Engaging, Encouraging and Celebrating the European Planetary Science Community wider community too.&amp;#160; Their work supplements more traditional channels of website, newletters mailing lists.&amp;#160;But how can this be done most effectively?&amp;#160; What should used?&amp;#160; content? frequency?&amp;#160;If needs communities are to met, they first need identified.&amp;#160; There is currently a lack...

10.5194/epsc2020-893 article EN 2020-10-08

The Rosetta Mission invited amateur astronomers to be part of a ground-based observing campaign for Comet 67P/Churyumov&amp;#8211;Gerasimenko.&amp;#160; Amateurs, with greater access telescope time and wider geographical coverage, can add important temporal coverage scale observations complement those professional astronomers. They the bigger picture. This allows multi-scale analysis comet activity.This followed on from campaigns in support Halley-related Deep Impact Missions, as well...

10.5194/epsc2020-849 article EN 2020-10-08

The Pro-Am Collaborative Astronomy (PACA) Project 1.0, evolved from the successful NASA observational campaign CIOC to characterize Oort-cloud comet C/2012 S1(ISON) in 2013 on its initial passage through inner solar system. With no spacecraft en route ISON, many of assets were utilised comet. inclusion amateur astronomers, educators, students, outreach coordinators and astronomy journalists; adaptation various social media platforms components emerging field citizen science, four phases for...

10.5194/epsc2020-1002 article EN 2020-10-08

Amateur astronomers can make useful contributions to the study of comets. They add temporal coverage and multi-scale observations which aid fast-changing, large-scale comet features. We document review amateur observing campaign set up complement Rosetta space mission, including data submitted date, consider campaign's effectiveness in light experience from previous campaigns. report results surveys participants, astronomy community, schools who participated a 46P campaign. draw lessons for...

10.48550/arxiv.2011.07123 preprint EN cc-by arXiv (Cornell University) 2020-01-01

The LCO Outbursting Objects Key (LOOK) Project uses the telescopes of Las Cumbres Observatory (LCO) Network to: (1) to systematically monitor a sample Dynamically New Comets over whole sky, and (2) use alerts from existing sky surveys rapidly respond characterize detected outburst activity in all small bodies. data gathered on outbursts helps each outburst's evolution with time, assess frequency magnitude distribution general, contributes understanding processes volatile Solar System. LOOK...

10.48550/arxiv.2206.09028 preprint EN cc-by arXiv (Cornell University) 2022-01-01

&amp;lt;p&amp;gt;During 2021 we started a project called &amp;lt;strong&amp;gt;Comet Chasers&amp;lt;/strong&amp;gt;, to work with Primary schools in South Wales, bringing astronomy-related activities into the classroom teach core skills.&amp;lt;/p&amp;gt; period of (on 10 June 2021) there was partial solar eclipse (around 22% area), so around that event were also included.&amp;amp;#160;&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;Obviously, ideal scenario students would be able view full duration...

10.5194/epsc2022-1240 preprint EN 2022-09-23

&amp;lt;p&amp;gt;Comet observation and analysis is an area where amateur observers can make a significant contribution.&amp;amp;#160; Their observations allow regular monitoring of comets, alerting the professional community to interesting events, providing raw data supplement data.&amp;amp;#160; The links between communities are therefore very important. &amp;amp;#160;&amp;lt;/p&amp;gt; challenging.&amp;amp;#160; Encouraging agree consistent methodologies, parameters for analysis, will...

10.5194/epsc2022-1135 preprint EN 2022-09-23

&amp;lt;p&amp;gt;CC is now expanding to provide resources meet the needs of CfW and Welsh language. was first implemented in September 2021, shifting educational focus from content-based learning skills-based learning, giving teachers more freedom regarding contents their lessons. This brings novel complications, like difficulty preparing stimulating lessons while also including required skills. CC aims solve these problems by supplying with a variety easy-to-follow lesson plans,...

10.5194/epsc2022-1172 preprint EN 2022-09-23

The J. A. C. T. Greek Course (II) - Joint Association of Classical Teachers: A World Heroes. Selections from Homer, Herodotus and Sophocles. (The JACT Course.) Pp. ix + 139; 38 illustrations, 5 maps. Cambridge University Press, 1979. Limp, £4·50. Volume 30 Issue 2

10.1017/s0009840x00235452 article EN The Classical Review 1980-10-01

Reading Greek - Greek: the Joint Association of Classical Teachers' Course. Vol. i Text, vol. ii Grammar, Vocabulary and Exercises. Pp. xvi + 182, x 366. Cambridge University Press, 1978. Paper. Volume 30 Issue 1

10.1017/s0009840x00234252 article EN The Classical Review 1980-04-01

An abstract is not available for this content so a preview has been provided. Please use the Get access link above information on how to content.

10.1017/s0009840x00229090 article EN The Classical Review 1978-10-01

An abstract is not available for this content so a preview has been provided. Please use the Get access link above information on how to content.

10.1017/s0009840x00224414 article EN The Classical Review 1977-10-01
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