{"title":"CCD photometric studies of two Primitive C-type main-belt asteroids: (51) Nemausa and (52) Europa","authors":"Shuang Wang, Yuangui Yang, Huiyu Yuan, Ligang Yu","doi":"10.1016/j.newast.2025.102391","DOIUrl":null,"url":null,"abstract":"<div><div>We present new CCD photometry for primitive C-type main-belt asteroids (51) Nemausa and (52) Europa performed on several nights of 2016, by using the 60-cm telescope at Xinglong station of NAOC. From our new data, the rotation periods are determined as 7.784840 h for (51) Nemausa and 5.629960 h for (52) Europa. Based on the convex inversion method, the pole ambiguity was removed, and we refined pole directions and triaxial ratios as follows, (168 °, <span><math><mrow><mo>−</mo><mn>6</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span>) with <span><math><mrow><mi>a</mi><mo>/</mo><mi>b</mi><mo>=</mo><mn>1</mn><mo>.</mo><mn>09</mn></mrow></math></span> and <span><math><mrow><mi>b</mi><mo>/</mo><mi>c</mi><mo>=</mo><mn>1</mn><mo>.</mo><mn>03</mn></mrow></math></span> for (51) Nemausa, and a pole is derived as (256°, 32°) with <span><math><mrow><mi>a</mi><mo>/</mo><mi>b</mi><mo>=</mo><mn>1</mn><mo>.</mo><mn>04</mn></mrow></math></span> and <span><math><mrow><mi>b</mi><mo>/</mo><mi>c</mi><mo>=</mo><mn>1</mn><mo>.</mo><mn>33</mn></mrow></math></span> for (52) Europa. From the parameters of 49 asteroids, a statistic study was carried out. All these results will help us to understand the physical properties of pristine small objects in the solar system.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"119 ","pages":"Article 102391"},"PeriodicalIF":1.9000,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"New Astronomy","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1384107625000405","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
We present new CCD photometry for primitive C-type main-belt asteroids (51) Nemausa and (52) Europa performed on several nights of 2016, by using the 60-cm telescope at Xinglong station of NAOC. From our new data, the rotation periods are determined as 7.784840 h for (51) Nemausa and 5.629960 h for (52) Europa. Based on the convex inversion method, the pole ambiguity was removed, and we refined pole directions and triaxial ratios as follows, (168 °, ) with and for (51) Nemausa, and a pole is derived as (256°, 32°) with and for (52) Europa. From the parameters of 49 asteroids, a statistic study was carried out. All these results will help us to understand the physical properties of pristine small objects in the solar system.
期刊介绍:
New Astronomy publishes articles in all fields of astronomy and astrophysics, with a particular focus on computational astronomy: mathematical and astronomy techniques and methodology, simulations, modelling and numerical results and computational techniques in instrumentation.
New Astronomy includes full length research articles and review articles. The journal covers solar, stellar, galactic and extragalactic astronomy and astrophysics. It reports on original research in all wavelength bands, ranging from radio to gamma-ray.