English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Open

Presents the pdf analysis as premium feature

PDF Analysis

Insights

Presents the summarisation as premium feature

Summarisation

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Themis is an old and statistically robust asteroid family populating theouter main belt, and resulting from a catastrophic collision that took place2.5$\pm$1.0 Gyr ago. Within the old Themis family a young sub-family, Beagle,formed less than 10 Myr ago, has been identified. We present the results of aspectroscopic survey in the visible and near infrared range of 22 Themis and 8Beagle families members. The Themis members investigated exhibit a wide rangeof spectral behaviors, while the younger Beagle family members look spectrallybluer with a smaller spectral slope variability. The best meteorite spectralanalogues found for both Themis and Beagle families members are carbonaceouschondrites having experienced different degrees of aqueous alteration,prevalently CM2 but also CV3 and CI, and some of them are chondrite samplesbeing unusual or heated. We extended the spectral analysis including the dataavailable in the literature on Themis and Beagle families members, and welooked for correlations between spectral behavior and physical parameters usingthe albedo and size values derived from the WISE data. The analysis of thislarger sample confirm the spectral diversity within the Themis family and thatBeagle members tend to be bluer and to have an higher albedo. The differencesbetween the two family may be partially explained by space weatheringprocesses, which act on these primitive surfaces in a similar way than onS-type asteroids, i.e. producing reddening and darkening. However we seeseveral Themis members having albedos and spectral slopes similar to the youngBeagle members. Alternative scenarios are proposed including heterogeneity inthe parent body having a compositional gradient with depth, and/or the survivalof projectile fragments having a different composition than the parent body.

Spectral variability on primitive asteroids of the Themis and Beagle families: space weathering effects or parent body heterogeneity?