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/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Using the Secular Light Curve (SLC) formalism (Ferr\'in, 2010a, PSS, 58,365-391), we searched for cometary activity of six NEAS: 2201 Oljato. The SLCexhibits significant cometary activity and evidence of an eclipse. 3200Phaethon. Is the parent of the Geminid meteor stream and exhibited a faint tailat perihelion in several oppositions. The SLC fails to show cometary activityusing a 1995 to 2017 data set, suggesting that we are in the presence of adormant cometary nucleus. 99942 Apophis. This SLC does not shows evidence ofcometary activity, however it shows evidence of an eclipse. The evidence of adouble nature is confirmed with Goldstone and Arecibo radar observations.162173 Ryugu. This NEA is the target of the Hayabusa 2 spacecraft mission. TheSLC exhibits an enhancement consistent with cometary activity. It may bepossible to confirm or deny this activity by the end of the mission. 495848=2002 QD7. This NEA shows deviations from a flat distribution near perihelion in2007 and 2017. However our own observations in 2018 show a bare nucleus, fromwhich we obtain an absolute nuclear magnitude mV(nucleus) = 18.32+-0.03 (usingpV=0.04). The equivalent diameter is D=1.43+-0.10 km. 6063 Jason. The SLC ofthis NEA exhibits low level cometary activity centred at perihelion. The factthat a cursory search for low level active comets among NEAs has uncovered fourpositive objects out of 6, hints that many more faint comets should exist asyet undetected.

Secular Light Curves of NEAs 2201 Oljato, 3200 Phaethon, 99942 Apophis, 162173 Ryugu, 495848, and 6063 Jason