Related papers: Rotational Mass Shedding from Asteroid (6478) Gaul…
We describe active asteroid 331P/Gibbs (2012 F5) using archival Hubble Space Telescope data taken between 2015 and 2018. 331P is an outer main-belt active asteroid with a long-lived debris trail that formed in 2011. Embedded in the debris…
Context: Various ideas have been proposed to explain the formation of the Geminid meteoroid stream from the asteroid (3200) Phaethon. However, little has been studied about the Geminid formation based on the assumption that mass ejection…
We examine the development of the active asteroid 311P/PANSTARRS (formerly, 2013 P5) in the period from 2013 September to 2014 February using high resolution images from the Hubble Space Telescope. This multi-tailed object is characterized…
The dust emission from active asteroids is likely driven by collisions, fast rotation, sublimation of embedded ice, and combinations of these. Characterising these processes leads to a better understanding of their respective influence on…
Observations with the adaptive optics system on the Very Large Telescope reveal that outer main belt asteroid (702) Alauda has a small satellite with primary to secondary diameter ratio of $\sim$56. The secondary revolves around the primary…
We report new observations of the active asteroid P/2010 A2 taken when it made its closest approach to the Earth (1.06 au in 2017 January) after its first discovery in 2010. Despite a crucial role of the rotational period in clarifying its…
Surface shedding of an asteroid is a failure mode where surface materials fly off due to strong centrifugal forces beyond the critical spin period, while the internal structure does not deform significantly. This paper proposes a possible…
The asteroid (3200) Phaethon is known to be the parent body of the Geminids, although meteor showers are commonly associated with the activity of periodic comets. What is most peculiar to the asteroid is its comet-like activity in the…
We present deep imaging observations of activated asteroid P/2016 G1 (PANSTARRS) using the 10.4m Gran Telescopio Canarias (GTC) from late April to early June 2016. The images are best interpreted as the result of a relatively short-duration…
We present observations carried out using the 10.4 m Gran Telescopio Canarias and an interpretative model of the dust environment of activated asteroid 313P/Gibbs. We discuss three different models relating to different values of the dust…
Exploration of asteroid (101955) Bennu by the OSIRIS-REx mission has provided an in-depth look at this rubble-pile near-Earth asteroid. In particular, the measured gravity field and the detailed shape model of Bennu indicate significant…
We have performed detailed dynamical modeling of the structure of a faint dust band observed in coadded IRAS data at an ecliptic latitude of 17$^{\circ}$ that convincingly demonstrates that it is the result of a relatively recent…
In this work we characterize the recently discovered active main belt object P/2012 F5 (Gibbs), which was discovered with a dust trail > 7' in length in the outer main belt, 7 months prior to aphelion. We use optical imaging obtained on UT…
Most asteroids with a diameter larger than $\sim 300 \ {\rm m}$ are rubble piles i.e. consisting of more than one solid object. All asteroids are rotating but almost all asteroids larger than $\sim 300 \ {\rm m}$ rotate with a period longer…
We examine the spectral properties of asteroid pairs that were disrupted in the last 2 Myrs to examine whether the site of the fission can be revealed. We studied the possibility that the sub-surface material, perhaps on one hemisphere, has…
The rubble pile spin barrier is an upper limit on the rotation rate of asteroids larger than ~200-300 m. Among thousands of asteroids with diameters larger than ~300 m, only a handful of asteroids are known to rotate faster than 2.0 h, all…
We report on observations of near-Earth asteroid 2011 MD with the Spitzer Space Telescope. We have spent 19.9 h of observing time with channel 2 (4.5 {\mu}m) of the Infrared Array Camera and detected the target within the 2{\sigma}…
We present a dynamical analysis of the fragmented active asteroid 331P/Gibbs. Using archival images taken by the Hubble Space Telescope from 2015 to 2018, we measured the astrometry of the primary and the three brightest (presumably the…
The active asteroid 311P is one of the two targets of a planned Chinese asteroid exploration mission Tianwen-2. During 2013, 311P experienced several mass-loss events and exhibited multiple comet-like tails. Here we analyze the morphology…
I report the discovery of a new effect of General Relativity which is important to understand very rapidly rotating (Kerr) black holes. The orbital velocity of a test particle is no longer a monotonic function of the orbit radius when the…