Richard Miles

British Astronomical Association | BAA · Asteroids and Remote Planets Section

First published occultation profile of the nucleus of Centaur-comet 29P/Schwassmann-Wachmann

A Cousins R photometric observing campaign [1] monitoring Comet 29P/S-W1 from 2014 to 2022 has identified more than 160 outbursts (median timing accuracy, 0.18 days); this apparent outburst rate is almost three times greater than previously recognised. Outbursts exhibited a bi-modal distribution in terms of their relative intensity and seasonal dep...

We report results from new and archival observations of the newly discovered active asteroid (248370) 2005 QN 173 (also now designated Comet 433P), which has been determined to be a likely main-belt comet based on a subsequent discovery that it is recurrently active near perihelion. From archival data analysis, we estimate g ′ -, r ′ -, i ′ -, and...

Aims. Very small asteroids (VSAs, objects with diameters smaller than about 150 m) can be spun up by the YORP effect to rotation periods as short as tens of seconds. This effect has been observed for many of them. It is also hypothesised, that in the same process their spin axes are asymptotically drawn to the position perpendicular to the orbital...

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 a subsequent discovery that it is recurrently active near perihelion. From archival data analysis, we estimate g'-, r'-, i'-, and z'-band absolute magnitudes for the nuc...

On 4 March 2021 at 9 UTC a 30-m in diameter near-Earth asteroid 2021 DW1 passed the Earth at a distance of 570000 km, reaching the maximum brightness of V=14.6 mag. We observed it photometrically from 2 March, when it was visible at V=16.5 mag, until 7 March (V=18.2 mag). During that time 2021 DW1 swept a 170 degrees long arc in the northern sky, s...

The stellar occultation method is a particularly powerful tool for probing the nature of distant solar system objects. Here we report a single observation of a close appulse of comet 29P/Schwassmann-Wachmann 1 to a 14 mag star that showed no significant deviation in the recorded light curve on a 2.25 s time resolution (corresponding to 27 km in pro...

The Centaurs are the small solar system bodies intermediate between the active inner solar system Jupiter family comets and their inactive progenitors in the trans-Neptunian region. Among the fraction of Centaurs which show comet-like activity, 174P/Echeclus is best known for its massive 2005 outburst in which a large apparently active fragment was...

The Centaurs are the small solar system bodies intermediate between the active inner solar system Jupiter Family Comets and their inactive progenitors in the trans-Neptunian region. Among the fraction of Centaurs which show comet-like activity, 174P/Echeclus is best known for its massive 2005 outburst in which a large apparently active fragment was...

Energy sources powering long-lived cometary jets and outbursts have yet to be identified. Such phenomena can be seen as de facto manifestations of transient wetted zones beneath a disintegrating surface crust, in which latent heat of vaporisation is extracted from the liquid phase to power the outflow of material. Activity subsides when the wetted...

This poster discusses the various avenues via which amateur astronomers can contribute to scientific advancement in the field of Astronomy. These include: participating in Citizen Science projects; having a presence on academic social networking sites such as ResearchGate, Mendeley, Academia.edu and Google Scholar; and publishing original research...

This observing method article has been posted as a tutorial on the homepage of the British Astronomical Association (https://britastro.org). See also: https://britastro.org/node/18562

We describe a method for deriving Cousins Rc magnitudes from r, B, and V stellar photometry in the UCAC4 catalogue, valid in the range 9 < Rc < 16. The source of the majority of UCAC4 reference star photometry is the AAVSO Photometric All-Sky Survey (APASS) catalogue. Version 433 of the software Astrometrica is updated so that, provided the UCAC4 c...

Multi-chord occultation timings for (130) Elektra. (Report of the Asteroids and Remote Planets Section of the British Astronomical Association)

Results of high-cadence observations of Comet 29P during 2014-2018 are presented and the types of outburst characterised. Between 2014 March 03 and 2018 April 24, a total of 59 outbursts were detected and quantified in terms of outburst date and amplitude. The observed frequency corresponds to an average of >12 outbursts p.a. which is much higher t...

Stellar occultations by comets are generally problematic. The coma is usually too tenuous to be detected by the attenuation effect on stars unless the comet is a very active one and the nucleus passes within a few hundred kilometers of the star as projected on the sky frame. Where an occultation by the solid body of the nucleus occurs, the shadow t...

The centaur Comet 29P/SW1 is a large 60-km object which appears to be uniquely active, almost certainly as a consequence of an extremely slow (57-d) rotation rate of its nucleus. It exhibits outbursts, which are explosive by nature and some of which appear to be associated with enduring cryovolcanoes. High-cadence precision photometry during 2014-2...

CBET 4313 available at Central Bureau for Astronomical Telegrams.

Comet 29P is possibly the largest (60 km) periodic comet known, and exhibits a uniquely high activity, outbursting 6-10 times each year despite occupying a near-circular orbit at an heliocentric distance of 5.8-6.2 au. The poster summarises some of the key aspects of current publications by this author and colleagues, which present new observationa...

BAA Section Director Dr Richard Miles explains the latest findings on the composition of comets from spaceprobes and professional studies, and describes his own contribution to the study of cometary outbursts, recently published in the journal Icarus.

Detailed morphological and photometric characterisation of comet 29P in the optical region is presented comprising: (a) multi-filter observations of the outburst coma in 2010–2012 with the 2.0-m Faulkes Telescopes (FT); (b) high-cadence, high-precision photometry in May–September 2014; and (c) HST observations in March 1996 (WFPC2/F702W filter). Ou...

Comet 29P/Schwassmann-Wachmann is located in a near-circular orbit some 6 au distant from the Sun. The nucleus is very large being ~50 km in size, and since its discovery in 1927 it has continued to exhibit sudden outbursts, brightening by typically 2-4 magnitudes several times each year. Nine reports in the literature of its rotation rate have fai...

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Amateur astronomers have increasingly been working with schools suggesting projects that have provided valuable scientific input to professional astronomers.

Asteroid 2014 AA collided with Earth: the second such object to be discovered prior to impact

An account of observations of the Herschel Space Observatory after it left its L2 position and was injected into an heliocentric orbit on 2013 June 17. The author extended the astrometric observational arc to 2013 September 24 when it was almost 0.1 au from Earth and 24th magnitude, ensuring it it would be relatively easy to recover in 2027 when ne...

On 2013 October 20.5, Hidetaka Sato discovered Comet C/2012 X1 in outburst, it having brightened by more than 5 magnitudes. This article describes follow-up imaging of structures in its expanding coma obtained by Denis Buczynski and by Nick James.

CBET 3687 available at Central Bureau for Astronomical Telegrams.

CBET 3672 available at Central Bureau for Astronomical Telegrams.

Available from the Minor Planet Center.

Available from the Minor Planet Center.

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Available from the Minor Planet Center.

Preliminary results are presented of several BAA observing campaigns conducted during 2009-2012 aimed at determining accurate phase curves of some 32 main-belt asteroids belonging to a range of taxonomic families. In particular, five of the objects studied are classed as Themis-family asteroids, namely; (24) Themis, (62) Erato, (379) Huenna, (996)...

In a previous paper [1], we show that melting of cometary ices can occur in the near-surface of some cometary nuclei where escape of volatiles is restricted by a microporous matrix held together by surface tension forces: the 'wetted layer'. Cometary grains are likely to be assemblages of submicrometre-sized particles, including clays porous at the...

In a previous paper [1], it was shown that melting of cometary ices will occur in the near-surface of some cometary nuclei where the escape of volatiles is restricted by a microporous matrix held together by surface tension forces: the so-called 'wetted layer'. In this paper, two distinct melting regimes are discussed, namely; (a) an 'hydrophobic'...

In a previous paper [1], it was shown that melting of cometary ices will occur in the near-surface of some cometary nuclei where the escape of volatiles is restricted by a microporous matrix held together by surface tension forces: the so-called 'wetted layer'. In this paper, two distinct melting regimes are discussed, namely; (a) an 'hydrophobic'...

Available from the Minor Planet Center.

CBET 3435 available at Central Bureau for Astronomical Telegrams.

Describes the first published account of an asteroid being eclipsed by the Earth's umbral shadow

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CBET 3289 available at Central Bureau for Astronomical Telegrams.

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CBET 3260 available at Central Bureau for Astronomical Telegrams.

CBET 3215 available at Central Bureau for Astronomical Telegrams.

CBET 3216 available at Central Bureau for Astronomical Telegrams.

CBET 3223 available at Central Bureau for Astronomical Telegrams.

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In this paper we review the relevant literature and investigate conditions likely to lead to melting of H2O ice, methanol (CH3OH) ice, ethane (C2H6) ice and other volatile ices in cometary nuclei. On the basis of a heat balance model which takes account of volatiles loss, we predict the formation of occasional aqueous and hydrocarbon liquid phases...

CBET 3137 available at Central Bureau for Astronomical Telegrams.

(1) We find that comet 107P/WH was active in 1949, 1979, 1992, 2005, and 2009. (2) Its age can be measured. We find T-AGE=4700 comet years, WB-AGE=7800 cy. (3) This is a methuselah comet very near to its dormancy phase, being temporarily rejuvenated due to a diminution of its perihelion distance. (4) We measured the diameter as Deffe=3.67\pm0.06 km...

CBET 3109 available at Central Bureau for Astronomical Telegrams.

CBET 3122 available at Central Bureau for Astronomical Telegrams.

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CBET 3082 available at Central Bureau for Astronomical Telegrams.

CBET 3083 available at Central Bureau for Astronomical Telegrams.

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CBET 2966 available at Central Bureau for Astronomical Telegrams.

CBET 2978 available at Central Bureau for Astronomical Telegrams.

CBET 2950 available at Central Bureau for Astronomical Telegrams.

Observational evidence is presented which demonstrates that object 2010 KQ is artificial in nature and is almost certainly the upper rocket stage of a Russian Moon probe. The only possibilities identified are the rocket stages associated with the launches of Luna-1 (1959 January 2), Luna-4 (1963 April 2) or Luna-23 (1974 October 28). The Minor Plan...

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Available from the Minor Planet Center.

We predict the occurrence of aqueous and hydrocarbon liquid phases in subsurface regions of comet nuclei dependent on heliocentric distance. Microporosity and the formation of a stabilization layer in the near-surface are prerequisites for liquid phase formation. Characteristics favoring subsurface melting are discussed including pore-size distribu...

In a previous paper [1] we showed from detailed considerations of the physical and chemical characteristics of comet nuclei how aqueous and hydrocarbon (HC) liquid phases can form and persist in near-surface regions, the composition of which varies with depth. Here we describe how liquid-phase processes may underlie outbursts of the comets 1P/Halle...

CBET 2849 available at Central Bureau for Astronomical Telegrams.

Available from the Minor Planet Center.

Available from the Minor Planet Center.

CBET 2822 available at Central Bureau for Astronomical Telegrams.

IAUC 9227 available at Central Bureau for Astronomical Telegrams.

CBET 2768 available at Central Bureau for Astronomical Telegrams.

CBET 2752 available at Central Bureau for Astronomical Telegrams.

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On 2010 December 11.5, Steve Larson of the Lunar and Planetary Laboratory, University of Arizona, observing with the 0.68m f/1.8 Schmidt telescope of the Catalina Sky Survey, found that the minor planet (596) Scheila appeared to be exhibiting comet-like behaviour. This unique phenomenon is thought to be the result of a high-speed collision between...