• Preventive Nutrition and Food Science
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• 제11권1호
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• pp.25-30
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• 2006

It is of utmost importance to feed the current world population by improving agricultural production with newer varieties of food crops, but what is still more important is to add nutrition into the food. Some of the plants, which are currently growing in the wastelands, contain certain phytochemicals which add to their neutraceutical and health value. These plants contain secondary metabolites which enhance the over all metabolic functions of the body. Withasteroids are one of such phytochemicals. These chemicals are almost exclusively found in plants of the Solanaceae family; one of which, Physalis minima, contains several with asteroids. The aerial parts and roots of P. minima have been found to contain several steroids, identification of which is been discussed in this paper. These with asteroids contribute to the functional value since incorporation of withanolides in the diet may prevent or decrease the growth of tumors in humans.

• 천문학회보
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• 제35권1호
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• pp.87.1-87.1
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• 2010

Main-belt comets (hereafter MBCs) are one of the hottest topics in the solar system astronomy. They are objects orbiting in the main asteroid belt which show cometary activity. Unlike most comets, which spend most of their orbit beyond 5AU from the Sun, MBCs follow near-circular orbits within the asteroid belt that are indistinguishable from the orbits of major population of the asteroids. P/2010 A2, the fifth MBC, was discovered by on January 6, 2010 by Lincoln Near-Earth Asteroid Research. It passed its perihelion at 2.01AU on December 3, 2009, about a month before it was discovered. With an aphelion of only 2.6 AU, P/2010 A2 spends all of its time inside of the frostline ~2.7 AU. We made observations of P/2010 A2 with Nishi-Harima Astronomical Observatory 2-m telescope only a week after the discovery. From the observed images, we found that the dust cloud was composed of large particles (>1mm) impulsively ejected between March and June, 2009. No coma was detected by our observations, suggesting that this object was no longer active. Consequently, we conjecture that these dust particles could be released by the impact collision among asteroids.

• 천문학회보
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• 제41권1호
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• pp.81.4-82
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• 2016

Recent analysis on asteroidal thermophysical property revealed that there is a tendency that their thermal inertia decrease with their sizes at least for main belt asteroids. However, little is known about the thermal properties of comet-like bodies. In this work we utilized a simple thermophysical model to calculate the thermal inertia of a bare nucleus of comet P/2006 HR30 (Siding Spring) and an asteroid in comet-like orbit 4015 Wilson-Harrington from AKARI observation data. It is also shown that the determination of their thermal inertia is very sensitive to their spin vector, while the diameter is rather easy to be constrained to a certain range by combining multi-wavelength observational data. Thus, we set diameter and hence the geometric albedo as fixed parameters, and inferred the spin vector and thermal inertia of the targets. Further detailed analyses on these cometary bodies will shed light on our understanding of the detailed surfacial characteristics of them.

• 천문학회보
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• 제46권2호
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• pp.57.2-57.2
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• 2021

An asteroid is important for understanding the condition of our solar system in early-stage because an asteroid, considered as a building block of the solar system, preserves the information when our solar system was formed. It has been continuously flowing into the near-Earth space, and then some asteroids have a probability of impacting Earth. Some asteroids have valuable minerals and volatiles for future resources in space activity. Korean government clarified, in the 3rd promotion plan for space activity, an asteroid sample return mission by the mid-2030s. However, it is almost impossible to do so based on only a single experience of an exploration mission to the Moon, Korea Pathfinder Lunar Orbiter, which will be launched in mid-2022. We propose a Rendezvous Mission to Apophis(RMA), beneficial in terms of science, impact hazardous, resource, and technical readiness for the space exploration of Korea.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1999년도 공동 춘계학술대회
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• pp.58.2-58
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• 1999

No Abstract, See Full Text

• 천문학회보
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• 제34권1호
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• pp.76.1-76.1
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• 2009

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2009년도 한국우주과학회보 제18권1호
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• pp.40.1-40.1
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• 2009

• 천문학회보
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• 제41권1호
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• pp.55.2-56
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• 2016

The spin states of asteroids is regarded as an important clue to understand not only the physical property of an individual object but also the dynamical evolution of the of the population as a whole. Single asteroids can be broadly classified into two separate groups according to their rotational states; Principal Axis (PA) and Non-Principal Axis (NPA) rotators. To date, lightcurve observations have been carried out mostly for PA asteroids. However, discovery of NPA objects has recently been increased due to new observing techniques, and this is the reason why rotational properties of NPA rotators became an issue. As a DEEP-South pilot study for NPA, we selected two targets, 5247 Krolv (1982 UP6) and 14764 Kilauea (7072 P-L) considering their Principal Axis Rotation (PAR) code and visibility. Observations were made between Jan. and Feb. 2016 for 17 nights employing Korea Microlensing Telescope Network (KMTNet) 1.6 m telescopes installed at SSO and SAAO using DEEP-South TO (Target of Opportunity) mode. To obtain lightcurves, we conducted time-series photometry using Johnson-Cousins R-filter. Multi-band photometry was also made with BVRI filters at the same time, for taxonomy. Their preliminary lightcurves and approximate mineralogy will be presented.

• 천문학회보
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• 제41권1호
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• pp.49.1-49.1
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• 2016

Solar System has evolved with numerous collisions among asteroids. Ancient catastrophic collisions of large parent bodies led the formation of asteroid families and relevant dustband structures up to the present day, and it would be interesting to address a question - "what happens if an asteroid collides with another asteroid?" Recent discoveries of "active asteroids" in the main-belt have attracted interest for their potential to witness a catastrophic collision in the current Solar System. So far, however, there is no direct evidence for catastrophic collision on active asteroids while several objects have been confirmed for other mechanisms (e.g., 596 Scheila for impact cratering, P/2013 R3 and P/2013 P5 for rotational breakup). The most potential candidate for catastrophic collision could be a sub-km active asteroid P/2010 A2, which is still controversial on its driving mechanism, but if confirmed, would have made P/2010 A2 the unique example of catastrophic collision on the current main asteroid belt. In this presentation, we revisit all of archival data of P/2010 A2 in a combination with our own observation using Subaru/Suprime-Cam on 2011 June, where we have a great benefit of a large orbital coverage. We found a grain size dependence of dust ejection velocity from P/2010 A2 (a power-law size distribution with an index of k~ -1/10), which is favorable to a catastrophic disruption scenario in agreement with laboratory impact experiments. At this conference, we plan to provide our understanding of the morphology of P/2010 A2 through a perspective of catastrophic collision.

• 천문학회보
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• 제39권1호
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• pp.66.2-66.2
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• 2014

We carried out photometric observations of Maria family asteroids during 134 nights spanning from July 2008 to May 2013, and derived synodic rotational periods for 51 objects including obtained periods of 34 asteroids for the first time. In this study, we found that there is a significant excess of fast and slow rotators. The one-sample Kolmogorov-Smirnov test confirms that the spin rate distribution is not consistent with the Maxwellian at a 92% confidence level. From the correlations between rotational period, amplitude of lightcurve, and size, we conclude that rotational properties of Maria family have been changed considerably by the non-gravitational force such as the Yarkovsky and the YORP effect. Using the lightcurve inversion method, we successfully determined the pole orientation for the 13 Maria members, and found the excess of prograde objects versus retrograde with a ratio ($N_p/N_r$) of 3. This implies that retrograde rotators could have been ejected by the 3:1 resonance to the inner Solar System since the generation of Maria family. We estimate that approximately 37 - 75 kilometer-sized Maria asteroids have entered to near-Earth space every 100 Myr.