1. 2010 – 20391 Ji-Beom Ham OUTBURST EVENT WITH LSST Giant Telescope Science 2011 Spring

2. CONTENTS What is outburst event on solar system objects? What is LSST? Why LSST?

3. WHAT IS OUTBURST?

4. LET’S SEE THE MOVIE FIRST This movie is related with asteroid 596 Scheila recently experiencced ou tburst event. http://www.youtube.com/watch?v=qchvgRUDUzA&feature=player_embedded#at=129 ASTEROID 596 SCHIELA

5. WHAT IS OUTBURST Cometary outbursts have aroused astronomer’ curiosity since 1927 when a comet 29P/Schwassmann-Wachmann 1 was discovered. Comet C/1961 R1 (Humason) experienced outburst on 1964. Comet 1P/Halley also experienced strong outburst activity on Feb 12, 1992. Many people thought about outburst mechanism, 1) Collision with the interplanetary bodies(Fernandez 1990, Hughes 1991) 2) Collision with the meteoroid streams (Matese and Whitman 1994) 3) Solar flare(Intrilligator and Dreyer 1991) 4) Internal cause like the presence of ice which are much more volatile than H20, such as CO or CO2 ( Sandford and Allmandola 1988)

6. COMET 17P/HOLMES OUTBURST Outburst of comet 17P/Holmes is exceptional. Its apparent magnitude was increased by about a million times, 17 mag to 2.5 mag. Outburst date was 2007 Oct. 25 Recent paper proposed the scenario of CO driven explosion with simulation. (Kossacki 2011) Even though, we still don’t know how this object shows such a massive brightness enhancement.

7. ASTEROID 596 SCHEILA OUTBURST This object was originally main-belt asteroid, but suddenly shows the cometary activity. This object seems to be experience the outburst early December, 2010. As shown in the movie, outburst of this object seems to triggered by collision with interplanetary bodies.

8. WHAT IS LSST?

9. LSST

10. WHAT DOES “SYNOPTIC” MEANS synoptic [sinptik / -np-] 1. 개요의, 대요의, 개관의. 2. ( 종종 S- ) 공관 복음서 ; = synoptist. synoptic This word derives from the Greek word "Synopsis" and refers to looking at all aspects of something. In LSST, this word used in several aspects. Billions of objects will be imaged in six colors It will be observing beyond z ~ 3 galaxies. Several billion galaxies and ten billion stars will be cataloged. This survey over half the sky will also catalog changes in the intensity or color of these sources.

11. BRIEF INTRODUCTION OF LSST WIDE, FAST, DEEP 8.4 m – size Telescope Excellent 3.2G pixels(3.2 billion pixels) CCD. 9.6 square degree(3.5 degrees in diameter) field of view with excellent image quality because of its huge aperture. Taking 800 images per every night. Scanning whole sky every 3-days Built in Cerro Pachón, Chille The LSST is scheduled to see first light in 2014 Six – Filters, U, G, R, I, Z and Y.

12. IMPROVEMMENT DSS: digitized photographic plates DSS: digitized photographic plates Sloan Digital Sky Survey Sloan Digital Sky Survey Deep Lens Survey Deep Lens Survey LSST LSST One quarter the diameter of the moon

13. IMPROVEMMENT Factor of 2 deeper Factor of 2 better angular resolution 6 colors Entire visible sky (full hemisphere) 1000 times the area No artifacts (blooming, diffraction spikes)

14. LSST TIMELINE

15. LSST SITE At Meeting on January 2005, three candidates for LSST have determined. Finally, Cerro Pachón, a mountain peak in northern Chilé, has been selected as the site for LSST

16. LSST TELESCOPE Optical Configuration: 3-mirror modified Paul-Baker Final f-ratio: f/1.234 Mount configuration: Alt - Azimuth Primary mirror aperture: 8.4 m Step-and-settle time: 5 seconds

17. LSST CAMERA Pixel count: 3.2 Gpixels Readout time: 2 sec Dynamic range: 16 bits Nominal exposure time: 15 seconds Plate scale: 50.9 microns/arcsec Filter set (FWHM points - nm) u: 330nm to 403nm g: 403nm to 552nm r: 552nm to 691nm i: 691nm to 818nm z: 818nm to 922nm y: 950nm to 1070nm

18. DATA MANAGEMENT 30 Tbytes per every night. Database over the ten years of operations of 60 PB for the raw images. The total data volume after processing will be several hundred PB.. 100 TFlops of computing power is needed. 플롭스 ( FLOPS, FL oating point OP erations per S econd) 는 컴퓨터의 성능을 수치로 나타낼때 주로 사용되는 단위이다. 컴퓨터 단위 초당 부동소수점 연산이라는 의미로 컴퓨터가 1 초동안 수행할 수 있는 부동소 수점 연산의 횟수를 기준으로 삼는다. 상위 단위와 하위 단위로 국제단위계의 표준 접두어를 사용하며, 슈퍼 컴퓨터의 성능을 나타낼 경우에는 테라플롭스 (1×10 12 플롭스 ) 가 주로 쓰인다. 2010 년 10 월 현재 가장 빠른 슈퍼컴퓨터는 톈허 -1A 로, 그 속도는 2.507PFLOPS(2.507×10 3 TFLOPS) 이다. 부동소수점 국제단위계 슈퍼 컴퓨터 테라 톈허 -1A

19. WHY LSST?

20. REPRESENTATIVE FOUR KEY SCIENCE Nature of Dark Energy Measuring weak gravitational lensing in the deep sky to detect signatures of dark energy and dark matter. Solar System Survey Mapping small objects in the solar system, particularly near-Earth asteroids and Kuiper belt objects. Optical Transient Detecting transient optical events such as novae and supernovae. Galactic Map

21. NEAR EARTH OBJECTS : IMPACT HAZARD

22. OPTICAL TRANSIENT OBS. IN SOLAR SYSTEM Studies of the distribution of orbital elements for about 100,000 NEOs, several million main-belt asteroids, 100,000 Jovian troijan asteroids, Centaurs and TNO as a function of color and size. Extremely distant solar system: the search for objects with perihelia a several hundred AU (e.g. Sedna will be observable to 130 AU). Multi-color studies of interplanetary (zodiacal) dust with high spatial resolution. Unbiased and complete census of both Jupiter-family and Oort-cloud comets; 6-band sub- arcsecond spatial profiles to a faint surface brightness limit, temporally resolved activity

23. OUTBURST MONITORING For the study of outburst event of comet or asteroid, we can easily find it. Using LSST data, It is possible to monitor where and when outburst event happened In usual case, it is almost impossible to find the data before the outburst. However, in the case of LSST, finding a data taken before the outburst is not so difficult.

24. TAXONOMIC TYPE STUDY Taxonomic type study is also important, because this type tells us the chemical composition of asteroids. Since LSST use 6 color observation, we can determine the taxonomic type.

25. AVAILIVILITY

26. THANK YOU FOR LISTENING