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Low atmospheric reconnections associated with an eruptive flare

Yong-Jae Moon(1), Jongchul Chae(2), Yong-Jae Moon(1), Jongchul Chae(2), Young-Deuk Park(1)Young-Deuk Park(1)

1: Korea Astronomy and Space Science Institute1: Korea Astronomy and Space Science Institute2: Seoul National University 2: Seoul National University

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Outline

We present anWe present an observational study of the observational study of the filament-flare-CME event on Nov. 24, 2000 filament-flare-CME event on Nov. 24, 2000 with the following topics:with the following topics:

1. Preflare Activity 1. Preflare Activity

2. Preflare Activity and Canceling Magnetic 2. Preflare Activity and Canceling Magnetic Feature (CMF)Feature (CMF)

3. Pre-flare Activity and Filament Eruption 3. Pre-flare Activity and Filament Eruption

4. Filament Kinematics and CME4. Filament Kinematics and CME

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Advantages of Present Study

Near simultaneous observation of MDI, TRACE Near simultaneous observation of MDI, TRACE 1600, BBSO H-alpha centerline and bluewing : 1-min 1600, BBSO H-alpha centerline and bluewing : 1-min time cadence and 1’’ spatial resolutiontime cadence and 1’’ spatial resolution

Initial filament kinematics is well examinedInitial filament kinematics is well examined

(10-160km/s for the first twenty minutes)(10-160km/s for the first twenty minutes) We study the relationship among preflare We study the relationship among preflare

brightenings, canceling magnetic features, and initial brightenings, canceling magnetic features, and initial filament kinematicsfilament kinematics

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1. Preflare Activity

SOHO/MDISOHO/MDI

H-a centerH-a center

H-a blueH-a blue

TRACE 1600TRACE 1600

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Two brightenings (B1 and B2) are just near one Two brightenings (B1 and B2) are just near one footpoint of the filament and cospatial with two footpoint of the filament and cospatial with two CMFsCMFs

SOHO/MDISOHO/MDI

H-a centerH-a center

TRACE 1600TRACE 1600

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Small-scale Eruptive Events

Recurrent small-scale UV eruptive events near the Recurrent small-scale UV eruptive events near the one footpoint of the filament near the eruption time.one footpoint of the filament near the eruption time.

1) Projected speed : 140 km/s1) Projected speed : 140 km/s

2) It may be a result of low atmosphere reconnection.2) It may be a result of low atmosphere reconnection.

TRACE 1600TRACE 1600

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TRACE EUV loop eruption

Sturruck et al. (2001)Sturruck et al. (2001)

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2. Canceling Magnetic Features

Sonic filter : 4km/sSonic filter : 4km/s Flux variations of two Flux variations of two

CMFs CMFs 1) A tendency : first 1) A tendency : first

increase and then increase and then decreasedecrease

: imply “ First : imply “ First emergence and then emergence and then

reconnection”reconnection” 2) Brightenings (B1,B2) 2) Brightenings (B1,B2)

occurred in the flux occurred in the flux decrease phasedecrease phase

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3. Preflare Activity and Eruption From BBSO H-alpha From BBSO H-alpha

data, we derived data, we derived ejection speedsejection speeds

Eruption started at Eruption started at 21:30 UT with 10km/s, 21:30 UT with 10km/s, which is 10-20 minutes which is 10-20 minutes earlier than the flare earlier than the flare onsetonset

Pre-flare brightening Pre-flare brightening (near 21:32 UT) is (near 21:32 UT) is coincident with the coincident with the eruption time.eruption time.

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4. Filament Kinematics and CME

The maximum The maximum acceleration occurs acceleration occurs near the peak time of near the peak time of the the flare. the the flare.

Initial exponential Initial exponential growth : may be growth : may be explained by flux explained by flux injection (Chen) or injection (Chen) or mass drainage (Low) mass drainage (Low) instabilities(Forbes)instabilities(Forbes)

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EIT Running Difference Image

A direction of the EIT wave feature seen in the last A direction of the EIT wave feature seen in the last image : consistent with the direction of a LASCO image : consistent with the direction of a LASCO CME seen at 22:06CME seen at 22:06

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LASCO Running Difference Image

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Summary There are noticeable preflare brightenings which are There are noticeable preflare brightenings which are

located near one footpoint of the filament.located near one footpoint of the filament. They are most evident in Trace UV and H-alpha They are most evident in Trace UV and H-alpha

images and are cospatial with CMFs.images and are cospatial with CMFs. The CMFs show a tendency of “flux increase and then The CMFs show a tendency of “flux increase and then

decrease” and they seem to be triggered by flux decrease” and they seem to be triggered by flux emergence and/or motions.emergence and/or motions.

Preflare activity, CMFs, and UV eruptive events may Preflare activity, CMFs, and UV eruptive events may imply low-atmosphere reconnections.imply low-atmosphere reconnections.

One major pre-flare brightening responsible for the One major pre-flare brightening responsible for the flare precursor is coincident with the eruption time.flare precursor is coincident with the eruption time.

The above activities may play important role in the The above activities may play important role in the onset of the filament eruption.onset of the filament eruption.

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Future Works From a statistical study of filament-flare-CME events, From a statistical study of filament-flare-CME events,

we will address several questions:we will address several questions: 1. What is preflare activity ?1. What is preflare activity ? 2. Is CMF responsible for flare precursor ?2. Is CMF responsible for flare precursor ? 3. Is statistically significant CMF frequency3. Is statistically significant CMF frequency near near

eruption time ?eruption time ? 4. Is there any difference between eruptive and non-4. Is there any difference between eruptive and non-

eruptive events ?eruptive events ? 5. What is the relationship among preflare activity, 5. What is the relationship among preflare activity,

CMFs, flare precursor, and filament eruption ? CMFs, flare precursor, and filament eruption ? 6. What is the implication on the CME onset time ?6. What is the implication on the CME onset time ? Solar-B and SDO may give more definite answers.Solar-B and SDO may give more definite answers.

19:46

1999 Jan 16 M1.2

Yohkoh Soft X-ray TRACE 1600 Å

Foot point Brightening

Sigmoid and eruption

• • Flaring time Flaring time 19:50 ~ 20:02 19:50 ~ 20:02

• • Pre-flare time Pre-flare time 19:4619:46