SonotaCo.JP
SonotaCo Network Japan Forum
SonotaCo.JP Forum Index
homeTop Page  FAQFAQ   検索検索   メンバーリストメンバーリスト   ユーザーグループユーザーグループ   登録する登録する 
 プロフィールプロフィール   プライベートメッセージをチェックするプライベートメッセージをチェックする   ログインログイン 

Fireball Spectrum
ページ移動 前へ  1, 2, 3 ... 10, 11, 12 ... 19, 20, 21  次へ
 
新しいトピックを投稿   トピックに返信    SonotaCo.JP Forum Index -> UFOCapture BBS in English
前のトピックを表示 :: 次のトピックを表示  
投稿者 メッセージ
Marian



登録日: 2015.10.12
記事: 8

記事日時: Sat Sep 03, 2016 3:37 am    記事の件名: 引用付きで返信

Hello everybody! Hello Martin! (we have talked in the past year on e-mail,thanks for your help)
My name is Marian,I am from Ukraine,Ukrainian group video meteor observations.
This is my first spectrum.Camera Wat 902 H2 Ultimate,lens Rainbow H6X-8 17 15mm,10.2 A\pixel.I use IRIS and RSpec. Perseid -2.9m.



M20160812_235601_Khmelnitsk_M2P.jpg
 説明:
 ファイルサイズ:  37.67 KB
 閲覧数:  8477 回

M20160812_235601_Khmelnitsk_M2P.jpg



41.jpg
 説明:
 ファイルサイズ:  65.23 KB
 閲覧数:  8477 回

41.jpg


トップに戻る
ユーザーのプロフィールを表示  
Martin Dubs



登録日: 2014.03.04
記事: 56

記事日時: Tue Sep 06, 2016 6:16 am    記事の件名: 引用付きで返信

Hello Marian,

nice spectrum! Could you tell us a liittle more about how you analysed the spectrum. Did you use IRIS for the correction of dispersion as I described it (e.g. here: http://www.meteorastronomie.ch/spektroskopie.html)? The spectrum is well resolved and correctly assigned as far as I can tell. RSpec seems to do a good job.

Regards, Martin
トップに戻る
ユーザーのプロフィールを表示   投稿者のウェブサイトに移動
Marian



登録日: 2015.10.12
記事: 8

記事日時: Tue Sep 06, 2016 6:41 pm    記事の件名: 引用付きで返信

Yes,I use IRIS - Correct distortion.But I have many questions.I don't know how can I get
coefficients for my own camera.I use your coefficient,it helps a bit but not perfectly.
In RSpec I use non-linear calibration.Good visible lines help me to do it well - Mg 4481,Fe 5270,Na 5890,O 7774,second Order of Mg triplet...



Sp.png
 説明:
 ファイルサイズ:  190.57 KB
 閲覧数:  8431 回

Sp.png


トップに戻る
ユーザーのプロフィールを表示  
Marian



登録日: 2015.10.12
記事: 8

記事日時: Tue Sep 06, 2016 6:48 pm    記事の件名: 引用付きで返信

If BillW do not mind - to compare my specturm and Bill's sporadic fireball


=.png
 説明:
 ファイルサイズ:  28.79 KB
 閲覧数:  8428 回

=.png


トップに戻る
ユーザーのプロフィールを表示  
Bill W



登録日: 2012.02.13
記事: 182
所在地: Glasgow

記事日時: Thu Sep 08, 2016 4:12 am    記事の件名: 引用付きで返信

Hi Marian,
No problem, that is nice work!
It beautifully shows the real power of spectroscopy. We can now compare samples to each other which is something that could not be done easily in the past.
Normal integrated light observations just do not offer this possibility.
This has changed meteor observing completely in only a couple of years.
Cheers,
Bill.
トップに戻る
ユーザーのプロフィールを表示   投稿者のウェブサイトに移動
Marian



登録日: 2015.10.12
記事: 8

記事日時: Tue Sep 13, 2016 7:36 am    記事の件名: 引用付きで返信

Thanks Bill!
While I studied the Martin's "Processing meteor spectra" I caught another meteor.It is sporadic,-2.5m,order -1.I tried to identify famous lines



35b fin.png
 説明:
 ファイルサイズ:  10.09 KB
 閲覧数:  8341 回

35b fin.png



1.jpg
 説明:
 ファイルサイズ:  25.56 KB
 閲覧数:  8340 回

1.jpg




最終編集者 Marian [ Tue Sep 13, 2016 8:16 am ], 編集回数 1 回
トップに戻る
ユーザーのプロフィールを表示  
Marian



登録日: 2015.10.12
記事: 8

記事日時: Tue Sep 13, 2016 8:13 am    記事の件名: 引用付きで返信

I caught a spectra of Moon and compared it with those of my meteors .If I am right, I see telluric lines "B" 02,H2O, "A" O2 in all my spectra.It is not strange,but it is new for me.


moon.png
 説明:
 ファイルサイズ:  12.53 KB
 閲覧数:  8337 回

moon.png


トップに戻る
ユーザーのプロフィールを表示  
Bill W



登録日: 2012.02.13
記事: 182
所在地: Glasgow

記事日時: Tue Sep 20, 2016 5:31 am    記事の件名: 引用付きで返信

Hi Marian,

The moon comparison is very good! Nicely shows the atmospheric absorption bands.

As another example of the power of spectroscopy, I had a close look at your spectrum again and I think your Perseid might not be a Perseid after all...

Your spectrum from the 2016 08 12 is really well dispersed but Perseids are fast moving meteors that tend to ablate higher up in the atmosphere. This gives them a distinct green colouration at the start as seen in photographic images. It comes from the 5577A (557.7nm) forbidden line of oxygen, the same colour that is seen in the aurora.

It is only seen above ~110km so it shows up as a distinct line at the start of the spectum and generally fades as the other lines brighten towards the end of the meteor. As the meteor travels lower into the atmosphere the emission from the forbidden O line gets "quenched" (in the jargon) and can no longer be seen.

If you examine your spectrum between the 517nm Mg line and the 589nm Na lines there is nothing distinct there so no forbidden O emission. So immediately we know it must either be an unusual Perseid as no 557.7nm line means it is travelling more slowly than your average Perseid and ablating lower in the atmosphere. Or it was not a Perseid and just had a co-incidental path.

An intriguing result and another illustration of the diagnostic fingerprinting we can now do.

cheers,
Bill.
Very Happy
トップに戻る
ユーザーのプロフィールを表示   投稿者のウェブサイトに移動
Bill W



登録日: 2012.02.13
記事: 182
所在地: Glasgow

記事日時: Tue Sep 20, 2016 5:41 am    記事の件名: 引用付きで返信

Hi again,

Attached is an image from an article I wrote explaining why we see the colours we do. (especially in images of Perseids, greenish at the start, through white then reddish at the end.)

You can see the faint but distinct 557.7nm line here which is missing from yours.

What I call "comparative meteor spectroscopy" is a very useful tool especially when there are limited observations as it can give us some clues to the speed and thus a guide to ablation height of the meteor.

Cheers,
Bill.



Forbidden emission example.jpg
 説明:
 ファイルサイズ:  77.02 KB
 閲覧数:  8275 回

Forbidden emission example.jpg


トップに戻る
ユーザーのプロフィールを表示   投稿者のウェブサイトに移動
Marian



登録日: 2015.10.12
記事: 8

記事日時: Tue Sep 20, 2016 10:47 pm    記事の件名: 引用付きで返信

Hi Bill!
Thank you very much for interesting information.You are right,there is no distinct line 557.7 nm in my meteor.But UFO Orbit says - it is perseid.It has Vg 58.2 km,H1 113 km.this is for my part of analyze,but...Unfortunaly second station had problems with Fps on his camera at those days,so total quality for this meteor is only Qo.Therefore I can't be sure in my data.



MAP.jpg
 説明:
 ファイルサイズ:  112.85 KB
 閲覧数:  8246 回

MAP.jpg



B20160812_235600GMAP.jpg
 説明:
 ファイルサイズ:  81.09 KB
 閲覧数:  8245 回

B20160812_235600GMAP.jpg


トップに戻る
ユーザーのプロフィールを表示  
Martin Dubs



登録日: 2014.03.04
記事: 56

記事日時: Wed Sep 21, 2016 7:03 am    記事の件名: 引用付きで返信

Hi Bill and Marian,

I looked at my Perseid spectra from last year. I captured 3 Perseids with good orbits (meaasured by at least 4 stations). None of them showed the oxigen 557.7nm forbidden line. They were all bright (-4m to-6m), so I assume they evaporated at lower altitude than smaller meteors (starting height around 110 km, in one case 120 km, but spectrum only from later part of trail). In the enclosed document you find the spectra and notes on the processing and other information. In the meantime I have streamlined the pocessing somewhat. In one case I superimposed Bills spectrum with higher resolution, showing the 557.7nm line, absent in all my spectra. I cannot tell if this result is because of lower sensitivity of my images.

Marian, do you make any progress with my calibration method?

Regards, Martin



Meteor spectra 201508Perseids.pdf
 説明:
processing log of 2015 Perseids

ダウンロード
 ファイル名:  Meteor spectra 201508Perseids.pdf
 ファイルサイズ:  546.29 KB
 ダウンロード回数:  265 回

トップに戻る
ユーザーのプロフィールを表示   投稿者のウェブサイトに移動
Bill W



登録日: 2012.02.13
記事: 182
所在地: Glasgow

記事日時: Wed Sep 21, 2016 7:28 am    記事の件名: 引用付きで返信

Hi,
The first two images in this thread were of extremely bright Perseids and they too don't show the 557.7nm lines.
Though the third does have it (faintly)
Maybe there is some critical cutoff of meteoroid brightness (mass) in combination with a given velocity that dictates how the particle behaves in the region above 110km.
Another interesting thing to explore.
Regards,
Bill.
トップに戻る
ユーザーのプロフィールを表示   投稿者のウェブサイトに移動
Marian



登録日: 2015.10.12
記事: 8

記事日時: Fri Sep 23, 2016 2:04 am    記事の件名: 引用付きで返信

Hi all!
Martin,I am still reading and thinking.
I have a question. I compared my solar spectrum and the spectra of meteors. The lines На аnd Hb look like the same. It is a coincidence or not?(Sun is red line,meteor is blue line).



=.png
 説明:
 ファイルサイズ:  19.93 KB
 閲覧数:  8186 回

=.png


トップに戻る
ユーザーのプロフィールを表示  
Bill W



登録日: 2012.02.13
記事: 182
所在地: Glasgow

記事日時: Tue Oct 04, 2016 2:40 am    記事の件名: 引用付きで返信

Hi Marian,

That is a good question.

Ceratinly a lot of meteors show the Ha line at 656nm. But I don't know about Hb for certain.

Due to the resolution limits we work at and the noise in the images, sometimes lines can appear that aren't real.

There may well be a known line from some element at that wavelength but it is not a guarantee that it is really there from the meteor.

This is part of the challenge as we have no beforehand information about our "sample" and there are a lot of variables to take into consideration.

Maybe Martin or another observer can confirm Hb emission.

Cheers,
Bill.
トップに戻る
ユーザーのプロフィールを表示   投稿者のウェブサイトに移動
前田



登録日: 2004.09.01
記事: 2754
所在地: Miyazai JAPAN (E131.4, N31.8)

記事日時: Fri Nov 25, 2016 10:45 pm    記事の件名: small fairball 引用付きで返信

Hi all,
I captured a small fairball ( Mag. -2.5, dur. 1.7s ) tonight. It may belong Taurids.

In my location, it had been cloudy and rainy days in summer and autumn.
But it returned clear sky in winter !

Regards,
Koji



M20161125_212834_JPMZ1_HEPc11.jpg
 説明:
SONY a7s + 24 mm + 600 grooves grating
 ファイルサイズ:  76.51 KB
 閲覧数:  7686 回

M20161125_212834_JPMZ1_HEPc11.jpg


トップに戻る
ユーザーのプロフィールを表示   投稿者のウェブサイトに移動
特定期間内の記事を表示:   
新しいトピックを投稿   トピックに返信    SonotaCo.JP Forum Index -> UFOCapture BBS in English All times are GMT + 9 Hours
ページ移動 前へ  1, 2, 3 ... 10, 11, 12 ... 19, 20, 21  次へ
Page 11 of 21

 
移動先:  
新規投稿: 不可
返信投稿: 不可
記事編集: 不可
記事削除: 不可
投票参加: 不可
このフォーラムで添付ファイルを投稿 できません
このフォーラムでファイルをダウンロード できます


Powered by phpBB © 2001, 2005 phpBB Group
Copyright ©2004 SonotaCo Network. All Rights Reserved.