親子觀星會

==
 C/2021 A1 (Leonard)彗星  2022/1/3過近日點


C/2021 A1 (Leonard)   再變亮
----
C/2021 A1 (Leonard)  可能 ??is fading and acting strange
==
C/2021 A1 (Leonard)  亮度上升中
==

C/2021 A1 (Leonard)     broken piece
==

1/3 彗星過近日點
==
C/2021 A1 (Leonard) 再變亮

==
C/2021 A1 (Leonard) 在有跟沒有分裂之間

==
C/2021 A1 (Leonard)

It is expected to make its closest approach to the sun on January 03, 2022.

https://en.wikipedia.org/wiki/C/2021_A1_(Leonard)

https://www.minorplanetcenter.net/mpec/K21/K21A99.html



2021/ 12/15  peak Mag =4
FROM FACEBOOK   Comets-and-Asteroids

https://m.facebook.com/Comets-and-Asteroids-140234731687/

http://www.aerith.net/comet/catalog/2021A1/2021A1.html

(http://www.aerith.net/comet/catalog/2021A1/mag.gif)

(https://scontent.ftpe8-1.fna.fbcdn.net/v/t1.0-9/136056541_4958440860893346_8098602773776831594_n.jpg?_nc_cat=105&ccb=2&_nc_sid=dbeb18&_nc_ohc=sdGq8Sp31QoAX_go1R2&_nc_ht=scontent.ftpe8-1.fna&oh=10ff73a4a86788811f244487c3a49a81&oe=601F513B)

from:
https://www.facebook.com/groups/387657394723672/?multi_permalinks=1834669493355781&notif_id=1610284958512027&notif_t=feedback_reaction_generic_tagged&ref=notif

新彗星！！！
New comet!!!
名字：Leonard
編號：C/2021 A1
發現：今年一月三號（2021/1/3）G. J. Leonard先生用了檸檬山天文台（亞利桑那州）的望遠鏡，確認了一顆新彗星！其實這顆彗星在去年4/11就拍到了，但那時太暗，沒有觀測到明顯的彗星特徵（彗髮），所以拖了9個月才確認。
亮度預測：目前有看過很多的預測結果，最樂觀的預測上看0等，而目前普遍主流的預測只有4等。
p.s.注意！彗星亮度的預測其實就和天氣一樣，時間越接近會越準確，因此現在變動幅度仍大，但祂仍舊是值得注意的一顆彗星。
特殊點－極靠近金星飛掠：根據目前的觀測結果所算出來的軌道，屬於雙曲線軌道，意即他這次飛過可能就不會再回來了，2022年一月三號將抵達近日點，距太陽約0.6天文單位（AU），距離地球最近將達約0.23AU，木星約0.29AU，不過這不是特殊點，他距離金星最近預計將只有0.0001AU！！！大約只有1.5萬公里！
p.s.上次有彗星這麼靠近行星是2013年發現，2014年飛掠火星的C/2013 A1（賽丁泉彗星），當時距離火星有0.001AU。
感謝吳柏賢大大幫忙提供了一些相關資料~

//===========
JPL的網頁 和金星的最近距離是0.0283AU 左右 , 更新一下和金星的最近距離
https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=C%2F2021%20A1;orb=0;cov=0;log=0;cad=1#cad

https://www.tam.museum/astronomy/forecast_detail.php?lang=tw&id=499

C/2021 A1 (Leonard)是一顆長週期彗星，於2021年1月3日被G.J.倫納德在萊蒙山天文台發現，是2021年發現的第一顆彗星，當時它距離太陽5AU（約7.5億公里），並且還要一年多才會抵達近日點，目前的總亮度僅有18等左右，預計於2021年12月13日最接近地球且最亮，粗估屆時總亮度將達到1等以上，可能會是2021年最明亮的彗星，並且有機會於天亮前以肉眼見到它的身影，若有興趣拍攝者，大約在10月中起可利用中大型望遠鏡看見它，實際經過的大略路徑請見下圖。

(http://www.tam.museum/astronomy/htmlFiles/images/stellarium-011.jpeg)

https://www.cnbeta.com/articles/science/1087215.htm 

https://www.cnet.com/news/newfound-comet-named-leonard-may-be-the-one-to-watch-in-2021/

http://astro.vanbuitenen.nl/comet/2021A1

https://groups.io/g/comets-ml/topic/analysis_light_curve_comet/81841458?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,81841458

http://astrocometas.blogspot.com/

(https://1.bp.blogspot.com/-HNrtueBsFuA/YGmPydLZfvI/AAAAAAAAC2Y/gl0oDPiYygIjDD2JInQl6sab7VfB0oAvwCLcBGAsYHQ/s1890/curva-de-luz-2021-a1.jpg)

12/21

UPDATE

http://astro.vanbuitenen.nl/comet/2021A1

金星即將與彗星近距離接觸 ,   簡單來說就是C/2021 A1 彗星的塵埃軌跡將會擦過金星。這一篇在《天文雜誌》發布的新論文，研究了流星落在金星上並在地球上可見的可能性

Akatsuki  破曉號  金星氣候衛星，或譯為黎明號 是日本宇宙航空研究開發機構的行星探測


https://tomorrowsci.com/science/%E9%87%91%E6%98%9F%E5%8D%B3%E5%B0%87%E8%88%87%E5%BD%97%E6%98%9F%E8%BF%91%E8%B7%9D%E9%9B%A2%E6%8E%A5%E8%A7%B8%EF%BC%81%E5%B0%88%E5%AE%B6%E8%A1%A8%E7%A4%BA%EF%BC%9A%E3%80%8C%E5%8F%AF%E8%83%BD%E6%9C%83/amp/

https://www.iflscience.com/space/venus-upcoming-close-encounter-with-comet-could-cause-a-visible-meteor-shower/

http://astrocometas.blogspot.com/
(https://1.bp.blogspot.com/-B_yjw3YkneI/YTXM-FehvGI/AAAAAAAAC68/JCBiUjpbSBwQYLLjtuJ9X6F_8J2WbNVygCLcBGAsYHQ/s1865/238827645_10221217871539769_1186842087780552359_n.jpg)

C/2021 A1(Leonard)將於12月成為2021年最明亮的彗星    https://www.tam.museum/astronomy/forecast_detail.php?lang=tw&id=499 



http://astro.vanbuitenen.nl/comet/2021A1

 

https://skyandtelescope.org/online-gallery/comet-c-2021-a1-leonard-at-magnitude-12/

https://skyandtelescope.org/astronomy-news/how-bright-will-comet-leonard-get/
(https://skyandtelescope.org/wp-content/uploads/Leonard-forward-scattering-angle-ICQ-Better-S2.jpg)

https://www.facebook.com/photo/?fbid=10166000187345012&set=a.241780815011

(https://scontent.ftpe8-2.fna.fbcdn.net/v/t1.6435-9/245608000_10166000187355012_361542378035534414_n.jpg?_nc_cat=103&ccb=1-5&_nc_sid=730e14&_nc_ohc=B1J545-limgAX8dXQWL&tn=WExnEL7rsh-ZaKvP&_nc_ht=scontent.ftpe8-2.fna&oh=dba69b5c2652d24a2fbdbcd16e8cbc08&oe=618C7050)

C/2021 A1(Leonard)將於12月成為2021年最明亮的彗星  

11/6 用 accord  10" DOB 看過  比  67p 暗

https://www.tam.museum/astronomy/forecast_detail.php?lang=tw&id=499


預計於2021年12月13日最接近地球且最亮，粗估屆時總亮度將達到2.4 ~4 等以上，可能會是2021年最明亮的彗星，並且有機會於天亮前以肉眼見到它的身影，若有興趣拍攝者，現在已可利用中大型望遠鏡看見它，實際經過的大略路徑請見下圖

(https://www.tam.museum/astronomy/htmlFiles/images/stellarium-008.jpeg)

看來  12/5~ 9    東邊可拍 , 仰角還可  還沒月光干擾
12/10 後 變亮  但仰角越來越低   太陽快出來 .
12/13 假設最亮   2~3

12/14  日落後西邊  可看

12/15


12/17  NGC6716  星團

12/3  M3

2021/11/25   C/2021 A1(Leonard)會   NGC 4656   NGC4627

 http://www.tam.museum/astronomy/forecast_detail.php?lang=tw&id=580

https://www.facebook.com/photo?fbid=10159563600957380&set=gm.1545745302262593

https://www.facebook.com/photo/?fbid=10159563465152380&set=gm.1545689922268131

(https://scontent.ftpe8-3.fna.fbcdn.net/v/t39.30808-6/257373353_10159563465142380_4401250267251171487_n.jpg?_nc_cat=111&ccb=1-5&_nc_sid=825194&_nc_ohc=uwBqi007kp4AX96Fbo5&tn=ofP3CwPR8fEOkQGS&_nc_ht=scontent.ftpe8-3.fna&oh=3950e39e29223768128a8a717ffb742b&oe=619AF770)

UPDATE

王朝

C/2021 A1可見時段：

1. 12/1-12/10，天文曙光前仰角>10度且無月光
2. 12/21-1/1，天文暮光終後仰角>10度且無月光
3. 1/4-5天黑後眉月與彗星距離近，50mm左右鏡頭配FF可拍下

4. 1/17後天文暮光時彗星已西沉

http://www.aerith.net/comet/catalog/2021A1/2021A1.html

https://www.cometchasing.skyhound.com/

https://www.skyatnightmagazine.com/advice/comet-c-2021-a1-leonard/

C/2021 A1 (Leonard) 可能分裂


https://www.facebook.com/photo?fbid=919533558674987&set=gm.1553640748139715  

comet C2021 A1 leonard nucleus started disintegrating in two parts

https://twitter.com/aciqra/status/1465069604489678850?s=20&fbclid=IwAR2EyPgQ3vnb5__fIZ52bISNQDAxm49LJrMKmDIcrhK6YzQ_w0k9AvLL4HM

寶傑你怎麼看

A recent image is showing 2 jets coming from the coma. This is probably not a good sign  https://twitter.com/Comet2021a1/status/1464940687561048067

https://twitter.com/aciqra/status/1465069604489678850?s=20&fbclid=IwAR1YCt_ukZ2ESiKzvSDKnjyEGx679NdF3cB0f16kOceXH3yVlltbm2frkq0

Comet C/2021 A1 (Leonard) looking a bit deflated this morning; its flattened gas coma suggests the nucleus is likely fragmenting at some level. While still brightening as seen from Earth, the absolute brightness of its dust coma has actually faded ~0.4 mag over the past week.

https://www.facebook.com/140234731687/photos/a.155712931687/10158024226451688/

(https://scontent.ftpe7-1.fna.fbcdn.net/v/t39.30808-6/261768904_10158024226446688_3428018296616708086_n.png?_nc_cat=100&ccb=1-5&_nc_sid=730e14&_nc_ohc=HE4drUHFlQIAX_zY8R8&_nc_ht=scontent.ftpe7-1.fna&oh=d46b4ab91a301676b809b961081ad9ea&oe=61AAB884)

https://cobs.si/?fbclid=IwAR1MgFowGhIQDDBeowk1XdQWtXs24YKgqpFg2unjsJhxORMoaTIjsmgalhs 

C/2021 A1 (Leonard) 在有跟沒有分裂之間  

https://www.facebook.com/photo/?fbid=4478683045582000&set=pcb.4724544650936215

美西以亞利桑那州的一支一米口徑的望遠鏡拍攝的結果，看起來沒有外傳的彗核分裂的狀況啊

FB=>  https://www.facebook.com/photo/?fbid=10161467242488065&set=gm.1554031588100631

C/2021 A1 (Leonard) ~3 hours ago with the CSS 1m telescope on Mt. Lemmon, Arizona. I shot it with short 1s exposures to get as much detail as possible of the inner coma and pseudo-nucleus

https://www.facebook.com/photo?fbid=5247547551928263&set=gm.1554206651416458



https://www.facebook.com/photo/?fbid=5119062421455347&set=pcb.1554131928090597

(https://scontent.ftpe7-2.fna.fbcdn.net/v/t39.30808-6/262732353_5119062411455348_3499241233740299241_n.jpg?_nc_cat=109&ccb=1-5&_nc_sid=b9115d&_nc_ohc=gvbXKNURKGUAX-_OsAt&_nc_ht=scontent.ftpe7-2.fna&oh=8ff5c33a2fcac5826bd7c5c9e7aa62a7&oe=61AA7CFE)

https://olhardigital.com.br/en/2021/11/29/colunistas/cometa-leonard-pode-estar-se-desintegrando/


大意  :  有人拍 彗核怪怪心型 可能分裂, 但其他望遠鏡看還好 ,   但彗髮 形狀怪怪的.   接下來再看

1.5m Kuiper telescope  https://www.facebook.com/photo?fbid=10161471243803065&set=gm.1555333544637102

https://twitter.com/comet2021a1?lang=es

https://twitter.com/cbellh471/status/1465635506696429569/photo/1

(https://pbs.twimg.com/media/FFb6odGXwAIvUKd?format=jpg&name=large)
http://astro.vanbuitenen.nl/comet/2021A1

https://astronomy.com/sitefiles/resources/image.aspx?item={E14B4725-B078-4301-B9B6-D9783DB08DB9} 

(https://astronomy.com/-/media/Images/Magazine%20Articles/2021/12/ASYSM1221_03.png?mw=1000&mh=800)

分享拍照
 
https://familystar.org.tw/index.php?option=com_smf&Itemid=45&topic=35819.new#new

12/3 M3  星團
12/15  NGC6645   散開星團  mag 8.5     M25
12/16  NGC6716  星團
12/18  VENUS    M55 

https://skyandtelescope.org/observing/celestial-objects-to-watch/comets/see-comet-leonard-at-its-best/

(https://skyandtelescope.org/wp-content/uploads/Leonard-Map-Dec-1-to-10-am-1.jpg)

(https://skyandtelescope.org/wp-content/uploads/Comet-Leonard-Dec-10-to-12-2021-821x600.jpg)

彗星有碎裂現象  ?



https://www.facebook.com/photo?fbid=4507662132684091&set=pcb.4753142038076476

https://www.facebook.com/photo?fbid=1577200179318431&set=pcb.1559979870839136

(https://scontent.ftpe7-3.fna.fbcdn.net/v/t39.30808-6/264739066_1577200169318432_6696563202898262826_n.jpg?_nc_cat=102&ccb=1-5&_nc_sid=b9115d&_nc_ohc=Wr5sNR1HlgcAX9Rkx8I&_nc_oc=AQlBKuu0JO0lRnHTAJXyoSV8vkrWyy2q6E38OQA9BKFa3p0VtJupJSalGQNTdlUBtmIlcIOHGeSl_o4WvSgW4zcy&_nc_ht=scontent.ftpe7-3.fna&oh=4d5d4516cbddc11e37479e83f90de0ee&oe=61B4D082)

https://www.facebook.com/photo/?fbid=10221265215204304&set=gm.1560190204151436

(https://scontent.ftpe7-1.fna.fbcdn.net/v/t39.30808-6/265717565_10221265215684316_4807427472896635660_n.jpg?_nc_cat=100&ccb=1-5&_nc_sid=825194&_nc_ohc=8tLgB0bJNzcAX_x7627&_nc_ht=scontent.ftpe7-1.fna&oh=f63725cc837e5a87831eed824767bd2d&oe=61B5BB46)

C/2021 A1 (Leonard)  可能 ??is fading and acting strange 

https://www.space.com/comet-leonard-fading-maybe-splitting?fbclid=IwAR27fVPUsnCbVsbsLTDILg8sKiwJ4G_ksUR2yks6gA06-jjHXY3kwzu9viU

"It's not great news. The comet should be brighter and brighter," Quanzhi Ye, an astronomer at the University of Maryland who specializes in comets, told Space.com. "If it's not getting brighter then something's wrong, but we don't know exactly what at this stage."

https://www.facebook.com/photo/?fbid=4597289043725365&set=a.103821636405484

(https://scontent.ftpe8-4.fna.fbcdn.net/v/t39.30808-6/264843009_4597289030392033_851593107914065628_n.jpg?_nc_cat=102&ccb=1-5&_nc_sid=730e14&_nc_ohc=F2wdzrv_dZwAX-pEy59&tn=mVlOeAKVWqxy6tBP&_nc_ht=scontent.ftpe8-4.fna&oh=00_AT_-YJJmfBtUZzDPZqtLiJwX5fIwrtHNgqdGQvkbN_D40w&oe=61B80ECB)

https://cobs.si/analysis2?col=comet_id&id=2209&start_date=2021/01/01%2000:00&end_date=2022/03/31%2000:00&plot_type=0&perihelion=1&fit_curve=1&obs_type=3


http://astro.vanbuitenen.nl/comet/2021A1

https://www.cnbeta.com/articles/science/1213903.htm  这张真实的彩色图片显示了Leonard彗星在2021年12月7日上午流经天空的情景，其由ESA的近地天体协调中心(NEOCC)拍摄。

12/18  CLOSE VENUS

12/17  NGC6716  星團 

Comet watch 說m1變2.6

https://www.facebook.com/photo/?fbid=4740335746048687&set=gm.1564719780365145

Comet C/2021 A1 (Leonard) has brightened as seen from Earth   

https://s3-us-west-1.amazonaws.com/groupsioattachments/40951/87741747/1954/2?AWSAccessKeyId=AKIAJECNKOVMCCU3ATNQ&Expires=1639572091&Signature=Vs%2F5dRofw4HYeiAd4QvkOo9s%2F6Y%3D&response-content-disposition=inline%3B+filename%3D%222021A1_20211215_0128_molason.jpg%22


Those who suggested that the comet might brighten as the comet's tails and coma aligned geometrically as seen here on Earth evidently were correct. Astrometrica and my own methods of magnitude calculation both agree that on the evening of 2021 December 14 the comet was magnitude 3.2 from images taken a few degrees above the horizon in waning twilight skies. Cheers, Mike.

https://spaceweathergallery.com/indiv_upload.php?upload_id=180453

http://astro.vanbuitenen.nl/comet/2021A1

https://www.facebook.com/photo/?fbid=10225037007687861&set=gm.1565128526990937

(https://scontent.ftpe8-1.fna.fbcdn.net/v/t39.30808-6/267397095_10225037007647860_3336890460627975984_n.jpg?_nc_cat=108&ccb=1-5&_nc_sid=825194&_nc_ohc=yWHpyTKQhU8AX_Xw5EY&_nc_ht=scontent.ftpe8-1.fna&oh=00_AT9B6VI4Ws3JLYRBKwGYQfKws1A9oQggpz-xov6J78zzxQ&oe=61BF834F)

上面這張照片，這顆彗星有到4.0-4.5等亮度了。

https://www.cnbeta.com/articles/science/1215405.htm 


金星上的流星雨？

Leonard彗星在12月12日（美国时间）最接近地球，此时它离地球仍有2100多万英里，约是地球到月球距离的88倍。目前可以在晚间天空的低处发现这颗彗星，也就是在日落之后。

12月17日，这颗彗星预计将非常接近金星，Leonard称之为宇宙中的一次亲密接触。“存在一个很小的机会，即金星将通过足够接近彗星的路径，它可能在其大气中拾取一些尘粒并在我们的邻星上产生流星雨。”

Leonard指出，有时被称为“黄昏之星”的金星目前在日落前后在西南方的天空中非常显眼并且可能成为一个有用的路标以帮助天空观察者定位彗星。“从12月13日开始，这颗彗星将在日落后出现在地平线上，非常低。从现在起到圣诞节前后，它将掠过西南偏西的地平线。它离地平线如此之近的事实使得这颗彗星的观测有点挑战性。”

尽管如此，Leonard还是鼓励人们去尝试一下，他解释称，观察者可能会从一种叫做前向散射的效应中受益。当它接近太阳时，彗星的尾巴和“彗星”--一团尘埃和气体--可能会从后面散射阳光并有可能极大地提高彗星的亮度。

“我觉得即使是普通的观察者也会有一些东西可以看到。给自己找一个黑暗的天空，拥有良好的地平线视野，带上双筒望远镜，我想你可能会得到回报，”Leonard说道


https://scitechdaily.com/how-to-see-comet-leonard-before-its-gone-forever-according-to-the-researcher-who-discovered-it/

Still, Leonard encourages people to give it a try, explaining that observers may benefit from an effect called forward scattering: As it comes closer to the sun, the comet’s tail and “coma” – a cloud of dust and gas – may scatter the sunlight from behind, potentially dramatically enhancing the comet’s brightness.


effect called forward scattering

https://en.wikipedia.org/wiki/Forward_scatter

變暗    昨天跑去拍  
那時應該還有  3.x 等

https://familystar.org.tw/index.php?option=com_smf&Itemid=45&topic=35819.new#new


看來是  變暗

DEC 20

 C/2021 A1 (Leonard)   再次變亮  

https://cometsky.tistory.com/1307?category=735305



http://astro.vanbuitenen.nl/comet/2021A1





now coming in that C/2021 A1 LEONARD has exploded in brightness to magnitude 2 and is sporting a thicker tail


https://www.facebook.com/photo/?fbid=4387772238016481&set=gm.1568424013328055

Comet Leonard after its outburst on December 20, 2021.
Place: Priseaca - Targoviste, Romania, Bortle 4

https://twitter.com/cosmos4u/status/1472897129999917058  

https://twitter.com/vivstoitsis/status/1473059747981004800/photo/1



Tonight, comet C/2021 A1 Leonard is seen in outburst.
It was easily visible naked eye at an altitude of 12 degrees on 2021 Dec 20.47UT. m1=2.9, corrected for extinction. strongly condensed.
My observation in 8x40mm binoculars 2 nights ago, on 2021 Dec 18.47UT, was m1=4.2

https://twitter.com/MichaelMattiazz/status/1472919826859380737/photo/1

LIVE  C/2021 A1
https://www.youtube.com/watch?v=y66eUXg8cbM

https://www.youtube.com/watch?v=Ml7T5GH-FkI

國外同好 拍 真的漂亮

https://www.facebook.com/photo/?fbid=1285821135268049&set=pcb.1569089299928193


https://www.facebook.com/photo/?fbid=4636075773107265&set=gm.1568847889952334

(https://scontent.ftpe8-3.fna.fbcdn.net/v/t39.30808-6/269728884_4636075706440605_1396473190025589514_n.jpg?_nc_cat=111&ccb=1-5&_nc_sid=8631f5&_nc_ohc=wPHtqL0zui4AX8-ltsD&_nc_ht=scontent.ftpe8-3.fna&oh=00_AT9K0ODdvhsQxKwFAwCDJ1r7qJiS8GoSFyh-NEJmkjekSw&oe=61C804C7)

恩....離子尾和彗尾噴流都混在一起....基本上算是還是很稀薄..北半球觀測條件逐漸不行了.變成是南半球的天下了...

YES

南半球 賺到  不過  北部天氣差  

算拉

 8"/f-3 Veloce
  => RH200  嗎??



FROM   Michael Jäger


C/2021 A1 Leonard 2021 dec 21 UT 19.19 RGB 270/270/270sec 8"/f-3 Veloce QHY600 photos provided by Skygems.nambia Lukas Demetz,
long exposure times are useless, the comet's tail is moving rapidly,


(https://spaceweathergallery.com/submissions/pics/m/Michael-Jaeger-2021A120211222rgbweb_1640131877.jpg)

呵呵呵....現在就看看西南部的鄉親看看在於12月底前是否可以觀測或拍的到..這麼近的彗星,彗核部分看起還很原始! 尾巴的噴流流動很快! 拍的時間可能無法過長.........台中以北....吃完湯圓準備過年了.

看來南部  今天 有機會   

北部  要看  明後天  吧

https://www.youtube.com/watch?v=Qj2JCBoQXqg

Comet Leonard, Venus & Mercury captured by Solar Orbiter

https://www.youtube.com/watch?v=thJ99EzSkP8

https://www.youtube.com/watch?v=gRAG_0j0CSg

https://www.youtube.com/watch?v=5VcY1KLXnQw

https://weibo.com/1029143002/L7dk29teL?layerid=4717195102257343


https://cometsky.tistory.com/1308

(https://blog.kakaocdn.net/dn/k4Tcs/btroDvbQ5zW/RkzwyYLoygp0rCbnn1rLak/img.jpg)

https://www.universetoday.com/153789/two-spacecraft-view-comet-leonard/

https://www.youtube.com/watch?v=fo6KDQXYlSs  
臺北天文館福壽山農場星空直播

https://www.cnbeta.com/articles/science/1218379.htm 

https://skyandtelescope.org/astronomy-news/comet-leonard-a-gift-at-christmastime/

(https://skyandtelescope.org/wp-content/uploads/Leonard-Dec-24-Michael-Jaeger-and-Lukas-Demetz-V2.jpg)

Braided flows of gas and dust stream from the head of Comet Leonard in a photo taken with an 8-inch telescope and QHY600 camera on December 24, 2021. Compare this image to the one below from two nights earlier.
Michael Jäger and Lukas Demetz

(https://skyandtelescope.org/wp-content/uploads/Leonard-Dallas-33N-Dec-25-to-Jan-3-832x600.jpg)

上  APOD
https://apod.nasa.gov/apod/ap211227.html?fbclid=IwAR1_y10mU4XwXJtNthKc88bVUEjidBpUO8WF8tWrhTlVh2tJJP8yB9wA5KQ

(https://apod.nasa.gov/apod/image/2112/CometJwst_Matipon_1080.jpg)

https://www.cnbeta.com/articles/science/1219463.htm 
https://www.cnet.com/how-to/see-comet-leonard-and-its-rare-disconnecting-tail-as-it-races-toward-the-sun/

C/2021 A1 (Leonard)    斷尾 

他在spaceweather.com上写道：“彗尾的一部分已经被掐断，被太阳风带走了。”

Phillips 说，由太阳耀斑或来自太阳的日冕物质抛射引起的空间天气可能导致了这种奇怪的景象。“即使是普通的太阳风流撞击彗星，也会在彗星的电离尾部引起磁力重联，有时会把它们完全扯下来。”

美国宇航局（NASA）2007年曾在Encke彗星上捕捉到了这种现象。


也有可能额外的内部尾巴只是彗星核心的碎片爆发的产物，表明整个彗星可能正在解体。要知道一颗彗星内部到底发生了什么，总是很困难。

大量来自观察者的报告说，Leonard在肉眼或双筒望远镜下是可见的，

https://weibo.com/1029143002/L7dk29teL?layerid=4717195102257343 

COBS 12月1日-·12月27日的目视数据每天平均值变化曲线。 ​​​
https://weibo.com/u/1029143002?layerid=4719308082775747




https://weibo.com/u/1029143002?layerid=4718768258813759

伦纳德的碎片？
Bill Williams 12月25日在佛罗里达州基夫兰天文村拍摄

(https://wx2.sinaimg.cn/mw2000/3d5779dagy1gxrk5r61g4j20u015d4bw.jpg)

http://www.aerith.net/comet/catalog/2021A1/2021A1.html

倫納德彗星的尾巴有多長  https://www.facebook.com/photo?fbid=10159888521580762&set=pcb.10159888522300762

它有 60 度長。” 從這個角度來看，倫納德彗星的尾巴是北斗七星的兩倍多，是滿月的 120 倍。 “這令人印象深刻，”加斯帕里說。

Leonard after new outburst   

https://www.facebook.com/APOD.Sky/photos/a.4214632848640902/4353823244721861 
A broken piece of Comet Leonard
Credit: Magnus Gålfalk
(https://scontent.ftpe7-3.fna.fbcdn.net/v/t39.30808-6/271812834_4353823231388529_5953714511744091310_n.jpg?_nc_cat=103&ccb=1-5&_nc_sid=0debeb&_nc_ohc=FNpDL82HJHIAX8QolTP&_nc_ht=scontent.ftpe7-3.fna&oh=00_AT-zUinky8bnKXQlzzH3KOmwXeeV2K2MSYd1trwBIgYxyg&oe=61E7AA8F)

https://www.gizmodo.com.au/2022/03/rip-comet-leonard-a-bright-visitor-in-a-dark-time/ 

nucleus disintegrated or evaporated