三日月、12P 彗星 、M31 仙女座星系

(3/8, 3/12)

3/12

Crescent Moon, Comet 12P, and the Andromeda Galaxy

星期二傍晚 (3/12)天氣很好（比上個星期好），於是下班後再次爬山大屯山主峰拍攝，從約七點拍到七點五十分左右，因為低海拔受霧霾影響透明度稍差，所以我挑掉了仰角五度以下的影像，總共疊合了30分鐘。

當晚的三日月也很美，我也用FA31拍攝了包含三日月的影像，花了些時間把它們接起來。

The weather was good on Tuesday evening (better than last week), so I went hiking up Datun Mountain Main Peak again after work to take pictures. I shot from around 7:00 PM to 7:50 PM. The transparency was slightly affected by haze at low altitudes, so I discarded images with an elevation angle of less than five degrees. I stacked a total of 30 minutes of images.

The crescent moon was also beautiful on Tuesday night. I also used the FA31 to take pictures of the crescent moon. It took me some time to stitch them together. for the star-Landscpae ,   I used Starnet to separate the stars and then enhanced the blending to make it look more natural.

Pentax K3II

FA31 , 6 frames for stars and landscape

FA77 ＠F4 ISO2000, ASTROTRACER 20sec x90 frames for comet and m31

SiriL, Starnet, Photoshop

在疊合時我先挑掉了一些彗星已降到接近仰角五度的影像（受透明度與消光影響已非常模糊），僅取共三十分鐘的總曝光時間。

我單張只曝光20秒，除了避免受到山腳的台北市光害影響而過曝，也有減少追蹤誤差的影響的效果，我使用排程快門線來拍攝彗星與M31，設定拍攝十五張，每拍攝完十五張後我便會重新調整構圖，然後再繼續拍攝十五張，如此重複。

因為在天文暮光中開始拍攝，影像受暮光的影響隨之變化，而當天文暮光結束後，隨著彗星的仰角降低，影像則受到的城市光害、大氣消光以及霧霾等影響漸增，所以在SiriL中疊合的時候我設定以每張影像的星星數作為權重。

I only exposed each image for 20 seconds. This was not only to avoid overexposure from the light pollution of Taipei City at the foot of the mountain, but also to reduce the effects of tracking errors. I used a scheduled shutter release to shoot the comet and M31. I set it to take 15 images. After each set of 15 images, I would recompose the shot and then continue shooting another 15 images. I repeated this process.

Since the imaging started during astronomical dusk (twilight), the images were affected by the twilight, which changed accordingly. After astronomical dusk ended, the images were increasingly affected by urban light pollution, atmospheric extinction, and haze as the comet's altitude decreased. Therefore, when stacking in SiriL, I set the weight to be the number of stars in each image.

(彗星亮度約六等， SOT=38°, Nautical dusk end= 6:51 PM, Astronomic dusk end=7:17 PM)

冬季銀河、馬卡鏈

2/14

初五

台北天氣非常好，於是上山開電、看星星。剛好又遇到文正兄帶著他的eVscope2也上來。

這陣子都帶Pentax MS-3單軸赤道儀（改赤經加導星埠），使用MGENII的內建漂移法修正極軸功能對極，由於已經熟悉了，所以這次很快就修到顯示誤差在1.5’，750mm 焦長單軸導星單張3分鐘仍相當圓，符合預期，拍馬卡鏈曝35張只有三張離群較高，平均roundness約在0.91算是很優，不過我只帶了三波長窄頻NB1濾鏡，所以我的全光譜改機只能先拍一下窄頻，改天再拍正常L濾鏡。

遠方小觀音山電台最近出現的一盞白光廣場燈大約八點就關閉了，但月亮要到接近午夜才下山，所以可以一邊吃著泡麵先欣賞月光，在月亮下山後也用 ASTROTRACER  拍了幾張星景跟冬季銀河（使用未改機K3II，下次再找機會用改機拍）。

這晚鞍部的暗空狀況算是正常的良好值 ，午夜後天空就進入了最佳的狀況（午夜SQ20.1）。

不過因為不想要操勞，所以我們約兩點多都下山回家睡覺了，下山前遇到一位在學學生才剛上來準備要爬上大屯山去拍日出銀河。

The weather in Taipei was very good on the fifth day of the Lunar New Year, so I went up the mountain to 開電（It symbolizes the first time in a year that you are using your work tools） and go stargazing. I happened to meet my friend Wen Zheng who was also going up with his eVscope2.

I have been using the Pentax MS-3 single-axis equatorial mount (modified with a RA guiding port) recently. I used the built-in drift method of MGENII to correct the polar axis. Since I am already familiar with it, I quickly adjusted it to a display error of 1.5'. The 750mm focal length  single shot is still quite round at 3 minutes, which meets expectations. and the average roundness was about 0.91, which is considered very good. However, I only brought  NB1 filters, so my full-spectrum modified camera K5 can only shoot narrowband first, and I will shoot normal L filters another day.

The white floodlight at the 小觀音Mountain Radio Station in the distance was turned off at around 8 o'clock, but the moon would not set until close to midnight. So I could eat instant noodles while enjoying the moonlight, and after the moon set, I used the ASTROTRACER to take a few pictures of the starLandscape and the winter Milky Way (using the unmodified K3II, I will find another opportunity to use the modified camera to shoot next time).

The dark sky conditions at the saddle this night were considered normal and good. The sky was at its best after midnight (midnight SQ20.1).

However, we didn't want to overwork ourselves, so we all went down the mountain  at around 2:30. Before going down the mountain, we met a student who was just going up to climb 大屯山主峰 to shoot the sunrise and the Milky Way.

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Pentax K3II, DA10-17

winter milky way of 大屯鞍部  was combined with 6 frames, and each frame was stacked with 10 sub frames (40sec each sub fame)

registar, Potoshop

62P彗星、M45七姊妹星團、冬季星空/ 梅杜莎蛇妖星雲

1/14~15


星期天傍晚看天氣還OK，晚上吃完晚餐便整理一下器材就上山。到停車場時看到eVscope 2跟S50同時出現就知道星友文正早已經上來了。


這一晚仍然是如上回上來操作MGENII的飄移法修正極軸並作單軸導星。見到了燦爛星空，大約凌晨近兩點時便滿足地收拾東西回家睡覺了。

Pentax K3II, DA 10-17mm@10, ASTROTRACER 50sec

上半夜如預報，時有薄雲飄過，濕度頗高。不過近午夜天空便全開了，透明度很不錯，因此暗度也達到了SQ20的平均水準之上。

先繼續曝了些女巫頭，然後拍了一下正在室女座的62P彗星 （2minx8)，以及曝了一小時的M45（3minx20。打算要累積至少共六小時），對極與導星都算是很穩定。

Pentax 75SDHF,  smc 0.72x reducer, L-3 filter, Pentax MS-3赤道儀(改), Pentax K5(全光譜)

使用 MGENII 的飄移法修正Pentax MS-3 極軸並作單軸導星，隨意曝了 M45七姊妹 共 1小時（單張3分鐘。目標希望曝5個小時以上。）

20張裡面若龜毛一點踢掉兩張離群稍微遠一點點的 0.83（放到1:1看其實還OK)，平均的正圓度也差不多是在0.89~0.9，跟上回差不多，使用MGENII的來飄移修極軸目前算是頗穩定。

62P彗星，2minx10 曝光20分鐘