Deep Sky

【Date】2025/05/02

【Pic Info】
去年拿到小紅貓望遠鏡後，第一個後製的天體就是 M51 渦狀星系。只不過當時第一次拍這麼小的天體，沒有經驗，拍不好也沒有修好，當時的作品真是慘不忍睹。過了一年之後補考 M51，這次收到不錯的效果，但 M51 實在太小了，有些細節拍不出來，是不是可以入手中長焦的鏡子呢哈哈！

再次介紹 M51 吧！位於獵犬座的 M51，距離地球 2,300 萬光年。由於重力的作用，兩個星系在接近的過程互相拉扯，M51 就是處於這樣緩慢拉扯變形的途中，最終將互相碰撞、合併。

另外 M51 赤緯（註 1）為 +47°，對於北緯 43 度以上的觀測者來說，M51 是拱極星（永不落下）；M51 在整個北半球都達到很高的高度，從 11 月清晨到 5 月底都可觀測。

[註一] 赤緯：類似地球經緯度的概念，是經緯線在天球上的投影。簡單來說，舉一手與北極星成一直線，舉另一手與之成直角，北極星那手就是指向赤緯 +90°，天南極就是赤尾 -90°。

[M51 Whirlpool Galaxy]

After acquiring the RedCat telescope last year, the very first celestial object I post-processed was the M51 Whirlpool Galaxy. However, it was my first time capturing such a small target, and due to lack of experience, both the imaging and the processing fell short — frankly, the result was quite dreadful. One year later, I gave M51 a “retest,” and this time achieved a much better outcome. Still, M51 is truly small, and some details remain out of reach. Perhaps it’s time to consider investing in a medium-to-long focal length telescope — haha!

Let’s reintroduce M51!

Located in the constellation Canes Venatici, M51 is approximately 23 million light-years away from Earth. Due to gravitational interactions, the two galaxies involved are pulling and distorting each other as they slowly draw closer, with M51 currently in the midst of this gradual tidal distortion. Eventually, they will collide and merge into a single system.

Additionally, M51 has a declination (Note 1) of +47°, which makes it a circumpolar object (never setting) for observers located above 43° north latitude. Across the entire Northern Hemisphere, M51 reaches a high altitude in the sky and is observable from early November pre-dawn hours through the end of May.

[Note 1] Declination: Similar to Earth’s latitude-longitude system, declination refers to the projection of these coordinate lines onto the celestial sphere. Simply put, if you point one hand straight toward Polaris (the North Star) and the other at a right angle, the hand pointing to Polaris indicates declination +90°, while the celestial south pole lies at declination –90°.

———

• iOptron GEM28

• William Optics REDCAT 51 WIFD

• ZWO ASI 2600MC Duo

• ZWO ASIAIR Mini

• Antlia RGB ULTRA

• 2025/05/02

• Dark: 48

• flat: 48

• light: 48 * 300s (total 4 hr)

• bias: 48

• ★★ PixInsight processing

  • Weigthed Batch Processing

  • DynamicBackgroundExtraction

  • AutomaticBackgroundExtractor

  • SCNR

  • ImageSolver

  • SpectrophotometricColorCalibration

  • NoiseXTerminator

  • StarNet

  • HistogramTransformation

  • ColorSaturation

  • PixMath

• Photoshop crop & add logo

【Date】2025/02/28

【Pic Info】
以為只有人類有戰爭嗎？當然不是囉！在夜晚的天空每天上演著星系拉鋸戰，今天的主角就是大熊座的 M81 波德星系和 M82 雪茄星系。

螺旋狀的是 M81 波德星系，是典型的 Sb 型螺旋星系（註一），與銀河系不同的是，銀河系屬於棒旋星系，通常愈成熟的星系，會愈趨近於棒旋結構。

另外一個不規則的星系是 M82 雪茄星系，其亮度約為銀河系的五倍。因猛暴恆星形成區及劇烈的星雲碰撞，恆星風因而將星系中的氫氣游離並向星系外吹送，因而在星系盤面上下形成扇狀的纖維狀雲氣結構，也就是看起來紅色部分。然而正受到鄰居 M81 的影響。由引力造成的潮汐力使這個星系變形，這個過程大約開始於一億年前，在接下來的數十億年之中，它們持續重力互擾，最後會合併成單一個大星系。

其實畫面中還包含 NGC 2976 和 NGC 3077，後者也參與 M81 星系團的拉鋸戰中，如第二張圖，但受限於望遠鏡的口徑和焦距，細節沒有很清楚，是不是要入手中長焦段的望遠鏡呢 XDDDDD

註一：螺旋臂依密度約可分為 Sa、Sb、Sc 型，密度 Sa > Sb > Sc。

[Galactic Wars – M81 & M82]

Do you think only humans wage wars? Of course not! In the night sky, galactic tug-of-war battles unfold every day. Today's protagonists are M81 Bode's Galaxy and M82 Cigar Galaxy in the constellation Ursa Major.

The spiral-shaped galaxy is M81, also known as Bode's Galaxy — a typical Sb-type spiral galaxy (Note 1). Unlike the Milky Way, which is a barred spiral galaxy, more mature galaxies tend to evolve into barred spiral structures.

The irregular galaxy next to it is M82, the Cigar Galaxy, which is about five times brighter than the Milky Way. Due to its violent star-forming regions and intense nebular collisions, stellar winds ionize hydrogen gas and blow it out of the galaxy, forming fan-shaped, filamentary clouds above and below the galactic plane — visible as the red regions in the image. However, this galaxy is under the gravitational influence of its neighbor, M81. Tidal forces caused by gravity are distorting M82, a process that began about 100 million years ago. Over the next few billion years, the two galaxies will continue their gravitational dance, eventually merging into a single massive galaxy.

The image also includes NGC 2976 and NGC 3077, with the latter also participating in the M81 galaxy group's cosmic tug-of-war (as shown in the second image). However, due to the telescope's aperture and focal length limitations, the details are not very clear. Maybe it's time to get a mid-to-long focal length telescope? XDDDDD

Note 1: Spiral galaxies are classified by the tightness of their spiral arms into Sa, Sb, and Sc types, where the density follows the order: Sa > Sb > Sc.

———

• iOptron GEM28

• William Optics REDCAT 51 WIFD

• ZWO ASI 2600MC Duo

• ZWO ASIAIR Mini

• Antlia RGB ULTRA

• 2025/02/28

• Dark: 30

• flat: 60

• light: 60 * 300s (total 5 hr)

• bias: 60

• ★★ PixInsight processing

  • Weigthed Batch Processing

  • DynamicBackgroundExtraction

  • AutomaticBackgroundExtractor

  • SCNR

  • ImageSolver

  • PhotometricColorCalibration

  • NoiseXTerminator

  • StarNet

  • HistogramTransformation

  • ColorSaturation

  • PixMath

• Photoshop crop & add logo

【Date】2025/01/30

【Pic Info】
連假最後一晚的好天氣，就獻給超暗、超難拍的義大利麵星雲吧！

在電子星圖上，義大利麵星雲非常黯淡，只有一絲絲很淡的輪廓，但卻能激起我的挑戰欲。從 18:30 開始拍攝，此時仰角已到 45°，只不過到 02:00 前，約有 2 小時都有雲層，拍出來的照片不乾淨，因此實際上曝光時間只有 4 小時。

而在後製時，使用 HOO 色板，加強氧的譜線，讓青藍色雲氣較為明顯。參考其他同好的作品，曝光時間各個都 10 小時以上（至少曝光兩晚），真不愧是大魔王，我這曝光四小時能成這樣，已經很滿足了 XDDDD 等下一個冬季繼續挑戰吧～

義大利麵星雲，西梅茲 147（Simeis 147），又被稱為 Sh2-240，是一個巨大的超新星殘骸，249mm APS-C 的鏡頭與感光元件呈現下，基本上該星雲將近滿版。如用更直白的說法，雲氣總和差不多為六個滿月的天區，實際大小大約 150 光年，若以最快的人造太空探測器（如「帕克太陽探測器」，時速約 70 萬公里）來看，它需要超過 200 萬年才能橫跨整個星雲。

The last night of the vacation blessed us with great weather, so I dedicated it to capturing the ultra-dim and ultra-difficult Spaghetti Nebula!

On digital star charts, the Spaghetti Nebula appears extremely faint, with only the slightest wisps of structure visible—but that only fueled my determination to take on the challenge. I started shooting at 18:30, with the nebula already at a 45° altitude. However, for about two hours before 02:00, clouds rolled in, making some of the frames unusable. As a result, the actual exposure time was only four hours.

During post-processing, I used the HOO palette, enhancing the oxygen emission lines to make the cyan-blue filaments stand out more. Looking at works from fellow astrophotographers, most of them had at least 10 hours of exposure (spread over multiple nights). This nebula is truly a final boss-level target! Given that I only managed four hours, I’m already quite satisfied with the result. I’ll definitely come back for another attempt next winter!

The Spaghetti Nebula, Simeis 147 (Sh2-240), is a massive supernova remnant. Under my 249mm APS-C lens and sensor, it nearly fills the entire frame. To put it in simpler terms, the nebula spans an area roughly six times the size of a full moon in the night sky. In reality, its actual size is around 150 light-years across. If the fastest human-made space probe—like the Parker Solar Probe, which travels at about 700,000 km/h—were to cross this nebula, it would take over 2 million years to do so!

———

• iOptron GEM28

• William Optics REDCAT 51 WIFD

• ZWO ASI 2600MC Duo

• ZWO ASIAIR Mini

• Antlia RGB ULTRA

• 2025/01/30

• Dark: 24

• flat: 48

• light: 48 * 300s (total 4 hr)

• bias: 48

• ★★ PixInsight processing

  • Weigthed Batch Processing

  • DynamicBackgroundExtraction

  • AutomaticBackgroundExtractor

  • SCNR

  • ImageSolver

  • PhotometricColorCalibration

  • NoiseXTerminator

  • StarNet

  • HistogramTransformation

  • Narrowband Normalization

  • ColorSaturation

  • PixMath

• Photoshop crop & add logo

【Date】2025/01/29

【Pic Info】
今天的標的是位於御夫座的火焰星雲（IC405）與蝌蚪星雲（IC410）。畫面中左上即是蝌蚪星雲，中間是火焰星雲。

其中火焰星雲是反射星雲與發射星雲的合體。藍色部分是御夫座 AE，由於極為熾熱，所以輻射出很藍的高能量星光，但此時也會把周圍雲氣裡的電子給撞飛，當質子再捕獲電子時，通常會發出紅光輻射（此圖以橙色呈現）。因為上述的交互作用，所以火焰星雲包含反射星雲與發射星雲的特性。

蝌蚪星雲由中心的年輕星團 NGC 1893 的輻射驅動，它以兩條類似蝌蚪的塵埃結構聞名。這是一個極具科學價值與美感的深空天體，吸引著業餘天文攝影愛好者與專業天文學家的關注。

另外這次在後製時，使用 PixInsight 的外掛 Package「Narrowband Normalization」。其實原圖兩個星雲中心是亮橘色，使用窄頻 HOO 色板，讓中心凸顯藍色反射的特性。也因為這次的後製，更深入研究 SHO、HOO、Hα-OIII、SII-Hα 的差異。尤其是 SHO，也就是哈伯色板，等今年夏天拍老鷹星雲看能不能調出創生之柱 XDDDD

* 註一 * 御夫座 AE：是一顆高速移動的流浪恆星，可能來自獵戶座大星雲區域，數百萬年前因超新星爆炸或重力相互作用被拋出。雖然它現在位於 IC 405 內，但它其實只是「路過」，並非形成該星雲的起源。

The Flaming Star Nebula is a combination of a reflection nebula and an emission nebula. The blue region is illuminated by AE Aurigae, an extremely hot star that emits high-energy blue starlight. This intense radiation ionizes the surrounding gas, knocking electrons off the atoms. When protons recapture these electrons, they typically emit red light, which appears orange in this image. Due to these interactions, the Flaming Star Nebula exhibits both reflection and emission nebula characteristics.

The Tadpole Nebula is driven by the radiation from the young star cluster NGC 1893 at its core. It is famous for its two elongated dust structures resembling tadpoles. This deep-sky object is not only scientifically valuable but also visually stunning, attracting the attention of both amateur astrophotographers and professional astronomers.

For post-processing, I used the PixInsight plugin ”Narrowband Normalization.“ In the original image, the centers of both nebulae appeared bright orange. By using the narrowband HOO palette, I highlighted the blue reflection features in the core. This process also led me to further explore the differences between SHO, HOO, Hα-OIII, and SII-Hα color mappings. In particular, I focused on the SHO palette, also known as the Hubble Palette—looking forward to this summer to see if I can bring out the Pillars of Creation when capturing the Eagle Nebula!

———

• iOptron GEM28

• William Optics REDCAT 51 WIFD

• ZWO ASI 2600MC Duo

• ZWO ASIAIR Mini

• Antlia RGB ULTRA

• 2025/01/29

• Dark: 24

• flat: 48

• light: 48 * 300s (total 4 hr)

• bias: 48

• ★★ PixInsight processing

  • Weigthed Batch Processing

  • DynamicBackgroundExtraction

  • AutomaticBackgroundExtractor

  • SCNR

  • ImageSolver

  • PhotometricColorCalibration

  • NoiseXTerminator

  • StarNet

  • HistogramTransformation

  • Narrowband Normalization

  • ColorSaturation

  • PixMath

• Photoshop crop & add logo

【Date】2025/01/28

【Pic Info】
很久以前就想挑戰水母星雲，但這片星雲太暗了，沒改的單眼根本拍不出來，於是趁著好天氣，新春第二彈就獻給水母囉！

水母星雲跟昨天拍的玫瑰星雲不一樣，是銀河系內的超新星殘骸，在光學相機下，能拍到是殘骸的外殼，在 X 輻射望遠鏡中，中心是一顆中子星。推測前身恆星壽命約 3,000 萬年（太陽現年 47 億歲），在大質量恆星生命末期，氫、氦核融合反應結束後，產生的鐵無法再做為核融合能量來源，此時自身的能量無法抗衡引力，轉而電子跑到以最低能階抵抗引力（俗稱電子簡併狀態），快速的收縮產生內爆，並將恆星物質爆發到星際空間。但這個階段對於大質量恆星來說，還是不足以抵抗引力塌陷，電子被壓入原子核，呈現中子簡併狀態再進一步防止引力塌陷，變成中子星。

我們現在生活的一切，都是由這些大質量恆星超新星爆發後產生的。我們身上配戴的，都是宇宙的歷史，曾經璀璨耀眼的光芒。

I’ve wanted to capture the Jellyfish Nebula for a long time, but it‘s too faint to be photographed with an unmodified DSLR. Taking advantage of the clear skies, I finally gave it a try—this is my second astrophoto of the Lunar New Year, dedicated to the Jellyfish!

Unlike the Rosette Nebula I photographed yesterday, the Jellyfish Nebula is a “supernova remnant” within the Milky Way. In optical images, we can see the remnant’s outer shell, while in X-ray images, a neutron star sits at its core. Scientists estimate that the progenitor star had a lifespan of about “30 million years” (for comparison, our Sun is 4.7 billion years old).

At the end of a massive star’s life, hydrogen and helium fusion reactions cease, and iron forms in its core. Since iron can no longer serve as a source of fusion energy, the star loses its ability to counteract gravitational collapse. The electrons then move to their lowest possible energy states to resist gravity, a condition known as “electron degeneracy”. This rapid contraction triggers an implosion, ejecting stellar material into interstellar space in a dramatic explosion. However, for a star of such great mass, even electron degeneracy is not enough to stop further collapse. Electrons are forced into atomic nuclei, forming neutron degeneracy, which finally stabilizes the core—leaving behind a neutron star.

Everything we know and experience today was created from the remnants of these massive stellar explosions. The elements we wear, the materials that shape our world—all are part of the universe’s long history, once shining brilliantly in the cosmos.

———

• iOptron GEM28

• William Optics REDCAT 51 WIFD

• ZWO ASI 2600MC Duo

• ZWO ASIAIR Mini

• Antlia RGB ULTRA

• 2025/01/28

• Dark: 30

• flat: 60

• light: 60 * 300s (total 5 hr)

• bias: 60

• ★★ PixInsight processing

  • Weigthed Batch Processing

  • DynamicBackgroundExtraction

  • AutomaticBackgroundExtractor

  • SCNR

  • ImageSolver

  • PhotometricColorCalibration

  • NoiseXTerminator

  • StarNet

  • HistogramTransformation

  • ColorSaturation

  • PixMath

• Photoshop crop & add logo

【Date】2025/01/27

【Pic Info】
若要論冬季最浪漫的深空天體，莫屬玫瑰星雲了。紅色雲氣如豔紅花瓣，包圍中間的亮星，宛如一朵綻放在冬季夜空中的玫瑰，為這片星空增添一絲浪漫氣息。

小年夜晚上開始，寒流高壓南下，下沉氣流帶來的晴朗天氣，就算只有十度低溫還是要把握機會，規劃一系列的冬季深空。

第一晚的玫瑰星雲位於麒麟座，距離地球約 5,000 光年，直徑約 130 光年的發射星雲。原本這片星雲非常黯淡，是因為中間年輕恆星的輻射激發原子，因此才能看到星雲。

然而玫瑰星雲並非肉眼能見，事實上紅色雲氣僅能用照相的方式紀錄，但它仰角高，位置非常好找，只要花些時間栽培，玫瑰星雲猶如愛情般，愈久愈艷，歷久彌新。

When it comes to the most romantic deep-sky object of winter, it has to be the Rosette Nebula. Its crimson clouds resemble vibrant red petals, surrounding the bright stars at its center, like a rose blooming in the winter night sky, adding a touch of romance to the heavens.

Starting on the evening before Lunar New Year’s Eve, a cold front with high pressure will descend southward, bringing clear skies due to sinking air currents. Even with temperatures as low as 10°C, this is a perfect opportunity to plan a series of winter deep-sky observations.

On the first night, the Rosette Nebula, located in the constellation Monoceros, lies about 5,000 light-years from Earth and spans approximately 130 light-years in diameter. Originally, this nebula is quite faint, but it becomes visible due to the radiation from the young stars at its center, which excites the surrounding atoms.

However, the Rosette Nebula cannot be seen with the naked eye. Its red clouds can only be captured through photography. Despite this, its high altitude in the sky makes it easy to locate. With patience and dedication, the Rosette Nebula, much like love, becomes more vivid and enduring over time.

———

• iOptron GEM28

• William Optics REDCAT 51 WIFD

• ZWO ASI 2600MC Duo

• ZWO ASIAIR Mini

• Antlia RGB ULTRA

• 2025/01/27

• Dark: 30

• flat: 60

• light: 60 * 300s (total 5 hr)

• bias: 60

• ★★ PixInsight processing

  • Weigthed Batch Processing

  • DynamicBackgroundExtraction

  • AutomaticBackgroundExtractor

  • SCNR

  • ImageSolver

  • PhotometricColorCalibration

  • NoiseXTerminator

  • StarNet

  • HistogramTransformation

  • ColorSaturation

  • PixMath

• Photoshop crop & add logo

【Date】2025/01/04

【Pic Info】
台灣北部的天氣實在太糟糕，等了一個多月才盼到這麼晴朗的夜晚，就算感冒也要衝一波啦！只不過新竹風太大，好幾次比較大的陣風讓導星失效。本來要拍四個小時，只不過重新校正導星花比較多時間，最終拍三個多小時結束 XD

這次拍攝的目標是 IC 434，位於獵戶座三顆腰帶的其中一顆（參宿一），是一片細長但模糊的地帶，紅色的部分為發射星雲，來自於氫原子光譜的紅色譜線（H-Alpha 譜線）。

IC434 其中較為黯淡如「馬頭」的形狀，就是襯托 IC434 的馬頭星雲。馬頭星雲距離地球大約 1,500 光年，由黑暗的塵埃和旋轉的氣體構成，在可見光波段下是不可見的，但用紅外光（如哈伯望遠鏡的紅外光設備）是可以見到色彩的哦！

前幾年有挑戰用未改的單眼相機拍 IC 434，但這片紅色星雲沒有改機下很難拍，宣告失敗，今年 2025 年第一拍，就獻給 IC 434 吧～

The weather in northern Taiwan is really bad. I have been waiting for more than a month for such a clear night. I had to take pictures even if I had a cold! However, the wind in Hsinchu was too strong, and several relatively strong gusts caused the guide star to fail. The shooting was originally supposed to take four hours, but it took a lot of time to recalibrate the guide star, and ended in more than three hours XD

The target is IC 434, located in one of the three belts of Orion (Alnitak). It is a slender but fuzzy zone. The red part is the emission nebula, which comes from the red line of the hydrogen atomic spectrum (H -Alpha spectral line).

One of the fainter "Horse Head" shapes in IC434 is the Horsehead Nebula that sets off IC434. The Horsehead Nebula is about 1,500 light-years away from Earth. It is composed of dark dust and rotating gas. It is invisible in the visible light band, but colors can be seen using infrared light (such as the Hubble Telescope's infrared light equipment).

A few years ago, I had the challenge of photographing IC 434 with an unmodified single-lens camera, but this red nebula was difficult to photograph without the modified camera, so it failed. The first shot of in 2025 will be dedicated to IC 434!

———

• iOptron GEM28

• William Optics REDCAT 51 WIFD

• ZWO ASI 2600MC Duo

• ZWO ASIAIR Mini

• Antlia RGB ULTRA

• 2025/01/04

• Dark: 20

• flat: 40

• light: 40 * 300s (total 3.3 hr)

• bias: 40

• ★★ PixInsight processing

  • Weigthed Batch Processing

  • DynamicBackgroundExtraction

  • AutomaticBackgroundExtractor

  • SCNR

  • ImageSolver

  • PhotometricColorCalibration

  • NoiseXTerminator

  • StarNet

  • HistogramTransformation

  • ColorSaturation

  • PixMath

• Photoshop crop & add logo

【Date】2024/11/30

【Pic Info】
昴宿星團從前年就開始拍攝，但是用單眼 120 mm 的焦段，因此細節其實沒有拍得很明顯。今年當也要用望遠鏡拍囉！

其實一直在思考為什麼我的照片會有一種粉蠟筆塗色的感覺，後來看其他同好分享，應該是 Bias（偏壓）沒有拍，或者是降噪沒做好，因此刷了 60 $USD 買了 PixInsight 的 AI 降噪外掛「NoiseXTerminator」。使用結果其實蠻不錯的，比我自己人工除噪的效果更好，而且處理速度挺快的，之前一直觀望沒買太可惜了。不過下次後製前，還是要準備好偏壓場才行。

簡單介紹昴宿星團，它也稱作「七姐妹星團」，在郊區可以用肉眼辨識，是一個大而明亮的疏散星團。昴宿星團中的藍色星雲便是反光星雲，是中心藍色高溫星的星，光照射在周圍的物質上而形成，就像是大霧中籠罩在燈光周圍的情景。另外它相當年輕，約一億年左右，恐龍出現的時間都比昴宿星團還早呢！

The Pleiades has been photographed since the year before last, but the camera has a focal length of 120 mm, so the details are not very obvious. This year I will also use a telescope to take pictures!

In fact, I have been thinking about why my photos have a pastel-colored feeling. Later, after reading what other people shared, I guess it was because the bias was not used, or the noise reduction was not done well, so I spent 60 $USD to buy it. PixInsight's AI noise reduction plug-in "NoiseXTerminator". The results are actually pretty good, better than my own manual noise removal, and the processing speed is quite fast. It was a pity that I had been waiting on the sidelines and not bought it before. Although I bought a noise reduction plug-in, I still need to prepare a bias field before the next post-production.

A brief introduction to the Pleiades, also known as the "Seven Sisters", can be identified with the naked eye in suburban areas. It is a large and bright open star cluster. The blue nebulae in the Pleiades are reflection nebulae, which are stars of high-temperature blue stars in the center. They are formed when light shines on the surrounding material, just like the scene surrounding the light in a heavy fog. In addition, it is quite young, about 100 million years old. Dinosaurs appeared earlier than the Pleiades!

———

• iOptron GEM28

• William Optics REDCAT 51 WIFD

• ZWO ASI 2600MC Duo

• ZWO ASIAIR Mini

• Antlia RGB ULTRA

• 2024/11/30

• Dark: 44 * 300s (total 3.6 hr)

• flat: 40 * 50ms

• light: 44 * 300s (total 3.6 hr)

• ★★ PixInsight processing

  • Weigthed Batch Processing

  • DynamicBackgroundExtraction

  • AutomaticBackgroundExtractor

  • SCNR

  • ImageSolver

  • PhotometricColorCalibration

  • NoiseXTerminator

  • StarNet

  • HistogramTransformation

  • ColorSaturation

  • PixMath

• Photoshop crop & add logo

【Date】2024/11/29 - 2024/11/30

【Pic Info】
成功完成補考！上一次因為亂調參數結果疊圖失敗，這一次記取教訓了。三角座本是秋天深空，入冬拍攝有個好處，就是仰角特別高，可以擋掉一些路燈或車燈。另外當晚北方高壓壟罩，下沉氣流帶來的好天氣絕對要好好把握，因此就算腳有骨裂，還是無法澆滅扛設備上頂樓的心情！

Successfully completed the make-up exam! The last time the stacking failed due to changing parameters, this time I learned my lesson. Triangle is originally a deep sky in autumn. One advantage of shooting in winter is that the elevation angle is particularly high, which can block some street lights or car lights. In addition, the good weather brought by the high pressure ridge in the north and the downdraft that night must be taken advantage of, so even if the foot is broken, it still can‘t extinguish the mood of carrying the equipment to the top floor!

———

• iOptron GEM28

• William Optics REDCAT 51 WIFD

• ZWO ASI 2600MC Duo

• ZWO ASIAIR Mini

• Antlia RGB ULTRA

• 2024/11/29 - 2024/11/30

• Dark: 60 * 300s (total 5 hr)

• flat: 40 * 50ms

• light: 60 * 300s (total 5 hr)

• PixInsight processing

  • Script > Batch Procesing > Weigthed Batch Processing: Stack 60 pic

  • DynamicBackgroundExtractio

  • SCNR: Remove green noise

  • Script > Image Analysis > ImageSolver: Set object & location

  • PhotometricColorCalibration

  • StarNet

  • HistogramTransformation

  • ColorSaturation

  • PixMath: Recombine M33 & stars

• Lightroom post production

• Photoshop crop & add logo

【Date】2024/08/30 - 2024/08/31

【Pic Info】
時序變化，時節已過二十四節氣的處暑，秋天已悄然來到，而秋天的深空代表天體就是 M31 仙女座星系。

M31 仙女座星系是距離銀河系最近的星系之一，距離地球 250 萬光年。在宇宙膨脹這個尺度下，M31 與銀河系的引力效應大於膨脹退行速度，因此在光譜上表現藍移。科學家估計在 30 億年後，銀河系會與 M31 發生碰撞，形成更大的星系。

在第一張圖中，M31 分別有兩個比較大的衛星星系。其中 M31 左側小圓點是 M32，在右下側是 M110。這兩個衛星星系都屬於橢圓星系。

[M31 Andromeda Galaxy] The time sequence has changed. The season has passed the end of the 24th solar term. Autumn has quietly arrived, and the representative celestial body in the deep sky of autumn is the M31 Andromeda Galaxy.

M31 Andromeda is one of the closest galaxies to the Milky Way, located 2.5 million light-years from Earth. At the scale of the expansion of the universe, the gravitational effect between M31 and the Milky Way is greater than the expansion and recession speed, so it exhibits a blue shift in the spectrum. Scientists estimate that in 3 billion years, the Milky Way will collide with M31 to form a larger galaxy.

In the first picture, M31 has two relatively large satellite galaxies. The small dot on the left side of M31 is M32, and the small dot on the lower right side is M110. Both satellite galaxies are elliptical galaxies.

———

• iOptron GEM28

• William Optics REDCAT 51 WIFD

• ZWO ASI 2600MC Duo

• ZWO ASIAIR Mini

• Antlia RGB ULTRA

• 2024/08/30 - 2024/08/31

• Dark: 60 * 300s (total 5 hr)

• Flat: 40 * 50ms

• Light: 60 * 300s (total 5 hr)

• ★★ PixInsight processing:

  • Script > Batch Procesing > Weigthed Batch Processing: Stack 60 pic

  • DynamicBackgroundExtraction

  • SCNR: Remove green noise

  • Script > Image Analysis > ImageSolver: Set object & location

  • SpectrophotometricColorCalibration

  • StarNet

  • HistogramTransformation

  • ColorSaturation

  • RangeSelection & Create Mask

  • PixMath: Recombine M31 & stars

• ★★ Lightroom post production

• ★★ Photoshop crop & add logo

【Date】2024/08/02

【Pic Info】
螺旋星雲乍聽之下可能會讓人誤會，但如果說是「上帝之眼」、「索倫之眼」，或許大家就會知道是什麼星雲了。

與 M27 啞鈴星雲一樣，NGC 7293 也是一個行星狀星雲，星雲中央藍白色的天體，未來也會變成一顆白矮星。它距離地球約 655 光年，位於寶瓶座，是距離我們最近的行星狀星雲之一。NGC 7293 直徑約為 5.1 光年，比太陽到比鄰星 4.22 光年還要長，可見它拋射和膨脹的速度非常快。

[NGC 7293 Helix Nebula] The Helix Nebula may be misleading at first, but if it is called the “Eye of God” or the “Eye of Sauron”, maybe everyone will know what nebula it is.

Like the M27 Dumbbell Nebula, NGC 7293 is also a planetary nebula. The blue-white object in the center of the nebula will also become a white dwarf star in the future. It is about 655 light-years away in the constellation Aquarius and is one of the closest planetary nebulae to us. NGC 7293 has a diameter of about 5.1 light-years, which is longer than the 4.22 light-years from the Sun to Proxima Centauri. This shows that it is ejected and expanded very quickly.

———

• iOptron GEM28

• William Optics REDCAT 51 WIFD

• ZWO ASI 2600MC Duo

• ZWO ASIAIR Mini

• Antlia RGB ULTRA

• 2024/08/02

• Dark: 14 * 600s (total 2.3 hr)

• Flat: 40 * 50ms

• Light: 14 * 600s (total 2.3 hr)

• ★★ PixInsight processing:

  • Script > Batch Procesing > Weigthed Batch Processing: Stack 14 pic

  • DynamicBackgroundExtraction

  • SCNR: Remove green noise

  • Script > Image Analysis > ImageSolver: Set object & location

  • SpectrophotometricColorCalibration

  • StarNet

  • HistogramTransformation

  • ColorSaturation

  • RangeSelection & Create Mask

  • PixMath: Recombine M51 & stars

• ★★ Lightroom post production

• ★★ Photoshop crop & add logo

【Date】2024/08/01

【Pic Info】
這週拍攝的深空天體主要以行星狀星雲為主。照片這張就是 M27 啞鈴星雲。啞鈴星雲位於狐狸座，視星等大約七等左右，是個挺明亮的深空天體，且視直徑不會太小，是個業餘天文愛好者常觀察與拍攝的天體之一。

介紹一下行星狀星雲。雖然名字包含「行星」，卻和行星沒有任何關係。它是與太陽差不多大的恆星，在生命晚期（也就是紅巨星晚期階段）恆星外層的氣體殼被強勁的恆星風吹送進太空，高溫產生電離之後，發出的色彩鮮艷的螢光。也就是說，行星狀中心的星雲，最終將會變成白矮星，而我們的太陽也將會在 50 億年後進入紅巨星，在恆星生命結束後變成白矮星。

[M27 Dumbbell Nebula] The deep sky objects photographed this week are mainly planetary nebulae. This photo is of the M27 Dumbbell Nebula. The Dumbbell Nebula is located in the constellation Vulpecula, with an apparent magnitude of approximately seventh magnitude. It is a very bright deep-sky object, and its apparent diameter is not too small. It is one of the objects that amateur astronomers often observe and photograph.

Introducing planetary nebulae. Although the name contains ”planet“, it has nothing to do with planets. It is a star about the same size as the sun. In the late stage of its life (that is, the late stage of a red giant), the outer gas shell of the star is blown into space by strong stellar winds. After being ionized by high temperature, it emits brightly colored fluorescence. In other words, the nebula in the planetary center will eventually become a white dwarf star, and our sun will also enter a red giant star in 5 billion years and become a white dwarf star after the end of the star‘s life.

———

• iOptron GEM28

• William Optics REDCAT 51 WIFD

• ZWO ASI 2600MC Duo

• ZWO ASIAIR Mini

• Antlia RGB ULTRA

• Dark: 60 * 120s (total 2 hr)

• Flat: 40 * 50ms

• Light: 60 * 120s (total 2 hr)

• ★★ PixInsight processing:

  • Script > Batch Procesing > Weigthed Batch Processing: Stack 60 pic

  • DynamicBackgroundExtraction

  • SCNR: Remove green noise

  • Script > Image Analysis > ImageSolver: Set object & location

  • SpectrophotometricColorCalibration

  • StarNet

  • HistogramTransformation

  • ColorSaturation

  • RangeSelection & Create Mask

  • PixMath: Recombine M51 & stars

• ★★ Lightroom post production

• ★★ Photoshop crop & add logo

【Date】2024/07/11 UTC+8 21:10 - 23:37

【Pic Info】
第一次處理這麼小的深空天體，也是第一次使用 PixInsight 後製。年初花了 300 歐元，比免費的後製軟體效果更好，不過進階文書機（筆電 CPU i5 8th & 8G RAM）處理速度還是稍慢些，光是疊圖就疊了三個小時，這張圖總共後製 10 小時才完成！！

因沒有拍暗場，熱噪點比較多，這也是下一次可以改進的地方

介紹一下 M51。M51 位於獵犬座，距離地球 2,300 萬光年，是天文學最著名的一對重力交互作用星系。最大的是 51A，另一個橘色小點 51B 是伴星系，51A 強大的重力撕扯 51B 的結構，但同時也推動恆星的誕生。

[M51 Whirlpool Galaxy] It is the first time to deal with such a small deep sky object, and it is also the first time to use PixInsight. I spent €300 EUR at the beginning of the year, and the effect is better than the free software. However, the processing speed of the laptop (CPU i5 8th & 8G RAM) is still  slower. Just stacking the pictures took three hours. This picture took a total of 10 hours of post-production! !

Because I didn’t take a dark frame, there are a lot of thermal noise. This is something that can be improved next time.

Introducing the M51. Located 23 million light-years away in the constellation Canes Canes, M51 is astronomy‘s most famous pair of gravitationally interacting galaxies. The largest one is 51A, and the other orange dot, 51B, is a companion galaxy. The strong gravity of 51A tears at the structure of 51B, but it also promotes the birth of stars.

———

• iOptron GEM28

• William Optics REDCAT 51 WIFD

• ZWO ASI 2600MC Duo

• ZWO ASIAIR Mini

• Antlia RGB ULTRA

• 2024/07/11 72 * 120s (total 2.4 hr)

• ★★ PixInsight processing:

  • Script > Batch Procesing > Weigthed Batch Processing: Stack 72 pic

  • DynamicBackgroundExtraction

  • SCNR: Remove green noise

  • Script > Image Analysis > ImageSolver: Set object & location

  • SpectrophotometricColorCalibration

  • StarNet

  • HistogramTransformation

  • ColorSaturation

  • RangeSelection & Create Mask

  • PixMath: Recombine M51 & stars

• Lightroom post production

• Photoshop crop & add logo

【Date】2024/07/06 UTC+8

【Pic Info】
小紅貓望遠鏡今年二月入手，歷經半年不穩定的天氣，在七月終於正式開光了🤣

07/04 下班後看了一下預報，沒有雲層，直接扛著設備上頂樓。夏天最好拍的就是 M8 礁湖和 M20 三裂，相對來說是比較亮的深空天體。

礁湖和三裂星雲距離地球約 5200 光年，其中礁湖是發射星雲，三裂是發散和發射的混合星雲，兩者都有恆星形成區。

後製手法：先用 ASIAIR Mini 內疊好的 FIT 檔案在 Siril 內部色彩處理、降噪，StarNet 去星點。

[First Opening Picture] REDCAT 51 was purchased in February this year. After half a year of unstable weather, it was finally officially worked in July🤣

07/04 I checked the forecast after get off work and saw no clouds, so I carried the equipment directly to the top floor. The best target to photograph in summer are the M8 & M20 trilobite, which are relatively bright deep sky objects.

M8 & M20 Nebula are about 5,200 light-years from Earth. M8 is an emission nebula and M20 is a hybrid divergence and emission nebula, both of which contain star-forming regions.

Post-production techniques: First use the FIT files stacked in ASIAIR Mini to perform color processing and noise reduction in Siril, and use StarNet to remove stars.

———

• iOptron GEM28

• William Optics REDCAT 51 WIFD

• ZWO ASI 2600MC Duo

• ZWO ASIAIR Mini

• Antlia RGB ULTRA

• 111 * 5s

• Stacked in ASIAIR Mini

• Siril color adjust & noise reduction

• StarNet remove stars

• Lightroom post production

• Photoshop crop & add logo

【拍攝時間】2023/11/17 22:19 - 2023/11/18 00:44

【Az/Alt】113°38’45.0”　+31°10’37.1“ - 151°16’56.7”　+56°09’23.1“

【相機參數】

• iOptron SkyGuider Pro

• Nikon D750 + MS 光害濾鏡

• 120 mm (cropped)

• ISO 100

• f4

• 120s * 54 = 108 min (total exposure time)

• Edited with DSS、LR、PS

【拍攝時間】2023/07/08　UTC+8 21:54 - 23:43

【Az/Alt】

• M8   礁湖星雲（下）：162°03’48.0”　+38°33’10.9“ - 194°09’35.1”　+37°43’16.7“ 

• M20 三裂星雲（上）：161°45’33.3”　+39°57’49.0“ - 194°53’19.4”　+40°42’40.8“  - 

【相機參數】

• iOptron SkyGuider Pro

• Nikon D750 + MS 光害濾鏡

• 120 mm (cropped)

• ISO 100

• f4

• 120s * 27 = 54 min (total exposure time)

• Edited with Sequator、LR、PS

【拍攝時間】2023/01/21　UTC+8 20:31

【相機參數】

• Nikon D750 (with iOptron SkyGuider Pro )

• WB: 4000K

• ISO - 100

• F/4

• Focal Length: 120 mm

• Total Exposure: 3050 s (50 pics)

• Stacked with Sequator

• Edited with Adobe Lightroom & Photoshop

【拍攝時間】2022/09/28　UTC+8 22:14 - 23:09

【相機參數】

• Nikon D750 (with iOptron SkyGuider Pro )

• WB: Auto & 4000K

• ISO - 100

• F/4

• Focal Length: 120 mm

• Total Exposure: 1256 s (20 pics)

• Stacked with Sequator

• Edited with Adobe Lightroom & Photoshop