The Eta Carinae Nebula In Carinae (NGC3372)

Telescope photography from the back alley of my house and first light with the Regdoll 17 harmonic mount
I purchased a Regdoll 17 harmonic mount exactly one year ago, intending to use it on back roads and expeditions, but bad weather prevented me from seeing first light. Two and a half years ago, I moved into a house and was unable to photograph with the telescope from the back roads.
The moon was bright, but the sky looked like it would be suitable for testing the mount, so I started two days ago. On the first day, clouds appeared almost as soon as I finished assembling it. Yesterday, the second day, there were clouds at first, but by the time I started focusing and polar alignment, there was a nice clear sky. I started testing immediately after polar alignment, and the guiding results in PHD2 were pretty good. I shot 40-50 frames at 180 seconds with a 300mm focal length and a 1-inch CMOS sensor, and saw zero streaks of stars. Well, that's to be expected with a 300mm. It should be sufficient for a short focal length used on back roads and expeditions. For testing, I used the Orion Nebula and Rosette Nebula, which are standard locations for this time of year. After the test, I was bathed in starlight for the first time in a while, so I started observing and checking how much of the image I could capture with the telescope from this spot.
As expected, all I could see in the Tarantula Nebula was the wall of a house.
I wasn't expecting much, but Eta Carinae popped up on the monitor. I was surprised.
I'd only photographed it once before on a Star Party expedition a few years ago, but when I took a closer look, it came out clearly even with a 3-second plate-soving exposure. It was clearly brighter than the Orion Nebula, even at such a low altitude. And it was huge!!
There was just one problem: due to light pollution, the guide camera was completely white, making guided photography impossible. It was unacceptable that I could see it but not capture it. I tested it with no guide and tracking only at 30, 60, 120, and 180 seconds. I found that up to 120 seconds, I could capture images with about an 80% yield, although there were occasional streaks of stars. It's a pretty good mount. This has become a long story, but the first light of the day is the Eta Carinae Nebula.
From now on, the Narrow Band target fest will begin in the low latitudes of the southern sky. I wonder how many of the many things I want to photograph will I be able to capture!!

イータ・カリーナ星雲（りゅうこつ座）

家の裏道からの望遠鏡での撮影および Regdoll 17 ハーモニック・マウントのファースト・ライト

丁度一年目に裏道や遠征時での利用を考えてRegdoll 17というハーモニック・マウントを購入したが、悪天候のためファーストライトを迎えられずにいた。2年半前に越してきた裏道からの望遠鏡での撮影も同様に一度もできていなかった。

月は明るいがマウントのテストはできそうな空だったので、２日前からトライを始めた。初日は組み立て終わったとほぼ同時に雲の襲来。２日目の昨日は最初は雲があったが、フォーカス合わせと極軸合わせを始める頃には丁度良い範囲に晴れ間があった。極軸合わせが終わりすぐテストを始めたがPHD2でのガイド結果はまずまず。焦点距離300mm,1Inch CMOSで180秒のフレームを40−50枚撮影したが星が流れることはZEROだった。まー300mmでは当たり前。裏道や遠征で使う短焦点には十分であろう。テストにはこの時期お決まりのオリオン大星雲とバラ星雲を利用した。テストが終わり、久しぶりに星の光を浴びたので、そのままこの場所から望遠鏡でどの範囲まで撮影できるか観望を兼ねてチェックを始めた。

想定通りタランチュラ星雲は人家の壁しか写らなかった。

期待はしていなかったがEta Carinaeはドカンとモニターに写し出されてきた。これには驚いた。

数年前にStar Party の遠征で一度だけ撮影したが、改めて落ち着いて観察するとPlate Sovingの3秒の露出でもクッキリ出てくる。明らかにこんなに低空でもオリオン大星雲より明るい。そして大きい！！

ただ１点問題があり光害の影響でガイドカメラは真っ白でガイド撮影ができない。見えてるのに撮れないなんて許せない。試しにNo Guideでトラッキングだけで30秒、60秒、120秒、180秒でテストしたら120秒まではたまに星が流れるが80％くらいの歩留まり撮影できることがわかった。なかなか良いマウントだ。

長話になってしまったが、ということで今回のFIrst LightはEta Carinae Nebula

これからの時期南天の低緯度はNarrow Bandターゲット祭りの始まり。山ほどある撮りたいものがどれだけ撮れるかな！！

Place: Astropical@Backyard Observatory East Pattaya Thailand (Bortle Class 8, Moon Phase 79.4%)