HDW 2 (Hartl-Dengl-Weinberger 2) is an old planetary nebula in Cassiopeia. The popular name is Bearclaw Nebula and it has the number Sh2-200 in the Sharpless catalogue. The image was made in only 3 hours with an ASI1600mmp on a TS 130/910 mm refractor with 0.79x reducer from my balcony.. Please log in or sign up to leave a comment. Well done Pete!

2022年4月21日 · Taken from home observatory, this beautiful but faint planetary nebula, Sh2-200, was discovered in 1983 by the astronomers Herbert Hartl, Johann Dengel and Ronald Weinberger. In 1987, further narrowband observations detected a large faint outer halo extending further than the central shell.

Consisting of iridescent shades of purple and blue, this ethereal bubble represents the ghostly remains of a dying star. The category of planetary nebulae was given its name due to telescopic observations by 18th century astronomers such as William Herschel and others being described as similar in appearance and brightness to planets.

This object is known by many names - HDW 2 (Hartl-Dengl-Weinberger 2), Sharpless 2-200 and PNG 138.1+4.1. It is a beautiful and mysterious planetary nebula located 3600 light years away in the constellation of Cassiopeia. The bright portion of the nebula is only 6 minutes in diameter.

2025年1月12日 · Sh2-200 is an old planetary nebula in Cassiopeia. It has a few other names: the Bear Claw nebula, HDW2 (Hartl-Dengl-Weinberger were the discoverers, in 1983), LBN 674, and PK138+04.1. It was not confirmed as a planetary nebula until 2017, though this classification was proposed in 1987 after spectra were obtained.

Despite being very old and highly evolved, low surface brightness planetary nebulae such as SH2-200 (or HDW 2 as it is also known) contain very hot and energetic central stars, which are the remnant cores of the progenitor star that died and ejected its outer gaseous layers.

Sh2-200, the Bear Claw nebula. This nebula was first discovered by the astronomer Stewart Sharpless in 1959 who included it in his catalogue of HII regions under the name of Sh2-200. In 1983, Sh2-200 was included in the HDW catalogue of possible planetary nebulae by the astronomers Herbert Hartl, Johann Dengel and Ronald Weinberger.

2024年11月14日 · Image Description and Details: Sh2-200 (also known as HDW 2 or Bearclaw Nebula) is an extremely fait planetary nebula in the constellation Cassiopeia, about 3° northeast of the large Soul Nebula. It is a poorly studied object, which was initially cataloged as an H II region and only in 198

SH2-200 (Sharpless 200) This planetary nebula offers a lot to large telescopes and smaller ones with a wider field of view. The nebula responds mostly to the hydrogen-alpha filter and is weak with the standard color RGB filters.

撮影メモ： きりん座との境界近くのカシオペヤ座東端部に位置する，淡い惑星状星雲を捉えたものです。 視直径約6分の円形をしており，内部に筋状の構造が見られます。 その形状が主に米国でポピュラーな菓子に似ていることから，"Bear claw Nebula""というニックネームで呼ばれます。 星雲本体の周辺部には，極めて淡いHα星雲が取り巻いていることがわかります。 この星雲は，約20分北に位置する小規模な散開星団・Cr 36にまで広がっています。 Copyright (c) 2023 …