I don't know, next to an Einstein ring, they look to me like nincompoops.Not intended to indicate substandard mental prowess, their popular names refer to their similar, dumbbell or hourglass shapes.
http://apod.nasa.gov/apod/ap080728.html
I don't know, next to an Einstein ring, they look to me like nincompoops.Not intended to indicate substandard mental prowess, their popular names refer to their similar, dumbbell or hourglass shapes.
http://apod.nasa.gov/apod/ap081217.htmljimmysnyder wrote:From today's APOD:I don't know, next to an Einstein ringNot intended to indicate substandard mental prowess, their popular names refer to their similar, dumbbell or hourglass shapes.
they look to me like nincompoops.
Apparentlyrstevenson wrote:I notice that the sizes of, and therefore the distances to, the two nebulae given in the linked pages in the last line of the APOD post, differ considerably from the sizes and distances given in the APOD post. Is there that much disagreement about these things, still?
It's not quite as bad as the previous post would suggest. M27 is close enough that conventional stellar parallax measurements can be made, using the HST or Hipparcos. Consequently, its distance is known with at least reasonable precision to be 1350 ly (+150, -200). M76 is too far away to use parallax measurements with our current instrumentation, so it does have quite a large uncertainty in distance.rstevenson wrote:Thank you for that. Though I am shocked to my very core by this lack of precision.
`I know what you're thinking about,' said Tweedledum; `but it isn't so, nohow.'DavidLeodis wrote:In the explanation to the APOD it states the "images were made at the same scale, so the apparent size difference is mostly because one is closer". I am unsure though if their apparent position to each other is as seen in the picture, that is can they be seen together like they appear, or is it just a picture showing an image of each nebula that have just been put next to each other but which in reality cannot be seen together. I hope that makes sense about what I'm trying to find out!
They are not in the same part of the sky and can not be seen together.DavidLeodis wrote:In the explanation to the APOD it states the "images were made at the same scale, so the apparent size difference is mostly because one is closer". I am unsure though if their apparent position to each other is as seen in the picture, that is can they be seen together like they appear, or is it just a picture showing an image of each nebula that have just been put next to each other but which in reality cannot be seen together. I hope that makes sense about what I'm trying to find out!
The two objects are in different parts of the sky (70° separation). You're seeing two images side-by-side. In fact, if you can't see the rather obvious division between the two, which is darker than the sky background, your monitor is too dark, and needs adjustment. Check this grayscale bar and make sure you can see all 13 segments.DavidLeodis wrote:In the explanation to the APOD it states the "images were made at the same scale, so the apparent size difference is mostly because one is closer". I am unsure though if their apparent position to each other is as seen in the picture, that is can they be seen together like they appear, or is it just a picture showing an image of each nebula that have just been put next to each other but which in reality cannot be seen together. I hope that makes sense about what I'm trying to find out! :)
I'm pretty sure the names were bestowed by visual observers. Certainly, through a telescope, these objects are much easier to see as dumbbell shaped (that's because, as is usual for DSOs, you can't see much through a telescope except for faint gray fuzzy things, with little detail. So the outside shape is about all that's available for naming). Many objects, when imaged in detail, don't show much of their visual-based name characteristics.zbvhs wrote:To my eye, The Dumbbells aren't shaped like dumbbells (the kind that weight-lifters use) but are more toroidal in shape with jets coming out of the doughnut hole.
They look more like DumbledoresChris Peterson wrote:I'm pretty sure the names were bestowed by visual observers. Certainly, through a telescope, these objects are much easier to see as dumbbell shaped (that's because, as is usual for DSOs, you can't see much through a telescope except for faint gray fuzzy things, with little detail. So the outside shape is about all that's available for naming). Many objects, when imaged in detail, don't show much of their visual-based name characteristics.zbvhs wrote:To my eye, The Dumbbells aren't shaped like dumbbells (the kind that weight-lifters use) but are more toroidal in shape with jets coming out of the doughnut hole.