I What Are These Mysterious Objects Spotted Near Orion?

[Hijole]

Hi all!

I am new here :)

I was observing Orion with the astro software Aladin and I found two similar relatively weird objects. I would like to share with you the image, with the zoom on each of them.

Any explanation? Could they be the same object (a satellite?) seen in two different moments?

Thank you!

 

[Ibix]

Looks like an internal reflection from the telescope to me - the dark region in the middle is the secondary mirror and the + pattern is its supports.

Paging a few of the astrophotographers - @collinsmark, @DennisN, @davenn.

 

[DaveC426913]

Almost certainly what that is, yes. What make/brand of scope is it?
(It's obviously a reflector, so Schmidt-Cass, Newtonian or Dob).

Wait, this is a sim??

I think we need some context. What is the relationship between the three pics you've uploaded?

 

[Hijole]

Thanks!

The image is from the Digitized Sky Survey, a ground-based imaging survey of the entire sky, performed with Palomar and UK Schmidt telescopes, producing photographic plates that were later digitized.

 

[DaveC426913]

Oh. OK, I see the context now. A and B are labeled in the primary image. The right images are blow ups.

Here are some example 4-vane double spiders :

Here is where the "spider" goes in a generic reflector scope:

So the data that your Aladin software is using must be including these artifacts of the Palomar and UK Schmidt scopes.

 

[phyzguy]

These are definitely internal reflections inside the telescope. They are usually referred to as "ghosts". They are usually associated with bright stars. No optical system is perfect, and it is very difficult to eliminate these because the bright stars are so much brighter than the surrounding regions. A is probably associated with Sirius in the lower left, and B could be a second ghost associated with Sirius or a ghost associated with Rigel.

 

[Hijole]

Oh. OK, I see the context now. A and B are labeled in the primary image. The right images are blow ups.

Here are some example 4-vane double spiders :
View attachment 288680
View attachment 288681

Here is where the "spider" goes in a generic reflector scope:
View attachment 288682
View attachment 288683

So the data that your Aladin software is using must be including these artifacts of the Palomar and UK Schmidt scopes.

Very clear, thank you! :)

 

[Hijole]

These are definitely internal reflections inside the telescope. They are usually referred to as "ghosts". They are usually associated with bright stars. No optical system is perfect, and it is very difficult to eliminate these because the bright stars are so much brighter than the surrounding regions. A is probably associated with Sirius in the lower left, and B could be a second ghost associated with Sirius or a ghost associated with Rigel.

Hi phyzguy,

Thanks! Now I see, but why internal reflections are produced in the case of bright stars? Is also possible having ghosts in the case of other bright sources like quasars?

 

[phyzguy]

Hi phyzguy,

Thanks! Now I see, but why internal reflections are produced in the case of bright stars? Is also possible having ghosts in the case of other bright sources like quasars?

Light is supposed to follow a certain path through the optical system, but there are always unintended refections. This site shows some ghost images that appear in the Hubble Space Telescope. Any object will have a ghost associated with it, but as the object gets fainter the ghost eventually gets so faint that it is undetectable. In theory a quasar will have a ghost associated with it, but the brightest known quasar (3C273) is about a million times fainter than Sirius, so the ghost would be invisible.

 

[Hijole]

Light is supposed to follow a certain path through the optical system, but there are always unintended refections. This site shows some ghost images that appear in the Hubble Space Telescope. Any object will have a ghost associated with it, but as the object gets fainter the ghost eventually gets so faint that it is undetectable. In theory a quasar will have a ghost associated with it, but the brightest known quasar (3C273) is about a million times fainter than Sirius, so the ghost would be invisible.

Thank you for the clear (qualitative and quantitative) explanation!

 

[davenn]

Looks like an internal reflection from the telescope to me - the dark region in the middle is the secondary mirror and the + pattern is its supports.

Paging a few of the astrophotographers - @collinsmark, @DennisN, @davenn.

totally agree and it's Newtonian with the secondary and it's spider bracket -- as has been noted