Disk Detective Talk

Arcmins ?

  • shocko61 by shocko61

    I used AWI0002nzc Good Candidate or not to see what is in NED and there is J202339+46358 RadioS which has a separation from central target of 1.854 arcmins . My question is how large can the arcmins separation be without missing the central target ?? I realise that the acrmin angular distance changes as the object gets closer or further away , which complicates things beyond what I understand . I think 1.854 arcmins is Too much but I do not yet have a clear idea of the distances involved in arcmins and arcsecs . help please any one . Ian

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  • onetimegolfer by onetimegolfer

    Hi shocko61 (Ian I think) , Im onetimegolfer (Phillip) I wanted to respond; which will get corrected by a moderator if any part is wrong so here goes: Always use .2 arcmin in all searchs ;That's point two (.2) translated to arcsec that is 12 arc sec. A lot can be in that area besides a star depending on the distance as you have stated. NED VSX Vizier Skyserver start out in arcmin so its easier to transform to arcsec just by using .2 arcminutes. Now with that said ; I find that even though this object is listed in SIMBAD as a star I tend not to believe that; here is why: the Aladdin that is provided seems way out of shape; NED listing is too off of target at 1.854 with no object found at .2 arcmin ; Although it looks good till you get to W4 when the object is outside the circle there is also another object closeby.(which multiple #1 cannot be used even at this point) With the extended #3 I would have to say this is not a good-candidate; I believe there is more than one object there. Very close together. Radio source? Could be a galaxy as I found nothing in NED VSX or Skyserver.I still have a great deal of problem with Vizier. I think it has to do with the distance thing. OK moderators work me over shocko61 and I are inquiring minds.

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  • shocko61 by shocko61

    Hi onetimegolfer , Phillip , You are correct , Ian here , when I was a Kid got told off for asking too many questions 😅 I will have to study what you have said but once over it makes sense . And it explains why in NED I do not get very much with the arc min set to 0.2 . I seem to have the same sort of problem with VizieR too . but I am a bit wiser thank you very much for you kind help . Cheers ,Ian

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  • onetimegolfer by onetimegolfer in response to shocko61's comment.

    The guys we are working for are really smart but they sure don't mind answering questions. Sometimes they let us slip in a good thing like #noAO lol hang in there. Phillip

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  • voyager1682002 by voyager1682002 moderator in response to shocko61's comment.

    Ian, this object is not a good candidate because it's extended in WISE 4. According to SIMBAD, this object is 0.14 arcsec away. Have a look at this blog post: http://blog.diskdetective.org/2014/02/02/the-power-and-danger-of-simbad/ Marc talks about arcseconds in relation to SIMBAD.
    I hope this answer your question 😃

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  • anoxie by anoxie

    and spectral type wK3III

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  • shocko61 by shocko61 in response to onetimegolfer's comment.

    Yes Phillip , I am pleased they also have a good sense of humour other Wise ( pun intended ) I would be facing the firing squad lol 😉 . Cheers , Ian

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  • shocko61 by shocko61 in response to voyager1682002's comment.

    Hi voyager1682002 , I looked at it for a second time and now do not know why I asked (good ?) but I take everything on board and the blog may well be a way for me to get more info in general , I can keep them writing for years 😉 seriously though you people are all very helpful and I cannot ask for more than that, and yes that did answer the question . Thankyou very much Cheers ,Ian

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  • shocko61 by shocko61 in response to anoxie's comment.

    Hi anoxie , spectral types are another kettle of fish , I can feel another learning curve coming on , more pain killers please , 😉 thank you for your help . Cheers ,Ian

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