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IAU Submission: Additional Data Requested of Possible Undesignated Planetary Nebula in Cygnus
Keith B Quattrocchi MD,
PhD and Mel Helm, MD
September 9, 2008
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Section I
(Septemper 8, 2008)
Dan: This website will be used to give you accurate answers to your questions. Each section will correspond
to an email. The following is the first email which you sent to me:
Is your object visible on non-H_alpha images? What is its brightness
in the H_alpha
passband (and in other passbands if visible outside of
H_alpha)? Have you checked all Palomar Sky Survey images
to see if it
is visible there? Have you checked ADS for possible published papers
or articles mentioning it over
the past century?
Thanks, Dan Green
I will attempt to answer each question separately.
1) The figure below is the RGB uncropped image. Even with extreme stretching of
the Data I am not able to see the object. The same is true of the Luminance image just below.
| RGB of Possible Undesignated PN in Cygnus |
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| kbq July 2008 |
| Luminance of Possible PN in Cygnus |
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| KBQ July 2008 |
2) You have asked about the objects surface bightness. Keep in mind, we are not professionals.
However, my understanding is that Surface Brightnesses is measured in magnitudes per square
arcsecond, and is a logrithmic function. Looking this up, I see that surface brightness is specifically a
function of the magnitude (m) extending over an area of (A) in square arcseconds. Specifically S=m + 2.5(logA).
Looking at the H-alpha data (image below) our object is 4.08 arc-min in diameter (average, object is slightly oval).
The area is therefore 13.07 arc-min2. The average ADU of the nebulosity is 43.2 (average of 10 measurements)
and the average FWHM ADU of the star above the bubble (GCS 3151:2557) is about 7,303 ADU (average of 10 measurements
in Maxim DL) at a known magnitude 9.48. With a magnitude differential of 2.512/magnitude, the approximate magnitue difference
between these two objects would be 5.4. This puts the approximate value of the bubbles magnitude at 14.88. Since
S= m + 2.5(logA) we get S= 14.88 + 2.5 (log 13.07) = 15.99 mag/arc-secē
I have included the raw, non-manipulated
Ha, OIII and SII frames below. Each are from the 16"/f9 RC, each subframe is 20 minutes and there ate 16-20 stacked
images in each case, calibrated in CCDStack. As you can see, there is a strong Ha and significant OIII contribution,
but there is almost no SII contribution.
| H-alpha Possible Undesignated PN in Cygnus |
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| KBQ, July 2008 |
| OIII Possible Undesignated PN in Cygnus |
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| KBQ July 2008 |
| SII of Possible Undesignated PN in Cygnus |
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| KBQ July 2008 |
3) We have done an extensive review,
to the best of our ability. We have thoroughly investigated all listed objects on the CDS database, including Simbad.
This is detailed on the following link, which I believe you have reviewed: http://www.lostvalleyobservatory.com/review.nebula1/ . I also checked the ADS site (http://adswww.harvard.edu/ ), and was not able to find any article regarding this PN in Cygnus. I have searched the Palomar Sky Survey ( http://stdatu.stsci.edu/dss/ ) including the POSS2 (Red/Blue/IR), POSS1 (R/B), HST (GSC 1 and2) and could not find the object designated.
As I note in the website write-up, it can faintly be seen on the DSS, but was not designated (it was evidently over looked
due it's extreme faintness). The closest designated object seems to be an XRay source, as I previously noted, in the
bubble but not at it's center ( http://www.lostvalleyobservatory.com/review.nebula1/ ). I have consulted both professionals and accomplished amateur astronomers as well, without anyone able to find
evidence of a prior recognition of this object.
4) As an aside, again I am told that this object was also submitted to you (IAU) by
Dave Jurasevich (Superintendent of the Mt Wilson Observatory). I understand he submitted this object on July 10, 2008,
having imaged it on July 6, 2008. He did not post his find publically until after we had independantly seen and posted
the object (July 17, 2008). I understand he also submitted my website data at some point, evidently running across my
posting on the internet (and kindly wanting the IAU to be aware of our information on this object). If my
information is correct, it appears we have independantly discovered this object, but it is of note that he imaged
it on July 6 (11 days before us) and submitted his data on July 10, 2008 (personal communication from Dave Jurasevich),
several days prior to our posting the object publically on my website. Prior to receiving this information
from Dave Jurasevich who only first contacted us on Sunday, September 8, 2008), we had already submitted our data to
Dr. David Riddle, who we understood is putting a PN catalogue together (as recommended by Tim Puckett). This being
our first "find", we were not aware of the importance of first submitting our data to the IAU.
5) Finally, I have included an image of the central blue star, which we found with the assistance of Dana Patchick
(who works with Dr. Jacoby of the WIYN Observatory). The coordinates of the star are a near exact match to the geometric
center of the "bubble" (PN or, less likely, Wolf-Rayet Nebula). The image is shown below. It is a tri-layered
composit of RGB, Ha and Luminance data. The star is also blue on the pure RGB images. Details of the image
are available at http://www.lostvalleyobservatory.com/page30pninudcygnuscenterstar/ .
| NB/LRGB of PN in Cygnus (undesignated) |
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| KBQ |
I was struck by the vividly blue color of the star. The significance
of this is under investigation and thie site will be updated as this and other information becomes available. Please
let me know if you have any further questions.
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