Clear Skies
June 26th, 2022, 09:42 AM
R.A./Dec.: 17:01:04 -04d13m00s
Constellation: Ophiuchus
Object type: suspected reflection nebula
Us visual astronomers... we gaze at the heavens. We study, we explore, we discover. Using little more than mirrors, lenses and our Mk1 eyeball. But even when the objects we observe were listed in catalogs well over a century ago, the observations are always our own. With every object we observe, be it a first observation or a visit to one observed before, we produce our own findings, we gather our own data, we discover what can be seen and - let's not forget - we experience the personal joy that comes with it.
In this day and age the skies have been thoroughly combed by professional observatories. The complete sky captured on photographic plates and space telescopes going ever deeper. When we are out observing and we notice a smudge in our eyepiece, we can quickly determine the name and nature of the object, using maps and applications that are available at our fingertips. Even new comets are grabbed from us before they get a chance to brighten sufficiently to be picked up visually. Is there anything left for us amateurs to discover..?
Over the years, compiling my observing guides (https://clearskies.eu/csog/), I have downloaded literally hundreds of thousands of DSS images. Mostly newer ones (POSS2), some older (POSS1) whenever a plate has a defect or when an objects is near a plate's edge. By doing so I have added a great many objects (mostly galaxies) to my guides, along with an ever growing list of what I call 'big scope objects'; the faintest, weirdest blobs that I have come across and that I dream of one day (night) observing in a truly large telescope. It amazes me how much remains to be observed and I realise that a human life is, sadly, too short to observe it all. But we can at least try to make a dent.
In November, I was compiling my first 'binocular guides'. Nothing fancy, just the largest decent DSS image I can find, in an unmirrored orientation, along with minimal data for the object. By doing so, I downloaded many 2 degree images, the largest size the DSS server will allow. One of these images was for the globular cluster Messier 10 (NGC6254), in Ophiuchus.
4766
What immediately caught my eye, was the bright star on the far left side of the image, about one degree to the east of the globular. No doubt that there's a nebula (visually) surrounding that star, most prominent to the south of it. As always, I went on the prowl to find out what it was. For starters, I downloaded images from other plates, taken at different times and/or different wavelengths, to determine that it is in fact a nebula and not an image artefact. If an "object" can only be seen on a single plate, but not on any other image, it is very likely to be a plate fault. This nebula was no fault, it is real. Next, I added the object to an AstroPlanner planfile to see if there is any catalog in the application that contains it. This taught me that the star involved is 30 Ophiuchi (https://en.wikipedia.org/wiki/30_Ophiuchi), shining bright at magnitude 4.8 with a spectrum of K4. The two stars that flank it, to the east of 30 Oph, are components of the double star Engelmann 59 (WDS17011-0413 (https://www.stelledoppie.it/index2.php?menu=29&iddoppia=68333)) of which 30 Oph is the primary. It was first cataloged as a double in the year 1887. On to SIMBAD (http://simbad.u-strasbg.fr/simbad/sim-id?Ident=30+oph&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id) and NED (http://ned.ipac.caltech.edu/byname?objname=30+oph&hconst=67.8&omegam=0.308&omegav=0.692&wmap=4&corr_z=1) to look for more data. All came up empty. To my surprise this relatively large and bright nebula, surrounding a naked eye star, was never listed.
Let's take a closer look at the nebula. Below are 30' POSS2 images in blue and red and a 2 degree image centered on 30 Oph @ 17:01:04 -04d13m00s.
4767 4768 4769
The nebula is much clearer in blue, giving reason to suspect it being a reflection nebula. Its brightest wisps span about 5 minutes of arc, east to west. The PanSTARRS image in Aladin (http://aladin.unistra.fr/AladinLite/?target=17%2001%203.602-04%2013%2021.52&fov=0.50&survey=P%2FPanSTARRS%2FDR1%2Fcolor-z-zg-g) shows it rather well, too. Are there other images out there? There must be, since it is so close (within a degree) of a Messier object. Unfortunately, there are very few. The prettiest one I was able to find is by Belgian astrophotographer Dominique Dierick, posted on Flickr (https://www.flickr.com/photos/dodi-belgium/49855938937).
Since stumbling upon this object, I have scrutinised the web looking for information. The only paper I found is this one (https://iopscience.iop.org/article/10.1086/307064/pdf); it notes dust surrounding 30 Oph and other stars. But I can not determine whether or not that is the nature of the nebula visible on the POSS plates.
So can I claim this 'discovery' as mine? Well... I dunno. I reported it on the Deep Sky Hunters Group (https://groups.io/g/deepskyhunters/message/96). That's about all I can do as an amateur. Objects get designations whenever a formal research paper is published. Such a thing is out of my league, but on my list of potential discoveries (no more than that) I have included it as object nr. 75 (https://clearskies.eu/astronomy/discoveries51-75#75). If there is any more data out there, if this nebula was recognised, studied and designated, I would love to hear about it.
The question is: can this nebula be observed using amateur equipment..? It will require some aperture, but I do suspect it to be within reach of larger amateur telescopes. Even when the glare of 30 Ophiuchi will undoubtedly make it a challenge. That's why I thought it would make a nice OOTW.
As always, I have compiled an observing guide that can be downloaded here (https://clearskies.eu/csog/downloads/dsfootw2022#26).
4770 4772
Now get out there, swing your scope to the center of the constellation of Ophiuchus, find M10, then pan a degree due east until you find a bright ruddy star. Be sure to report back to let us know what you observed!
Constellation: Ophiuchus
Object type: suspected reflection nebula
Us visual astronomers... we gaze at the heavens. We study, we explore, we discover. Using little more than mirrors, lenses and our Mk1 eyeball. But even when the objects we observe were listed in catalogs well over a century ago, the observations are always our own. With every object we observe, be it a first observation or a visit to one observed before, we produce our own findings, we gather our own data, we discover what can be seen and - let's not forget - we experience the personal joy that comes with it.
In this day and age the skies have been thoroughly combed by professional observatories. The complete sky captured on photographic plates and space telescopes going ever deeper. When we are out observing and we notice a smudge in our eyepiece, we can quickly determine the name and nature of the object, using maps and applications that are available at our fingertips. Even new comets are grabbed from us before they get a chance to brighten sufficiently to be picked up visually. Is there anything left for us amateurs to discover..?
Over the years, compiling my observing guides (https://clearskies.eu/csog/), I have downloaded literally hundreds of thousands of DSS images. Mostly newer ones (POSS2), some older (POSS1) whenever a plate has a defect or when an objects is near a plate's edge. By doing so I have added a great many objects (mostly galaxies) to my guides, along with an ever growing list of what I call 'big scope objects'; the faintest, weirdest blobs that I have come across and that I dream of one day (night) observing in a truly large telescope. It amazes me how much remains to be observed and I realise that a human life is, sadly, too short to observe it all. But we can at least try to make a dent.
In November, I was compiling my first 'binocular guides'. Nothing fancy, just the largest decent DSS image I can find, in an unmirrored orientation, along with minimal data for the object. By doing so, I downloaded many 2 degree images, the largest size the DSS server will allow. One of these images was for the globular cluster Messier 10 (NGC6254), in Ophiuchus.
4766
What immediately caught my eye, was the bright star on the far left side of the image, about one degree to the east of the globular. No doubt that there's a nebula (visually) surrounding that star, most prominent to the south of it. As always, I went on the prowl to find out what it was. For starters, I downloaded images from other plates, taken at different times and/or different wavelengths, to determine that it is in fact a nebula and not an image artefact. If an "object" can only be seen on a single plate, but not on any other image, it is very likely to be a plate fault. This nebula was no fault, it is real. Next, I added the object to an AstroPlanner planfile to see if there is any catalog in the application that contains it. This taught me that the star involved is 30 Ophiuchi (https://en.wikipedia.org/wiki/30_Ophiuchi), shining bright at magnitude 4.8 with a spectrum of K4. The two stars that flank it, to the east of 30 Oph, are components of the double star Engelmann 59 (WDS17011-0413 (https://www.stelledoppie.it/index2.php?menu=29&iddoppia=68333)) of which 30 Oph is the primary. It was first cataloged as a double in the year 1887. On to SIMBAD (http://simbad.u-strasbg.fr/simbad/sim-id?Ident=30+oph&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id) and NED (http://ned.ipac.caltech.edu/byname?objname=30+oph&hconst=67.8&omegam=0.308&omegav=0.692&wmap=4&corr_z=1) to look for more data. All came up empty. To my surprise this relatively large and bright nebula, surrounding a naked eye star, was never listed.
Let's take a closer look at the nebula. Below are 30' POSS2 images in blue and red and a 2 degree image centered on 30 Oph @ 17:01:04 -04d13m00s.
4767 4768 4769
The nebula is much clearer in blue, giving reason to suspect it being a reflection nebula. Its brightest wisps span about 5 minutes of arc, east to west. The PanSTARRS image in Aladin (http://aladin.unistra.fr/AladinLite/?target=17%2001%203.602-04%2013%2021.52&fov=0.50&survey=P%2FPanSTARRS%2FDR1%2Fcolor-z-zg-g) shows it rather well, too. Are there other images out there? There must be, since it is so close (within a degree) of a Messier object. Unfortunately, there are very few. The prettiest one I was able to find is by Belgian astrophotographer Dominique Dierick, posted on Flickr (https://www.flickr.com/photos/dodi-belgium/49855938937).
Since stumbling upon this object, I have scrutinised the web looking for information. The only paper I found is this one (https://iopscience.iop.org/article/10.1086/307064/pdf); it notes dust surrounding 30 Oph and other stars. But I can not determine whether or not that is the nature of the nebula visible on the POSS plates.
So can I claim this 'discovery' as mine? Well... I dunno. I reported it on the Deep Sky Hunters Group (https://groups.io/g/deepskyhunters/message/96). That's about all I can do as an amateur. Objects get designations whenever a formal research paper is published. Such a thing is out of my league, but on my list of potential discoveries (no more than that) I have included it as object nr. 75 (https://clearskies.eu/astronomy/discoveries51-75#75). If there is any more data out there, if this nebula was recognised, studied and designated, I would love to hear about it.
The question is: can this nebula be observed using amateur equipment..? It will require some aperture, but I do suspect it to be within reach of larger amateur telescopes. Even when the glare of 30 Ophiuchi will undoubtedly make it a challenge. That's why I thought it would make a nice OOTW.
As always, I have compiled an observing guide that can be downloaded here (https://clearskies.eu/csog/downloads/dsfootw2022#26).
4770 4772
Now get out there, swing your scope to the center of the constellation of Ophiuchus, find M10, then pan a degree due east until you find a bright ruddy star. Be sure to report back to let us know what you observed!