Dragan
April 24th, 2022, 06:27 PM
M102
NGC5866
UGC9723
Galaxy
Constellation: Draco
RA: 15 06 29.4
DEC: 55 45 48
Class: SA0+sp
Size: 6.4’x2.8’
Mag: 9.9
My choice for this week’s object came as a surprise when I realized that it had never been chosen as an OOTW! M102 is not just a delight in the eyepiece in a wide variety of instruments, but it comes with some mystery as well.
Per Seds.org, M102 was “probably” discovered by French astronomers Pierre Méchain and/or by Charles Messier in 1781. In short, Méchain recorded observing M102 (NGC5866) in late March or early April of 1781. Charles Messier included the observation by Méchain in his catalog but failed to include the coordinates, nor confirming the observation, leaving some to question exactly which object was observed by Méchain. None of this was out of the ordinary as Méchain and Messier collaborated on many of the objects that would eventually be listed in Messier’s catalog. In 1783, Méchain in a letter to then Astronomer Royal of Berlin Johann III Bernoulli, disavowed his observation of M102 stating that his observation was in fact a duplication of M101 as well as an error in his star chart.
Descriptors used at the time point to M102 not being a duplicate observation of M101. Méchain described M101 differently from M102. M101 was described as a Nebula without stars, very obscure and pretty large, between 6' and 7' in diameter, between the left hand of Bootes and the tail of Ursa Major. Difficult to distinguish when graticule lit whereas M102 was described as Nebula between the stars Omicron Bootis and Iota Draconis: it is very faint, near it is a star of 6th magnitude.
Star positions were also called into question. Whether it was Mechain’s own star designation or the possibility that there was a misprint in the star catalog he was using at the time is up for debate but the most likely scenario was the latter rather than the former.
To add more drama, Herschel “independently” discovered this object in 1788! So, who knows what’s going on?! :D:thinking:
Most probable is that M102 is in fact NGC5866. Either way, the story continues and leaves for some interesting reading material for anyone interested in coming up with their own conclusions. If you look at this link (https://www.messier.seds.org/more/m102d_more.html), you’ll see many people have differing opinions on the matter! And please feel free to read up on the fascinating history of this object here (https://www.messier.seds.org/m/m102d.html). I’m sure Steve Gottlieb with his vastly more knowledge than myself can add even more to this interesting story.
Visually, who hasn’t seen M102?! It’s a beautifully stunning object in all sizes of telescopes – even showing itself in binoculars from dark sites. M102 reveals itself as a bright, elongated NW-SE nearly edge-on galaxy. Sometimes called “The Spindle Galaxy” with its spindle-like appearance, larger scopes will reveal a distinct dustlane that splits the galaxy’s central bulge right along its axis.
So, no matter how, when or who first laid eyes on this galaxy, just know that it’s worth a look by your own eyes. Next new moon, be sure to get out and give this object a once over. It’ll be worth the look.
And as always,
Give it a go and let us know!
Good luck and great viewing!
4668
© http://messier.obspm.fr/m/ngc5866.html
4669
©HST
https://www.messier.seds.org/m/m102.html
https://www.messier.seds.org/m/m102d.html
(https://www.messier.seds.org/m/m102d.html)
NGC5866
UGC9723
Galaxy
Constellation: Draco
RA: 15 06 29.4
DEC: 55 45 48
Class: SA0+sp
Size: 6.4’x2.8’
Mag: 9.9
My choice for this week’s object came as a surprise when I realized that it had never been chosen as an OOTW! M102 is not just a delight in the eyepiece in a wide variety of instruments, but it comes with some mystery as well.
Per Seds.org, M102 was “probably” discovered by French astronomers Pierre Méchain and/or by Charles Messier in 1781. In short, Méchain recorded observing M102 (NGC5866) in late March or early April of 1781. Charles Messier included the observation by Méchain in his catalog but failed to include the coordinates, nor confirming the observation, leaving some to question exactly which object was observed by Méchain. None of this was out of the ordinary as Méchain and Messier collaborated on many of the objects that would eventually be listed in Messier’s catalog. In 1783, Méchain in a letter to then Astronomer Royal of Berlin Johann III Bernoulli, disavowed his observation of M102 stating that his observation was in fact a duplication of M101 as well as an error in his star chart.
Descriptors used at the time point to M102 not being a duplicate observation of M101. Méchain described M101 differently from M102. M101 was described as a Nebula without stars, very obscure and pretty large, between 6' and 7' in diameter, between the left hand of Bootes and the tail of Ursa Major. Difficult to distinguish when graticule lit whereas M102 was described as Nebula between the stars Omicron Bootis and Iota Draconis: it is very faint, near it is a star of 6th magnitude.
Star positions were also called into question. Whether it was Mechain’s own star designation or the possibility that there was a misprint in the star catalog he was using at the time is up for debate but the most likely scenario was the latter rather than the former.
To add more drama, Herschel “independently” discovered this object in 1788! So, who knows what’s going on?! :D:thinking:
Most probable is that M102 is in fact NGC5866. Either way, the story continues and leaves for some interesting reading material for anyone interested in coming up with their own conclusions. If you look at this link (https://www.messier.seds.org/more/m102d_more.html), you’ll see many people have differing opinions on the matter! And please feel free to read up on the fascinating history of this object here (https://www.messier.seds.org/m/m102d.html). I’m sure Steve Gottlieb with his vastly more knowledge than myself can add even more to this interesting story.
Visually, who hasn’t seen M102?! It’s a beautifully stunning object in all sizes of telescopes – even showing itself in binoculars from dark sites. M102 reveals itself as a bright, elongated NW-SE nearly edge-on galaxy. Sometimes called “The Spindle Galaxy” with its spindle-like appearance, larger scopes will reveal a distinct dustlane that splits the galaxy’s central bulge right along its axis.
So, no matter how, when or who first laid eyes on this galaxy, just know that it’s worth a look by your own eyes. Next new moon, be sure to get out and give this object a once over. It’ll be worth the look.
And as always,
Give it a go and let us know!
Good luck and great viewing!
4668
© http://messier.obspm.fr/m/ngc5866.html
4669
©HST
https://www.messier.seds.org/m/m102.html
https://www.messier.seds.org/m/m102d.html
(https://www.messier.seds.org/m/m102d.html)