Here is the saga of trying for Hoag’s Object – so far! Start at the bottom and work up for the story in date order.
2017 May 2
After several hours observing Arp Atlas objects I switched to the field of Hoag’s Object at about 2.15 a.m. UT. Hoag’s was about 45 degrees past the meridian at an altitude of about 54 degrees. In the 8mm Ethos x260 I could see the 15.0 magnitude star which sits just south of Hoag’s Object, clearly. On and off, I wondered if I could make out a tiny round smudge where the galaxy should be, but with no certainty at all. Surely I should see a more or less stellar nucleus, not something of any size? I then switched to a 5mm Clave Plossl giving x410. I struggled to relocate the correct field in this much tighter eyepiece. By now heavy dewing was getting into everything, so I quit.
2016 March 17
Spring is here again and it’s time for another try at finding Hoag’s Object, the rare ring galaxy in Serpens. Sources usually give its brightness as “16th magnitude”, though I have seen some which say it is as bright as 15.0m. I don’t expect to see the ring but surely the core ought to be within range.
Damian Peach has done a picture of it; take a look at it at the bottom of this long webpage:
I tried to spot Hoag’s Object in both 2014 and 2015, without success. In the early hours of 2016 March 17 I tried again. This time I warmed up on Arp 64 which lies nearby in neighbouring Boötes. I found Arp 64 easily enough; it is 15.1m and 1.4 x 0.4 arc minutes in size. In the same field of view is a fainter galaxy, MCG+3-38-6 which is 15.4 and 0.4 x 0.4 arc minutes. Strangely, I could see this one more easily than I could Arp 64.
Seeing MCG+3-38-6 was very encouraging because the core of Hoag’s Object is a similar size, 0.3 x 0.3 arc minutes. Sadly, again I failed to see any trace of Hoag’s Object. I’m not giving up yet – I need one of those rare “5 by 5” nights when the atmosphere seemingly disappears. Extra magnification might also help but I can’t justify £450 for a 6mm Tele Vue Ethos!
2015 April 15
Object: Hoag’s Object
Date: 2015 April 15
|Peculiarity: Ring galaxy presented face on.
|Time & altitude: 01.00 UT 59º
|Seeing (5 high): 3/5
|R.A: 15h 17m
|Transparency (5 high): 4/5
|Dec: +21º 35
|Telescope: 0.5m f4.5 Dob.
|Eyepiece: 8mm Ethos x260
Size: 6” inner core.
45” outer diam.
Not successful despite half decent conditions and using all the usual dodges. I followed the field for 90 minutes up to 01.00 UT as it gained altitude from 50º to 59º (altitude at transit is 60º). I readily saw all the stars on the Megastar chart reproduced below so my limiting magnitude must have been around 15½. As consolation, a meteor crossed the field leaving a turbulent orange train which swiftly dissipated.
2014 May 2
Looked at the field of Hoag’s Object at intervals between 21.00 UT and 00.15 UT when cloud stopped play. It would have reached the meridian and maximum altitude at around 01.30UT. Sky transparency was better than average, not exceptional.
Using the Halton Arp Telescope, a borrowed 13mm Ethos eyepiece (x160), my 10mm Clavé Plossl (x205), both oculars used with and without a Lumicon deep-sky filter. The limiting magnitude performance of the two eyepieces was similar, impossible to say one showed more than the other.
All stars plotted in Megastar 5 in the vicinity of the galaxy were seen. The faintest stars did not show themselves until the altitude increased. A star 3.5’ N of Hoag not plotted on Megastar but appearing in CCD images was also seen.
Hoag’s Object was not seen at all for most of the session. As the field gained altitude, I fancied it barely detectable from about 23.30 UT onward; more suspected than seen, only ever in AV and once in any five or six minute period. Not enough for me to say I’ve seen it.
Sidgwick’s Amateur Astronomer’s Handbook page 5 puts the practical limiting magnitude of a 50cm aperture at 16.2. The mirror coatings are 9 years old and the previous owners for the telescope’s first six years did not use mirror covers. I am having the mirrors re-coated in this summer’s recess.
2013 August 3
There was a write-up about Hoag’s Object in the June 2013 BAA Journal, page 165. It said visual observing is “problematic”. Problem accepted!
I tried for it on the evening of 3 August. The first thing that struck me is that the field is an easy star hop to find from Epsilon Boo. It’s always good to be sure you’re looking in the right place. Annoyingly it clouded up and by the time the clouds departed around midnight the field was lower and moving into the light spill over Canterbury.
I didn’t detect anything, no suggestion of the nucleus. I was using the half-metre Dobsonian with my favourite combination of 10mm Clave and Lumicon deep sky filter. Hardy surprising as I suspect a positive identification will depend on ideal conditions. May is probably a better bet than August, so I will try again then.