There is real joy when the pleasant spring weather sets in, providing evenings of cool temperatures that I can tolerate with only a light jacket but the bugs cannot. Our garden spotlight softly illuminates the beautiful azalea newly flush with coral colored blossoms and the nearby deep purple irises. The distinctive clink of an aluminum bat connecting with a pitch let's me know that nearby Towson University is having a game this evening. Well, that and their stadium lights lighting up the tippy top of the trees in the field behind my house is also a dead giveaway.
After setting up the scope I minimize what light pollution that I can by turning off the yard lights. This evening I'm hunting Crow - some celestial highlights of Corvus as he wings his way towards a midnight rendezvous with the meridian. As my night vision slowly improves I struggle a bit to discern the outline, a geometric pattern of half a dozen 2nd-4th magnitude stars.
The first stop is an eye-catching asterism known as the Stargate. Lying roughly a degree southwest of M104, there is a good chance you may have already stumbled upon it when looking for the Sombrero galaxy. One could probably sweep it up in a star hop by extending a line from k Virginis and Spica westward about 12°, but I take the easy way out and key in the coordinates. At times with a computerized mount you feel like Picard on the Enterprise, barking out the location and issuing a "make it so!" pronouncement.
At low power in the 10" Newtonian it is delightful - a triangle of stars within a triangle, each having one of the triad much fainter than the other two. Not really seeing any color here but the arrangement is very cool. A little higher power makes it easier to see the fainter members of each of the dual triangles. So what the heck is a "stargate"? Well, near as I can tell, this is a reference to the spaceship portal used in the 80's sci-fi series Buck Rogers in the 25th Century. Hey - if the Greeks can fashion a crow from a trapezoid on a stilt then a "stargate" ain't half bad!
From an easy asterism I go in search of my next objective - planetary nebula NGC 4361, an entry in the Herschel 400 list. If you can see the top of Corvus' trapezoid it would likely be fairly easy to target this with a Telrad. However, the scope is well-aligned so I succumb to the GoTo siren and ask it to do the work for me. I inspect the field at 25mm without any filter, but there's no sign of anything unusual in the eyepiece. Adding the Lumicon UHC and studying the area once more leads me to believe that there is a faint dab of light when using averted vision. Taking the magnification up to 95x with the 16mm + UHC filter darkens the background a bit more and makes me far more certain that I’ve got this 11th magnitude planetary. I use my makeshift drape/balaclava to block out extraneous light in hopes of getting a better look and maybe even catch the central star which is an incredibly hot Wolf-Rayet star, checking in at 270,000° Kelvin (compared to our Sun at about 5,700° K). While I can see the glowing orb a little better it fails to tease out the nebula's progenitor. The nebula appears circular and fairly evenly illuminated, perhaps twice the size of Jupiter. While given the moniker of "The Water Sprinkler" based on images of it that show internal detail, in my scope I discern a faint, glowing orb best seen with averted vision and lacking any structure. The field it is set in is very sparse, made more so due to the use of the UHC filter.
Next in my Corvian exploration is S1604 (Struve catalog entry #1604), one of the targets listed in the AL's Double Star program. This double is not in a very friendly star-hopping location with multiple other similar stars near it and no solid anchor point to start from. It isn't listed among the keypad’s roster of double stars, so I do a quick lookup of the RA and Dec and key the coordinates. Having expended the effort at the outset of the session to get a good alignment pays dividends as the scope dutifully moves to the spot. Looking over the field at 25mm there are a couple of candidate suns that may be the target, and I think I see one of them as a double. Bringing the magnification up to 156x and revisiting each one I quickly confirm the right one. S1604 reveals itself as a splendid triple system that closely replicates a right angle. The two comes are very close in magnitude with the brighter one making a N-S alignment (PA ~0°) and the other E-W (PA ~90°) with the primary. This is curious, as Burnham's Celestial Handbook lists the position angles as 91° and 73°, clearly at odds with what I am seeing (and what is listed in the AL Double Star program list). Why the difference - is it an errata in Burnham's? I find it hard to accept that the stars changed position that much (especially given one of them is believed to be an optical alignment rather than a true common pair). Not sure that I am picking up any color here, although the faintest of the trio might have a ruddier glow to it.
Saving the most challenging for last, I set off for the Antennae galaxies - NGC 4038 and 4039. This duo of roughly 10th magnitude interacting galaxies should be doable in a 10" telescope, but the challenge becomes plucking them out from the bad light pollution. While the GoTo had been doing very well, for this item I decided to use my star hopping skills to have certainty that I was over the target. Locating TY Crv lying west and midway between g and e Corvi, I nudge the scope northeast until I encounter the 8½ and 9½ magnitude pair of SAO 157047 157046. From there it’s almost due north to HD 104496 and SAO 157048 where the galaxies should be found more or less midway between these two stars. I navigate the route with a high degree of confidence, reaching the endpoint and earnestly scanning the eyepiece field. Alas, there is nothing there to greet me. I check carefully with the 16mm and then the 9.7mm eyepiece, and then repeat the process using the Baader Moon & Skyglow filter. I even grab the balaclava once more to shield my eyes from extraneous light, but there is simply nothing to be had. Perhaps another, clearer evening, or waiting to try in early morning hours next winter, would bear fruit. Sadly the light pollution wins this round.
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| Star hopping to the Antennae |
It's been a very satisfying evening under the stars with my feathered friend. While I'm tempted to continue looking for other spring objects in the area I decide to pack things up since I'll need to be at work in the morning. And that is part of the beauty of our hobby, the heavens (usually) will offer you another opportunity to explore its wonders, even amid suburban skies.
