Alan Whitman's 2004 Messier Marathon

The local Penticton, British Columbia club had a Messier Marathon planned

for Saturday, but Friday's satellite images convinced me that I should take

advantage of Friday's crystalline skies instead -- Saturday looked poor (as

it turned out to be). I chose my marathon observing site four years ago

after driving hundreds of kilometres of Okanagan Valley back roads because

it has the best horizons that I can find: treeless fall-away horizons to

the south and west and a slight upslope to about 4 degrees altitude to the

east. (You can't drive the unplowed road to the peak of Mt. Kobau before

June.) My site is at 4000 feet on Anarchist Mountain (actually a plateau),

is less than a mile north of the 49th parallel (the US border), and is on a

gravel country road leading to a farming community, Sidley Mountain Road.

Fenced fields prevent you from setting up off the road, but traffic is

normally light, especially after about 9:30 PM. (More traffic on Friday

evening than on any other evening that I have been there, though -- not

surprisingly. Friendly folk -- many stop with their lights on and want to

chat, including someone just as I had started starhopping to M74 -- just

great for critical dark-adaption -- hope that he didn't mind me conversing

with my back turned to him and my hands over my eyes ! Most of them do

drive by very slowly so as not to raise dust, or perhaps to see whether you

are a weirdo-threat.)

I used the club's 8-inch f/6 Skywatcher Dob at 60x (an old Meade 20mm

Erfle), my 7x50 binoculars, and my unaided eyes -- whatever was fastest for

each Messier.

At the beginning there was a persistent 4-degree wide band of cloud in the

west. Fortunately it turned out to be just above M77 and M74, but it

complicated the starhop down to those two. Got M77 first, then a ghostly

but definite M74 (to my surprise), and all of the evening Messiers. Getting

all of the evening objects was a first for me, but this was nine days

earlier than I've ever done a Messier Marathon before and the transparency

was excellent. The zodiacal light was very bright. Seeing was good, based

on views of Jupiter around midnight.

Got the first straight 102 objects although I wasn't very efficient. This

was my first marathon in four years and there are MANY Messiers that I

haven't viewed since the last marathon. So I lingered for a minute or more

over many of them instead of moving on promptly as one should. On M83 I

raised the power to 93x and had by far my best 8-inch view of this galaxy:

I glimpsed not only the central bar, but also one of the two southern

spiral arms. (Seeing this detail with the 8-inch is probably a result of

knowing what to look for, having viewed M83 in Australia from whence all

three arms were visible with a 14.5-inch Dob.) Earlier I had lingered too

long over M101 at about 60 degrees altitude -- at 93x it showed a fairly

faint nucleus, two barely discernable spiral arms, and several knots.

All of these overlong looks added up to the loss of my normal 1 AM nap when

marathoning -- I had frittered away my extra time. I had little sleep the

previous night and haven't done an all-nighter in three years. But I

needn't have worried about keeping awake -- the temperature of -7 degrees

Celsius and a breeze kept me wide-awake. There is always a downslope

drainage wind at this site from the north-east and I have never had any

problem with eyepieces or finders dewing (frosting) up.

About 2AM persistent thick cloud appeared on the southern to SSE horizon,

solid to an altitude of about 4 degrees with some bands for a couple of

more degrees above that. This was worrying, because M69, M70, M54, and M75

don't get any higher than an altitude of 4 degrees at this latitude until

about 20 minutes after twilight begins.

I had to delay going after M19 and low M62 until a thin spot came along.

The 7x50s found M6 in a narrow clear band between the dense cloud on the

south horizon and the next cirrus streak above. But I had a heck of a time

with M7 which was buried behind the dense cloud. The 7x50s finally got the

bright cluster through a thin spot, but this repeated sweeping along the

horizon looking for a fortuitous hole was very time-consuming and it was

after the beginning of astronomical twilight (AT) before M7 finally peeked

through.

M2 was the last object that I logged, seven minutes after AT when it had

risen 2 degrees above the lowest dip on my site's eastern horizon. (It

would have been 5.6 degrees above a flat horizon.)

Since M69, M70, and M54 were buried in cloud, and M75 was either buried or

perhaps in cirrus at best, my only remaining possible targets were M72 and

M73. (At this latitude, 10 minutes after AT M69 has risen to only 3.1

degrees compared to 19 degrees at AT in southern Arizona, the proper place

to do a Messier Marathon. M30 is not visible during marathon season from

this latitude and M55 doesn't become possible here until about April 8th.)

The hassle with M7 had made me several minutes late in starting the starhop

from Enif and Alpha Equulei down to M2 (visible in the finder) and so the

twilight was too advanced by the time that I starhopped to faint M72. I

"suspected" M72 but didn't count it. I also logged M73 as only "suspected"

because I only glimpsed two stars, not the expected Y-shape of four stars.

Thirty hours later I realized that since magnitude 3.8 Epsilon Aqr was

fading from naked-eye visibility at the start of the starhop, there was no

way that I should have expected to see the two fainter stars in M73 at

low-power in bright twilight. So I now believe that the pair of stars that

I glimpsed were indeed the two brightest stars in M73. That brings my score

up to 103, compared to my best score of 105 set April 8/9, 2000 (that year

moonlit Cirrus clouds cost me M33).

If it hadn't been for the cloud to the south obscuring the four Sagittarius

globulars, I MIGHT have managed a score of 106? That cloud finally moved on

about 30 minutes after AT and I went after M54 then, but the sky was far

too bright. While sweeping for the globular I repeatedly glimpsed a fuzzy

in the eyepiece, but it was very elongated rather than round -- perhaps a

cirrus patch faintly illuminated by the sun?

So I missed seven Messiers, four of them due to the thick cloud on the

southern horizon from 2AM until about 4:40 AM. I checked several hours of

satellite images after I returned home and was able to identify the thick

patch of cirrostratus from its motion -- it was located over the

southernmost fifth of Washington State ! The northern edge of that patch

was about 180 miles south of my observing site. As Guy Mackie, one of my

clubmates, commented, "That's marathoning."

Increasing cirrus streaks were showing up elsewhere in the sky by 5AM and

by the time that I got home at 7AM Saturday we had overcast cirrostratus.

If we get a chance on Monday or Tuesday I'm going to try again to improve

on my 2000 score of 105 -- I was very rusty Saturday morning after not

marathoning for four years. I'm convinced that 106 is possible from

latitude 49 degrees North on a cloudless night. But some March I'm going to

do it right from Arizona where only M74 and M30 would be at all challenging.

At 8 PM Monday evening the moon will be mag -7.5, at 4 degrees altitude,

and sets at 8:31 PM which is 30 minutes after AT ends. The moon is only 6.9

degrees below M74 and 17 degrees from M77. I don't know whether the moon

will kill any chance for M74 -- I have never tried observing a deep-sky

object only 7 degrees away from a 2.4-day-old moon. The main problem with

M74 is the bright zodiacal light and that unavoidable problem MAY be much

more of a problem than scattered light from a mag -7.5 lunar crescent IF

the transparency is superb on Monday evening as it should be since British

Columbia will be just behind a Pacific cold front. Has anyone succeeded

with M74 that close (7 degrees) to a 2.4-day-old moon?

Best,

Alan Whitman

Penticton, British Columbia