A mini messier marathon & a hop through the Virgo galaxy

by Jason Hatton

I had a nice short deepsky observing session last night (Wednesday evening 27-28th March 2003) from the backyard which I thought might be worth sharing with everyone. Transparency was quite good, but poor seeing & wind precluded any serious planetary observing, which is what I would normally do using my G9.25. So instead I decided to do some deep sky observing using my old 6" newtonian which hadn't been used in a few months. It was nice to return to the simplicity of this scope & the pleasure of star hoping at low power.

Orion was low in west so I aimed for M42, which appeared as a nice fan shaped patch of light at low power (x28.5) with trapezium at it heart. Poor seeing low down was quite obvious, so the Trapezium was not fully resolved. A quick star hop lead to M78, visible as a faint patch of light surrounding two dim stars.

Jupiter was high up close to the meridian. In the 9x50 finder the Beehive cluster (M44) was in the center of the field of view with Jupiter lying along its southern edge. At x28.5 in the scope the two equatorial belts were obvious & two moons were visible on either side of the planet. It was possible to fit almost all of the beehive into the field of view along with Jupiter, a nice perspective. Having spent the last several weeks observing the ever changing cloudtops of Jupiter at high power, it was interesting see the entire Jupiter & the galilean moons floating in front of this pretty starfield - Space is a big place!!!!

Auriga was getting low in the west so I took a quick peek at M37, which appears as a very rich condensed cluster in the 6" at low power, always a nice sight in this instrument. Unfortunately M36 & M38 were just out of view behind the branches of the garden's trees. However, Gemini was still high up enough for viewing, so I quickly looked at M35 in binoculars. The Eskimo nebula (NGC-2392) was quickly located at low power, being obvious as an out of focus star that blinked out when looked at directly. At x73 the planetary nebula appeared as a small disk.

Leo was high up in the south east. Unfortunately light pollution is more of a problem in this part of the sky (looking towards the city), but this didn't stop me from locating several galaxies. The majority of the galaxies viewed appeared as rather featureless faint patches of light, although in some cases it was possible to identify the morphology either a spherical patch of light for eliptical galaxies or an elongated smudge for spirals. Most galaxy observing was done at x41 to darken the sky & improve contrast. NGC-2903 was easy, appearing as relatively large elongated patch of light with a bright nucleus. moving further into Leo, M65 & M66 were visible in the same field of view with the major axis of the galaxies discernible. However, NGC-3628 wasn't readily visible probably because its surface brightness was too weak to overcome the sky glow. M-95 & M-96 were easy to spot in the same field of view, (although more widely seperated than M-65 & M-66) with M-96 being distinctly brighter. A little to the north of this pair M-105 was visible, with the nucleus of NGC-3384 very close to M-105's nucleus - this gave the appearance of a double galaxy.

Starting from Denebola I star hopped into the heart of the Virgo cluster. Using Uranometra I jumped from one galaxy to another starting from M98 & M99, making a great loop through the galaxy cluster before returning to the start point. On the way I saw M100, M84 & M86 (in the same field of view), M87, M90, M58, M91 & M88. M87 appeared as small globe of light, somewhat brighter than most of the other galaxies, but nevertheless quite faint. M-59 was not seen, although this part of the sky was much deeper into the light pollution dome of San Francisco & the east bay.

One of the nice things about astronomy is the diversity of things that you can do. Although I've become very focussed on planetary imaging & observing, it is always good to occasionally do something different such as hunting down faint galaxies at the limit of the telescope & sky conditions, or just scanning the summer Milky Way with the naked eye or binoculars. One thing is certain it will be a long time before I run out of things to look for or new observing projects :-)

Jamie Dillon wrote:

What I want to know is where do you live? Catching a scad of Virgo galaxies from home in a 6", you have some decent transparency. From Salinas in an 11" they're just not home (hafta keep onto that problem from a couple of angles).

I'm observing from southern Marin, a few miles north of the Golden Gate bridge. Yes, the sky is much darker here than most places I've lived, although there is still enough light pollution that haze can brightnen up the sky quite a lot. Since Mount Tamalpais is to the west & the bay to the east, there is only local light pollution to deal with. The brightest part of the sky is to the east & south east (towards San Francisco & the east bay) & the darkest to the west.

On a good night M33 is an easy binocular object & M31 naked eye. Observing las t autumn with the G9.25 & a UHC filter I could see a lot of detail in the Veil Nebula & even without the filter the brightest parts were detectible. The 6" showed the entire nebula using a UHC filter, but it wasn't detectible in this instrument without the filter.

A few months ago I did a comparison between my observing site & that of a friend in San Francisco, which showed that even with significant light pollution it is possible to observe many deep sky objects when transparency is good. Using my G9.25 in Marin I observed the main galaxies around the great square of Pegasus. Most of these galaxies could be seen well enough to show morphology - the basic shape of the galaxy & the nucleus. Observing from the Sunset district in San Francisco, under conditions of good transparency, using a 10" SCT it was possible to observe much the same structure in these galaxies, although it was much more difficult to pick up some of the fainter galaxies in proximity to the main galaxies. Often it is possible to use modera te magnifications on galaxies to reduce sky glow, especially if the galaxy has a reasonable surface brightness. We also looked for the Veil Nebula using the 10" & a UHC filter. This was much tricker to see than it was in my G9.25 from Marin, although it was still nevertheless possible to faintly trace the brighter parts.

I hope everyone had a good time observing last night & the night before. Seeing was excellent last night, so I concentrated on observing & imaging Jupiter. A lot of fine detail is apparent on the planet under good conditions. Both the south equatorial belt (SEB) & north equatorial belt (NEB) have a lot of structure. Last night there were a couple of dark festoons on the southern edge of the the NEB, & some fine detail in the equatorial zone. A segment of the N. Temperature belt was also apparent.

Tonight (March 30, 2003) the great red spot (GRS) will transit Jupiter's central meridian around 22:00 local time. Currently the GRS is becoming more prominent, appearing a weak almon pink in color. The part of the SEB following the GRS is very turbulent & the structure of this changes over very short time scales. Right now the part of the S. Temperate belt close to the GRS is very dark which nicely frames the spot & there are some white ovals in the S. temperate region, but these are quite trick to see. Seeing might be good again tonight, so Jupiter will be well worth a look.