ETX-125 OBSERVATIONS FOR APRIL 2005



ETX-125 OBSERVATIONS FOR APRIL AND MAY 2005.

I have been able to piece together nine viewing sessions involving new material for this period. All sessions were conducted from my rear garden in Bury, Lancashire, England (11 miles from Manchester, moderate light pollution). All times quoted UT first, with local time in brackets.

Eyepieces used throughout all sessions were:

Low power = 40mm Meade Series 4000 Super Plossl (48x)

Standard power = 26 mm Meade Series 4000 Super Plossl (73x)

High power = above plus 2x Meade barlow (146x), or 11mm TeleVue Plossl (173x)

Maximum power = 11 mmTeleVue Plossl plus 2x Meade barlow (345x).

Standard power was used throughout all sessions unless otherwise noted, generally for viewing planets or double stars.

April 21, 2005

Conditions: hazy, calm, seeing 7, ZLM 4.0

Time (UT): 21:00 - 22:20

This was only a short session, due to the near-full Moon.

21:00 (22:00) Aligned ETX on Regulus and Capella.

21:05 (22:05) I checked the brightness of a couple of variables. R UMa was continuing to fade to 8.5, but R Leo was continuing in the opposite direction and had risen to 7.6.

21:15 (22:15) The Moon was becoming very bright, requiring me to use a filter. Many familiar features were drowned out by the Tycho rays, but there were two fine objects on the terminator, the huge walled plain of Schickard, and the unusual ‘filled plateau’ of Wargentin, both impressive at high power.

21:35 (22:35) The rest of the session was casual, and included views of Jupiter and the more showy spring doubles, especially Gamma Leo, Zeta Cnc, Mizar, Cor Caroli and a descending Castor.

22:20 (23:20) Parked the scope.

April 29-30, 2005

Conditions: clear hazy, light S breeze, seeing 8, ZLM 4.8

Time (UT): 21:30- 23:25

This was a better night than recently, though with high cirrus often compromising the view.

21:30 (22:30) Aligned the ETX on Regulus and Capella.

21:35 (22:35) I checked up on R Leonis, and it had brightened again to 7.2, but R Ursae Majoris had declined a little again to 8.7. I also took a first look at another spring variable, S Virginis, which was quite faint at about 10.6. Another variable attracting my attention was Y Canum Ven, famous for its striking red hue – living up to its alter ego of ‘La Superba’. To my eyes, it was as colourful as Mu Cephei, Herschel’s Garnet Star.

21:50 (22:50) It was time to take a quick look at Jupiter. Io and Callisto were east of the planet, whilst Ganymede and Europa were to the west, the former being quite close to the Jovian limb. I also spotted a broadening ‘knot’ in the North Equatorial Belt and hints of ovals but the Great Red Spot was out of view.

21:55 (22:55) I slewed the ETX south to complete my study of doubles in Hydra. Its vast length was brought home by the fact that I had studied the Water Snake’s ‘head’ three months ago, but only now had the ‘tail’ come into view, very low east of south ! I’d never had a chance to spy out the many galaxies in the group, which was a pity, since the brightest of them, M83, would have been a conspicuous object in the ETX if it hadn’t been so far south.

The three doubles seen tonight were the white pairs of HN69 and h4606, plus the white / yellowish pair of 54 Hya. All three were easy at medium power.

22:20 (23:20) I returned to Jupiter, and Ganymede was by now very close to Jupiter’s limb, so I kept the ETX trained there to see the occultation of the satellite over the next ten minutes.

FILL YOUR BOÖTES !

22:35 (23:35) I had now almost reached ‘full circle’ in the sky since I’d bought the ETX, as I began a double star survey of ‘old friends’ in Boötes, which saw first light in the scope way back last August.

The yellow pair of STF 1785 and the white one of STF 1793 were clearly split at high power, but showed little colour. STF 1825 showed more of a colour contrast, with yellow and orange components.

Kappa and Pi were both nice white and bluish pairs, seen best at medium power. Iota was wider than the previous two, but still showed a nice yellow and blue colour contrast.

Tougher again were STF 1834, which was hard for me to see at maximum power, as it was almost on the zenith. The same power showed Zeta only as slightly elongated, without a clean split.

Three other pairs were easy at medium power; the all-white STF 1835, the vageuly yellowish and evenly-matched STF 1838, and the all-white STF 1850.

CHECK THE SCALES !

23:05 (00:05) I then slewed the ETX south for first light on the dull Zodiacal group of Libra, but the first port of call was a minor planet passing through the constellation. I found Ceres forming a kite on its side with three fainter stars, the one to its south obviously reddish in hue.

I took a low-power look at the wide white double of SHJ 179, and would have carried on in Libra, but the sky was clouding over from the south.

23:20 (00:20) I thus dodged the clouds and pointed the ETX back north to Boötes with feelgood looks at Xi and Epsilon (Izar). Izar was glorious at maximum power, with yellow and blue components both surrounded by crisp diffraction rings. Xi was also fine at high, with contrasting colours of yellow and magenta.

23:25 (00:25) I parked the scope and ended the session once Izar went behind cloud. I had to leave the rest of Boötes and Libra for another night.

May 4, 2005

Conditions: a clear spell with occasional high cirrus cloud, moderate N breeze, seeing 6, ZLM 4.7 to 4.9

Time (UT): 21:30- 23:00

This session was mostly a time for re-visiting, but also included some forgotten deep-sky targets, missed in previous weeks.

21:30 UT (22:30 local) Aligned ETX on Arcturus and Regulus, and took a casual look at some brighter doubles.

21:50 UT (22:50 local) The ETX had cooled down enough for a peek at Jupiter’s moons, with an occultation of Io in the offing. Europa was east of the planet, with Ganymede and Callisto due west. Io was also west of the planet, but very close to the limb. I kept the ETX pointed there to see Io occulted over the next ten minutes.

22:00 (23:00) The sky had darkened enough to revisit a variety of Messier galaxies in Canes Venatici (M51, M63, M94) and Leo (M65, M66), discussed in detail in earlier reports.

22:20 (23:20) I had the opportunity to pick up two rare deep-sky objects in Boötes, a group better known for its numerous colourful doubles.

The galaxy NGC 5248 was a faint oval patch, south of a ‘Delphinus diamond’ of 10th mag stars, needing averted vision to confirm it. The globular NGC 5466 was another elusive object, just detected to the west of a yellow 7th-magnitude star in a sparse field.

22:35 (23:35) I also realised that I had forgotten some galaxies and an errant globular in the eastern part of Virgo, so I made an attempt to log them.

Globular NGC 5634 was easier than NGC 5466, visible in direct vision west of an 8th mag field star. I did not hold out much hope for the galaxies NGC 5068 and NGC 5247, as they were both well to the south. In the event, I could not make them out due to horizon haze, with the star fields barely seen as well.

Galaxy NGC 5317 was barely seen in averted vision, forming a large near-right triangle with two field stars to its northeast.

Galaxy NGC 5846 was just seen in direct vision, forming a small right-angled triangle with two dim stars to its northeast.

22:55 (23:55) Increasing cirrus cloud was beginning to dim the fainter stars, so I took a last feelgood glimpse of Jupiter.

23:00 (00:00) Church clock in distance striking midnight, time to park the ETX.

May 7-8, 2005

Conditions: clear spells with risk of showers, fresh NW wind, seeing 7 improving to 8, ZLM 5.0

Time (UT): 2150 – 00.40 next day

SPRINGING INTO SUMMER

21.50 UT (22:50 local) Aligned the ETX on Arcturus and Regulus, followed by a casual revisit of a variety of galaxies in Coma and Virgo.

22.30 (23:30) I felt a feeble rain shower in the air, so I parked the ETX and took it indoors.

23.15 (00:15) That was only a short shower, so as soon as the sky cleared, I realigned the ETX, again on Arcturus and Regulus. I dodged the clouds to revisit the faint galaxy NGC 5248 and globular NGC 5466 in Boötes, and found them slightly easier than I did three nights ago, as they were evident in direct vision.

I then continued my Libra tour (postponed from April 30) with a look at more doubles, plus a faint globular in the same group.

Mu was a tough white pair, barely seen at high power, vying with Iota Leo for difficulty.

HN28 was a much easier orange and red pair, nice at low power.

Iota was a white pair, wide but with a faint companion.

Omicron was again wide but more evenly matched.

STF 1962 was a nice well-matched yellow pair.

The only deep-sky object in Libra within range of the ETX was the globular NGC 5897, and I could only see it with difficulty using averted vision, as the lower left member of a ‘beehive’ or ‘Cepheus’ of faint field stars.

Before leaving Libra, I took a look at Beta, said to be the only green naked-eye star. I must confess that it looked white to me, both with and without the telescope. The only green stars I can say I’d seen were companions to red primary doubles such as Alpha Herculis (Ras Algethi), and the green colour was due to contrast effects.

I also revisited the galaxy M108 and the Owl Nebula M97 in Ursa Major.

ORION’S BANE IS RISING !

23:50 (00:50) I realised that there was only one major constellation in the British sky left for me to study from scratch (or should I say sting) in the ETX. Orion had long disappeared into the twilight, but his lethal enemy, the Scorpion, was now rearing up low in the southeast.

As an aside, it really pains me that I cannot see Scorpius properly from Northern England, with parts of it permanently below the horizon. The first time that I saw the complete figure, sting and all, was four years ago on vacation in southern Portugal, and I was suitably impressed. I had my 20 x 80 binoculars with me and was rewarded with enjoyable views of M6, the Butterfly Cluster, and Ptolemy’s Cluster, M7.

I therefore had to make the best of my latitude handicap to seek out some doubles and a couple of globulars in the northern parts of the Scorpion, even though I felt it to be a scant reward.

Nu was a nice white pair, very wide, best seen at low power

Beta was a bright white and blue pair, striking at medium power.

Xi was a fine white and yellowish pair well seen at medium, with the slightly wider yellow pair of STF 1999 in the same field, forming an intriguing ‘double-double’.

After those doubles, I aimed the ETX at the globular M80, which was small but fairly bright, and hence easy to see despite its low altitude. Scorpius’ other Messier globular, M4, was still hidden behind houses, so I took a feelgood look at globulars M3, M13 and M5. The last-named was a grand sight at high power, with many outlying stars seen, and hints of resolution in the middle distance.

00.30 (01:30) Antares and the M4 area had now come into view, so I began with a look at Sigma Sco. I split it into its white and bluish easily despite the low altitude and the large difference in magnitude, and so I then tried to find M4 but fail. The haze must have increased in the last few minutes, or was M4 a low surface brightness object compared to M80 ?

00.35 (01:35) I then made a foolhardy attempt to split Antares at 7° up ! All I got in the ETX was horrible false colour and no sign of any companion. The light pollution filter did show a spurious green companion, but that was only a refraction effect.

00.45 (01:45) Rain had been building up in the air those last few minutes, and I felt the drops on my face. It had the makings of a heavier shower than last time, so it was time to disconnect everything without parking the scope. The ETX was back indoors in ten seconds !

May 8-9, 2005

Conditions: clear , light NW wind, seeing 7 improving to 8, ZLM 5.1

Time (UT): 21.35 – 01.00 next day

This was a good all-round viewing night, being moonless and clear.

21.35 (22:35) Aligned the ETX on Arcturus and Regulus.

POLAR DOUBLE TIME

21:40 (22:40) I spotted the winding sprawl of Draco dominating the high northern sky, surrounding Ursa Minor, and decided to pay a revisit of the best doubles last seen in October, plus a collection of new ones.

In Draco, my revisits took in the wide white pair of Nu, the Albireo clone of Omicron, the red pair of 41 Draconis, the yellow pair of Epsilon and the yellow and blue STF 2452. First-time pairs were:

STF 1362, nice equal white, best at high power

STF 1516, a fine orange pair well seen at low power, with a red field star to the east

STF 1599, a wide colourful triple well seen at low power; its southernmost being red

STF 1654, orange and yellow, best at high power

STF 2092, nice yellow / orange pair well seen at medium power

STF 2273, wide yellow pair, with red star to south, nice at low power

STF 2348 and STF 2377, both orange and white, best at low power

STF 2440, orange and yellow, fine at medium power

STF 2604, an orange pair best at low power

HU 757, orange and bluish, best at higher powers

After another look at the yellowish and lilac Polaris, I tackled the following in Ursa Minor :

STF 1972 was a wide yellow pair, nice at low power.

STF 1583 was a fainter white pair, better at medium power.

STF 1840 was white with a faint companion, well seen at medium power.

22.20 (23:20) Although the northwestern sky was still in twilight, the south was now dark enough to revisit the brighter Leo and Virgo Messier objects. I therefore took looks at M65, M66, M84, M86, M87 and M104.

22.45 (23:45) I was able to confirm the dim globular NGC 5053 in Coma, north of a triangle of bright stars in the field. In the same group, the edge-on and needle-like NGC 4565 illustrated the use of allowing build-up of photons on the retina, as the image revealed more the longer I looked !

23:10 (00:10) I continued my doubles hunt in the eastern reaches of Boötes.

STF 1884 was a tough pair, equal to Iota Leo in difficulty.

Zeta again was only visible as slightly elongated, with no hint of a proper split.

39 Boo, 44 Boo and STF 1910 were all yellowish pairs well seen at high power.

Delta was wide, yellowish and bluish, best seen at low power.

Mu was very wide, best seen at low power, but the fainter component was revealed to be itself double under high power.

BATTLING GIANTS AND SNAKES

23:40 (00:40) After looking at Boötes, it was the turn of a rather confusing area of the sky to come into view. The large and rather obscure constellation of Ophiuchus, along with his serpent, was beginning to dominate the southeastern sky, and his serpent appeared the worse for the struggle, pulled in half !

I began to tackle this area with a look at objects in the Serpent’s ‘head’, taking in five doubles and an old friend of a globular.

STF 1919 was a wide yellow pair, best seen at low power.

Beta was a wide white pair, but with a companion six magnitudes fainter than the primary, and an even fainter third member in the field.

STF 1931 was a yellowish / bluish-white pair, again well seen at low power.

STF 1985 was a yellow pair, best at medium to high power

Delta was a fine yellowish pair, best at high power.

I ended my study of Serpens Caput with a feelgood look at the fine globular M5.

00:05 (01:05) I began a tentative study of the far southern part of Ophiuchus, as it only offered a brief viewing window before the twilight season came upon me. I picked them off as they made their appearance above the houses.

Rho Ophiuchi was an interesting system, as at first sight it looked like a very wide all-white triple, forming a near-right triangle. Closer inspection of the star at the right angle revealed a white and bluish pair better seen at higher power.

00:10 (01:10) I then aimed the ETX to two rather southerly globulars in the Serpent-bearer. M9 was bright and quite distinctive, but M107 was more difficult, although it was easy to locate, as two 7th-mag stars pointed south to it. I tried the broadband filter to eliminate the worst of the skyglow, and it brought out M107 better, also doing the same for NGC 5897 in Libra. The filter dimmed the last two clusters, but also removed the light pollution, thus enhancing contrast.

00:20 (01:20) Antares was now well in view, signalling that the far southern globular of M19 was going to take its place about half an hour later in the same spot. I nailed M4 this time south of a line between Antares and Sigma, but it was difficult due to its size and low altitude – it too needed the broadband filter to improve the contrast.

I looked at M80 again, and was struck by the fact that it was easier to see than M4. That flew in the face of the published magnitudes of 7.7 for M80 and 5.4 for M4. There were two reasons for this; M4 was larger and had a lower surface brightness whereas M80 had a bright concentrated core; and M80 was 3° higher up and suffered less from extinction.

00:45 (01:45) I was able to confirm the M19 easily enough, both with and without the LP filter. It looked brighter to me than M4, despite its low altitude. (I could not study M62, 4° to its south, as houses blocked the view, and in any case Manchester’s legacy to the southern horizon would have killed the image).

00:55 (01;55) I was interrupted by the noise of a nocturnal flock of geese, and my brain made an association with another summer deep-sky showcase, now coming into view in the southeast below Aquila. The ‘Wild Duck’ cluster of M11 was making its first re-appearance in the ETX since last October, and it was just as I remembered it at high power, a gloriously rich fan-shaped aggregation with scores of individual stars detected.

01:00 (02:00) I heard a local church clock striking two. It was getting late, and so I parked the ETX.

May 10-11, 2005

Conditions: clear, calm, seeing 7 improving to 8, ZLM 5.0

Time (UT): 20.30 – 00.05 next day

This was another fruitful night, and probably the last one for faint deep-sky stuff for a couple of months, with the season of all-night twilight fast approaching at my latitude of 54° North.

There were also two Jupiter events on tonight; the closing stages of a Ganymede shadow transit and an occultation.

20:30 UT (21:30 local) Set up the ETX at twilight, only rough-aligning it until the brighter stars were easily visible.

The first look at Jupiter showed Io to the east and Callisto far to the west of the planet. Ganymede and Europa were closer west, but unusually oriented at right angles to the planet’s equatorial plane, with Ganymede slightly closer. The Great Red Spot was visible to the west of the central meridian, and Ganymede’s shadow was still clearly seen on the northwest of Jupiter’s globe.

20:45 (21:45) I took a quick glance at the 2.6 day-old Moon, where the Earthshine was prominently visible even in the dusk. The only easily recognisable craters on the sunlit crescent were Condorcet to the north of the lunar equator, and Lame to the south.

20:55 (21:55) The aspect of the Jovian system had changed after less than half an hour. Ganymede’s shadow had left the planet, and the Great Red Spot had moved westward nearer the limb. Europa was now closer to Jupiter and Ganymede further away than they were 30 minutes ago.

21:15 (22:15) The sky had darkened enough to see Megrez (the faintest Dipper star) easily with the naked eye. I thus aligned the ETX accurately on Arcturus and Regulus.

21:25 (22:25) A quick variable magnitude check showed R UMa continuing to fade to 9.3 and R Leo continuing its rise to 6.8.

21:40 (22:40) I revisited a host of doubles in Virgo, for improved views over April 2, including Phi, 84 Vir, STF 1689 and STF 1833. New doubles in the same constellation were:

STF 1560, yellow and blue, best at high power due to faint companion

STF 1635, both yellowish, in a nice field at medium power

STF 1719, a north-south aligned yellow pair, well seen at medium power

21:55 (22:55) The Corvus quadrangle was now prominent in the south, despite the northern sky still being in twilight. I revisited the doubles of Delta Crv, STF 1669 and Gamma in neighbouring Crater. I could plainly see M68 in nearby Hydra with the help of the broadband filter to remove the baleful sodium glare, and then made a half-hearted attempt to see two difficult deep-sky objects in Corvus.

Using averted vision, I suspected the planetary NGC 4361 with the broadband filter, south of an elongated downwards-pointing triangle of 9th-magnitude stars. The colliding galaxies of NGC 4038 and 4039, were likewise near-impossible in averted vision. Again it required the filter to suspect them as a single dim blob, in the same field as a trapezium of 9th magnitude stars, with the two brightest ones pointing south to it.

22:35 (23:35) I took a quick look at Saturn. The Cassini Division was now becoming less distinct at high power as the planet was descending.

22:45 (23:45) Europa was now near Jupiter’s western limb, and the Great Red Spot also close to west of planet, soon to go. Europa disappeared behind planet in occultation a few minutes later.

23:00 (00:00) I then experimented with high power to revisit a selection of eight galaxies, to see if any extra detail became visible. M104 was fainter but showed more subtle details, including a hint of its bulge, though not the dark dust lane. The edge-on arms of NGC 4565 appeared slightly easier to see, as the higher power dimmed the brighter core. M51, M94 and M63 also benefitted, with subtle gradations in brightness visible from their cores. I still could not get the ETX to bring out the Black Eye of M64 though, and elliptical galaxies such as M49 and M87 showed little or no improvement. There is no substitute for a dark rural sky when it comes to discerning detail in galaxies, no matter what the power !

A LITTLE CROWNING GLORY

23:35 (00:35) Another late spring group had by now come into view, the small but attractive semicirclet of Corona Borealis, which really did look like a ‘crown’.

After all those months of checking long-period Mira-type stars, I took a first look at two variables of a very different kind in the Crown; one famous for its surprise brightenings, the other for its shock fadings.

R Coronae was at its ‘resting’ magnitude of 6.0 and not veiled in soot, otherwise it might have been invisible in the ETX at about mag 14.

The other, T Coronae, was visible faintly at about mag 10.5, and had not brightened up to the second mag, as happened in 1866 and 1946. Perhaps I might have to wait until 2026 for this one to erupt again !

My survey of doubles in Corona included revisits from last summer, plus three new pairs. The white / blue pair of Sigma and the yellow pair of Zeta were both pretty at medium power, as was the yellowish duo of STF 1964. I also remembered how tough STF 1932 was, and again, maximum power was needed for that one. Eta might have been splittable in 1993, but now it appeared stubbornly single in the ETX – I would have to wait until 2035 for the next attempt. The three new doubles in Corona were:

STF 1950, reddish and yellow, nice at high power (catalogued in the Eagle Creek list as being in Corona, but seemingly ‘migrated’ to Serpens Caput according to SkyMap software ! )

STF 1963, yellowish and bluish, again well seen at high power

STF 2044, orange and bluish, best at medium power

23:55 (00:55) I ended the evening’s viewing with feelgood looks at globulars M3 and M13.

00:05 (01:05) Parked the scope

May 12, 2005

Conditions: high cirrus cloud, calm, seeing 6, ZLM 4.5 (best)

Time (UT): 20:40 – 23:15

Rough-aligned the ETX to study the 4.6 day-old Moon and satellite events on Jupiter.

The session was limited to a few quick looks throughout the evening, as there was too much high cloud around to view any other targets. The main event tonight was a double Jovian satellite transit, involving Io and Europa.

20:45 UT (21:45 local) Slewed the ETX to Jupiter. Io was close to Jupiter’s limb, east of the planet with Callisto further east. Europa was visible closely west of Jupiter, with its shadow seen above the North Equatorial Belt. Ganymede was further west of the planet.

20:50 (21:50) I took a quick glance at the Moon, and the general view was very similar to that on April 14, but with the crater Hercules in deep shadow, and Atlas in part-sunlight.

21:00 (22:00) I viewed Io transiting the eastern Jovian limb, and also viewed the Great Red Spot prominently east of the planetary meridian.

21:15 (22:15) Europa’s shadow was by now near the western edge of the planet, with the satellite itself now further west.

21:50 (22:50) Europa’s shadow had now been gone for about half an hour, but that of Io was now taking its place, beginning its own traversal of the Jovian disk.

22:20 (23:20) Io’s shadow now well seen across the Jovian disk, with the Great Red Spot now well west of the planet’s meridian. The seeing and transparency were beginning to deteriorate.

22:50 (23:50) A thickening band of cloud obscured the planet and ended the session, which was a pity, since I would have seen Io emerging west of the planet with its shadow still on view. I promptly ended the session and parked the scope

May 14-15, 2005

Conditions: clear, calm, seeing 8-9, ZLM 4.8

Time (UT): 21:15 – 01.00

21:15 UT (22:15 local) Aligned the ETX on Regulus and Spica. This was probably going to be tha last night for quality deep-sky viewing for quite some time, with the waxing Moon and the increasing twilight forming an unholy alliance. In the end, it was a highly enjoyable night, with plenty of interest within our Solar System and well beyond.

I began with a study of the 6.5 day old Moon in the darkening sky. The main terminator highlights were the fine crater pair of Aristoteles and Eudoxus, with the dilapidated crater of Alexander to the latter’s south. Also in shadow, to the south of Mare Serenitatis, were the prominent crater of Menelaus and the Haemus Mountains, the ruined crater of Julius Caesar, and the rugged region of the Ariadeus Rille. To the south of Julius Caesar, Sabine and Ritter were prominent, as was Delambre. The crater-pitted region in the far south was dominated by a superb view of Maurolycus.

Prominent features away from the terminator included Posidonius, Plinius, the Theophilus chain, the pair of Zagut and Rabbi Levi, Piccolomini and the Altai Scarp.

22:00 (23:00) The celestial King of Beasts was beginning to drift westward, so I took a look at R Leo, the ‘Golden Castor’ of Gamma and the tough Iota. R Leo was now equal in brightness to the 6.5 mag star to its north, and Iota was cleanly split at 345x, with the companion at ‘three o’clock’ of the primary, signalling very good seeing.

Little was I to realise that Iota was a picnic compared to another double I saw later tonight !

HYPERACTIVE JUPITER

22:10 (23:10) This was meant to be only a routine look at Jupiter, but it ended up as anything but. The first look at the satellites revealed two west of the planet and three to the east. I thought, hang about, since when have there been five Galilean satellites ? I checked Sky and Telescope’s applet, and sure enough, it showed only Io to the west, with Europa, Ganymede and Callisto to the east. There was a seventh-magnitude stellar interloper in the telescopic field to confuse me ! After this shock, I then took a closer inspection of the planet’s disk and noticed something rather odd about the North Equatorial Belt. There was a strange ‘dark spot’ hanging off the Belt, almost on the Jovian disk’s meridian, just as the Great Red Spot proper was appearing on the eastern side of the planet. I hastily checked Sky and Telescope and confirmed what I thought – there were no shadow transits due tonight, so what was going on ? In any case, this feature was far larger than the shadow of Ganymede, but I was to find out that it was a large blue festoon, indicating vigorous activity in the Jovian atmosphere. After all this hoo-ha on Jupiter, it was time for a cup of strong tea !

22:45 (23:45) Jupiter’s Great Red Spot had now reached the planet’s meridian, whilst the Dark Spot had now moved well off to the west, about 90° ahead of the GRS.

22:55 (23:55) I then turned my attention to a few more first-time doubles in Boötes and Libra, now approaching the meridian.

In Libra, STF 1899 was a dimmer Albireo clone well seen at low power, and 18 Lib was a pale / dark orange pair with a rather faint companion. Further south, Lalande 123 (aka SAO 183565) was a nice white pair not unlike Gamma Arietis, well seen despite its low altitude.

I slewed north to Boötes, and 1 Boötis was a white / blue pair best seen at high power due to the faintness of the companion. The wide reddish / yellow pair of S656 was best seen at low power, even visible in the finder. STF 1871 was difficult to view as it was on the zenith, but high power showed it to resemble a dimmer Zeta Aquarii, with equal off-white components. Another off-white pair near the zenith, but much wider, was ADS 9474. I ended my survey of ‘second string’ doubles in Boötes with the wide white pair of STF 1921.

23:20 (00:20) It was time to take a casual look at the brighter globulars of M3, M5 and M13 before taking a short break.

ANTARES GIVES UP ITS SECRET - JUST

23:50 (00:50) I then took seized the opportunity to take on the toughest job of the night – splitting Antares in Scorpius. Clay Sherrod’s Constellation Guide said it could be done in an ETX-125, but there again, he wrote this from Arkansas, not Northern England !

The Rival of Mars was dimmed by haze, and at 10° - about as high up as it was going to get. I had succeeded with Iota Leonis earlier on tonight, so why not give it a try ?

I thus whacked in the 11mm eyepiece and barlow for 345x and expected the worst. The image of the star was distorted due to refraction, but, thanks to the good seeing, the Airy disk was rather better-behaved than I had feared, and definitely better than in the small hours of May 8. For several minutes I could see nothing but a red dot with a green upper edge and a boiling diffraction ring, when after ten minutes, the ring quietened down, and I glimpsed a tiny speck at 9 o’clock of the primary. This speck remained visible for only a second, as the diffraction ring reverted to its turbulent self, and I had to wait another quarter of an hour until I caught another fleeting one-second glimpse of the companion. Half an hour’s viewing, for two seconds’ worth of glory !

Antares can be 'done' in an ETX-125 from England, but with extreme patience.

00:20 (01:20) Still in Scorpius, I took a feelgood look at the ‘double double’ of Xi Scorpii and STF 1999, but then I examined three other doubles in the far-southern reaches of Ophiuchus.

While I was waiting for those southerly doubles to come into view, I took a casual look towards the northern horizon. Capella was at its lowest, but what struck me was the dark blue glow in the sky, reminding me that the season of all-night twilight was upon me !

00:30 (01:30) Xi Ophiuchi was the first to appear, and I could just see the 9th-mag companion at high power, although it was not quite as difficult as Antares. 39 Oph was more southerly, so it took a few more minutes to appear, but it was wider and less mismatched in magnitude, as well as being more colourful, with orange and reddish components. I had to wait another twenty minutes or so for 36 Oph, and so I killed the time with looks at M80, M4 and M19.

00.55 36 Oph finally came into view, showing its orange components well at high power, despite the low altitude of about 10°. Reducing to low power, I noticed two other orange stars in the same field.

01:00 (02:00) I heard the nearby church clock striking two. Not surprisingly, after the struggle with Antares, I was tiring, so I packed up the scope.

May 16, 2005

Conditions: hazy with variable cloud, seeing 6-7, ZLM did not check

Time (UT): 20.40 – 21.30

This was just a casual session, looking at the 8.5 day old Moon. The most striking feature was Plato, slap-bang on the terminator, but the seeing did not let me see any craterlets inside it at high power. Other notable features were the very wide shadow cast by the Straight Wall, and the eastern walls of Eratosthenes and Clavius just catching the first sunlight. Slightly away from the terminator, the Apennine Mountains and Ptolemaeus chain were unmistakable, as was the Purbach chain to the south. There was a group of craterlets near Walter giving the impression of a chisel-cut, like the Alpine Valley.

May 17, 2005

Conditions: hazy with high cloud, seeing 6-7, ZLM 4.0

Time (UT): 20:55 – 23:05.

This was a solar system viewing session, as the sky was too bright and hazy for much else.

Highlights were a last look at Saturn before it disappeared into the twilight, the 9.5 day old Moon, with Copernicus slap-bang on the terminator, and a transit of Ganymede.

20.55 UT (21:55 local) I enjoyed a casual wander round the features of the Moon. Copernicus was the main feature, a superb sight with its floor fully in shadow. The Clavius region was still striking, with Moretus to its south showing its prominent central peak well. The Straight Wall’s shadow was becoming thinner; Eratosthenes and the Apennines also notable.

21:10 (22:10) It was time to observe the final minutes of Ganymede’s transit. Jupiter’s Great Red Spot was visible near the planet’s meridian. Over the next quarter-hour or so, the satellite became visible as a bump off the west of Jupiter, until it was cleanly separated.

21:35 (22:35) Slewed the ETX to Saturn for a quick look. The Cassini Division was now becoming difficult to see due to the planet’s low altitude. Patches of cloud were rolling in, so I took a tea break.

22:35 (23:35) Returning to Jupiter, the GRS had moved well west in the last hour, and Ganymede well clear of the planet. Five minutes later, I could see the shadow of Ganymede nicking into the Jovian disk from the east.

22.55 (23:55) Cloud was thickening slightly, but there still was time for a look at the Moon. Copernicus appeared different from two hours earlier, as part of the floor was just beginning to receive sunlight.

23:05 (00:05) Back to Jupiter, and Ganymede’s shadow was now easily visible on the disk, well clear of the limb. The planet was fading in the eyepiece as thicker cloud dimmed everything over the next few minutes.

23:10 (00:10) Parked the ETX in the increasing cloud.

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