Mercury at Superior Conjunction

Today Mercury is passing through superior conjunction, passing around the far side of the Sun as seen from our earthbound vantage point. This fast moving planet will reappear in the sunset in about a week, rising towards maximum elongation on June 23rd.

The June apparition will be the best of the year with the planet reaching over 25° from the Sun. The October apparition will be quite good as well at over 24°.

Mercury Events for 2019
ApparitionDate ElongationMagnitude
Evening Feb 2718.1°E -0.2
Morning Apr 1127.7°W +0.6
Evening Jun 2325.2°E +0.7
Morning Aug 919.0°W +0.3
Evening Oct 2024.6°E +0.1
Morning Nov 2820.1°W -0.3
Data from the Mercury Chaser’s Calculator by John Walker

Waimea Lāhainā Noon Reminder

Today at 12:19HST will be Lāhainā Noon in Waimea on the Big Island, the moment when shadows disappear.

The exact date and time varies significantly across the islands and from year to year. The table below shows the time of Lāhainā Noon for various cities in 2019.

Lahiana Noon for May 2019
CityLong.Lat.DateTimeElevation
Naalehu 155°35’W19°03’NMay1512:19HST89.9
Hilo 155°05’W19°42’NMay1812:17HST89.9
Kona 155°59’W19°39’NMay1812:20HST89.9
Waimea 155°40’W20°01’NMay2012:19HST89.9
Hawi 155°50’W20°14’NMay2112:20HST90.0
Hana 156°00’W20°46’NMay2312:21HST89.9
Kihei 156°27’W20°45’NMay2312:23HST89.9
Kahalui 156°28’W20°53’NMay2412:23HST89.9
Lahaina 156°40’W20°53’NMay2412:23HST89.9
Lanai City156°55’W20°50’NMay2412:24HST89.9
Kaunakakai157°01’W21°05’NMay2512:25HST89.9
Honolulu 157°49’W21°18’NMay2612:28HST89.9
Kaneohe 157°48’W21°25’NMay2712:28HST89.9
Waialua 158°08’W21°34’NMay2812:30HST89.9
Lihue 159°22’W21°58’NMay3112:35HST90.0
Data from US Naval Observatory Data Services

June Observing List

Our next club dark sky star party will be June 1st at the usual Kaʻohe site.

Omega Centauri
Omega Centauri, NGC5139

For the evening I have again assembled an observing list for those who want to explore some of the more interesting objects available in the sky this month.

These are all visible in the early evening, all suitable for average telescopes of at least 6-8″ aperture.

M5
RA: 15h 18′ Dec: 2° 4’N Mag: 5.8 Globular cluster in Ser
A nice bright globular, about 15′ in diameter

Iota Cnc
RA: 8h 46′ Dec: 28° 46’N Binary star in Cnc
A pretty yellow and white pair, 4.0 and 6.6 separated by 30″

V Hya
RA: 10h 52′ Dec: 21° 15’S Mag: 8 Carbon star
Reddest carbon star known variable from 6.5-12 magnitude with a period of 533 days

M92
RA: 17h 17′ Dec: 43° 8’N Mag: 6.5 Globular cluster in Her
This nice globular cluster is often overlooked in favor of its more famous neighbor M13, but M92 is also worth the stop.

NGC6207
RA: 16h 43′ Dec:36° 50’N Mag: 11.6 Galaxy in Her
Just 28′ north of M13 this faint 11th magnitude galaxy is a nice challenge object for eight inch or larger optics.

NGC5846
RA: 15h 6′ 29.3″ Dec: 1° 36′ 20″N Mag: 10.2 Galaxy in Vir
A bright elliptical, those with larger aperture may note a small companion galaxy on the south edge of the halo

M99 Coma Pinwheel Galaxy
RA: 12h 18′ 49.7″ Dec: 14° 24′ 59″N Mag: 9.8 Galaxy in Com
A nice spiral galaxy, larger aperture will show some of the spiral structure

NGC5128 Centaurus A
RA: 13h 25′ Dec: 43° 1’S Mag: 7 Galaxy in Cen
A large bright galaxy with an obvious dust lane

Proxima Cen
RA: 14h 29′ 43″ Dec:62° 40′ 46″S Red dwarf star
The closest star outside our solar system, a challenge object to be sure, you will want good charts to find this one. The coordinates given above are from the Gaia mission data release 2 and are recent enough to be accurate, this high proper motion star moves about 4 arcseconds each year.

NGC5286
RA: 13h 46′ Dec: 51° 22’S Mag:7.6 Globular in Cen
Another nice, but oft overlooked globular star cluster

Keep in mind that this list is assembled for the usual West Hawaii Astronomy Club observing site at Kaʻohe, on the side of Mauna Kea at 20N latitude. It may include southern objects out of reach for anyone much further north.

Hilo & Kona Lāhainā Noon Reminder

Today will be Lāhainā Noon in Hilo and Kailua-Kona, the moment when shadows disappear.

The event will occur at 12:17HST in Hilo, and three minutes later further west in Kailua-Kona at 12:20HST.

The exact date and time varies significantly across the islands and from year to year. The table below shows the time of Lāhainā Noon for various cities in 2019.

Lahiana Noon for May 2019
CityLong.Lat.DateTimeElevation
Naalehu 155°35’W19°03’NMay1512:19HST89.9
Hilo 155°05’W19°42’NMay1812:17HST89.9
Kona 155°59’W19°39’NMay1812:20HST89.9
Waimea 155°40’W20°01’NMay2012:19HST89.9
Hawi 155°50’W20°14’NMay2112:20HST90.0
Hana 156°00’W20°46’NMay2312:21HST89.9
Kihei 156°27’W20°45’NMay2312:23HST89.9
Kahalui 156°28’W20°53’NMay2412:23HST89.9
Lahaina 156°40’W20°53’NMay2412:23HST89.9
Lanai City156°55’W20°50’NMay2412:24HST89.9
Kaunakakai157°01’W21°05’NMay2512:25HST89.9
Honolulu 157°49’W21°18’NMay2612:28HST89.9
Kaneohe 157°48’W21°25’NMay2712:28HST89.9
Waialua 158°08’W21°34’NMay2812:30HST89.9
Lihue 159°22’W21°58’NMay3112:35HST90.0
Data from US Naval Observatory Data Services

May 18th, 1980

Living with an eruption of our local volcano through much of last year often brought to mind previous memories. The 2019 Kilauea eruption was the second eruption of my life, the first being the 1980 eruptions of Mt. St. Helens.

The eruption of Mt. St. Helens taken on the morning of May 18th, 1980, photo credit USGS
The eruption of Mt. St. Helens taken on the morning of May 18th, 1980, photo credit USGS

St. Helens was just another of the pretty mountains that dotted the horizon through much of my childhood. I could see it from my bedroom window, at least in the winter when the leaves were off the trees.

When the mountian started rumbling in the early months of 1980 everyone wondered if it will erupt. No one expected it to do what it did.

We did not hear the eruption, somehow the sound skipped over those nearer the volcano. It was the television news that first alerted us.

Seeing the reporting I ran out of the house and down the street a little bit to where I could see past the maple trees. There was nothing to be seen of that pretty mountain, just a dark line in the sky rising from where the mountain stood. West of the line it was a cloudy NW sky, east of the line is was just black.

After the eruption we could no longer see the mountain on the horizon, with 1,500ft gone from the top it no longer stood above the ridgelines.

Lāhainā Noon

Lāhainā Noon is that moment when the Sun is directly overhead. At the moment of Lāhainā Noon shadows disappear.

As the islands lie south of the Tropic of Cancer there is a day when the Sun will pass directly overhead as the summer solstice approaches, generally in late May. There is a second noon as the Sun’s position moves south again in July.

The term Lāhainā Noon is unique to the islands, being adopted by the Bishop Museum in the 1990’s to describe this event. The Hawaiian term lā hainā translates roughly as cruel Sun.

The exact date and time varies significantly across the islands and from year to year. The table below shows the time of Lāhainā Noon for various cities in 2019.

Lahiana Noon for May 2019
CityLong.Lat.DateTimeElevation
Naalehu 155°35’W19°03’NMay1512:19HST89.9
Hilo 155°05’W19°42’NMay1812:17HST89.9
Kona 155°59’W19°39’NMay1812:20HST89.9
Waimea 155°40’W20°01’NMay2012:19HST89.9
Hawi 155°50’W20°14’NMay2112:20HST90.0
Hana 156°00’W20°46’NMay2312:21HST89.9
Kihei 156°27’W20°45’NMay2312:23HST89.9
Kahalui 156°28’W20°53’NMay2412:23HST89.9
Lahaina 156°40’W20°53’NMay2412:23HST89.9
Lanai City156°55’W20°50’NMay2412:24HST89.9
Kaunakakai157°01’W21°05’NMay2512:25HST89.9
Honolulu 157°49’W21°18’NMay2612:28HST89.9
Kaneohe 157°48’W21°25’NMay2712:28HST89.9
Waialua 158°08’W21°34’NMay2812:30HST89.9
Lihue 159°22’W21°58’NMay3112:35HST90.0
Data from US Naval Observatory Data Services

Building a Wall

The project that has consumed my weekends for several months is complete. The wall is finished. I poured the last bags of concrete this weekend, I stacked the last rocks into place.

Retaining Wall
Fitted local stone makes up a small retaining wall,

It is done!

Thus I have spent many a weekend digging, more digging, hauling soil and rock, then pouring concrete. I found that about ten bags of concrete was a good work session, about as much as I could do in one go. It is also as much as I wanted to load in the vehicle, 600 pounds a heavy while safe load for the Explorer.

Other work sessions were simply fitting rocks. Selecting likely rocks, spinning them about and finding reasonable fits, tossing aside those that did not fit. With a single layer added to ten or twenty feet of wall I could then spend the next work session pouring concrete and cementing that layer of fitted stone into place. Rinse and repeat.

Continue reading “Building a Wall”