Gazing up at the sky while reading the old texts one would not be amiss in believing that the stars never change. Indeed there are many who insist vehemently that the stars are eternal and unchanging. But the stars do indeed change, often quite visibly, sometimes within the span of a human lifetime.
A VLT/SPHERE image of L2 Puppis showing the enveloping cloud of gas and dust representing an early stage planetary nebula. Image credit ESO/P. Kervella used under Creative Commons 4.0
One such star is L2 Puppis.
A bright star, one of the few naked eye variable stars that could be seen to fade and reappear without the aid of a telescope much like the far more famous stars Mira and Algol. On star charts the star is found prominently drawn at magnitude 4, buf if you attempt to locate it today you will not find it without the use of a telescope.
I first encountered this star quite recently while starhopping through southern Puppis with an 8″ telescope from the driveway. The chart showed two bright stars close together, L1 Pup and L2 Pup, while the view in the finder ‘scope showed only one bright star.
Wandering the sky using a telescope and a field guide published in 1844, the better part of two centuries ago, is… uhhm… interesting. In mid-April the classic winter constellations are dissapearing into the sunset, with constellations like Monocerus and Puppis well placed for observing from my driveway just after dark. On my observing table is a reprint of that 1844 field guide, The Bedford Cycle.
At the telescope in the driveway again
Working through the entries I come to the entry for a double star Argo Navis 72 P. VIII, a designation from a very old catalog. It takes a few moments research to convert 72 P. VIII to the slightly more modern catalog number HD 71176. Modern? The Henry Draper Catalog was first published by Harvard Observatory in 1918, still over a century ago.
With the HD number I can look up the position on a modern chart and spend a few moments star-hopping the Astrola to the correct star. This double star is now located in the constellation Puppis after the ancient and absurdly large constellation Argo Navis was broken up into Puppis, Vela, and Carina.
At this point I know not to trust my sense of time or internal clock, I have traveled across far too many time zones. Entebbe to Portland required 27 hours of travel and crossed ten time zones. My body is simply not to be trusted.
The previous evening had consisted of little more than making it from the airport to my parent’s house, then directly to a long sought bed.
The clock reads nearly 7am.
How can this be? The time seems wrong and I have no confidence in the old LED alarm clock in the guest bedroom. Was it set properly? I fumble for the cell phone to double check the time. The phone confirms the seemingly inaccurate time.
So I pressed the conversation longer than I really should have. But I did discover a number of motivations behind the obstinate adherence to an easily disproved view of the world. It took more conversation, but his motivations did become clearer.
The 2017 total solar eclipse as photographed from central Oregon
To no surprise part of the reason is religion. When he began to quote bible verses in support of his claims of a “immovable” Earth one can begin to see where he is starting from.
Our flat, enclosed, immovable earth is absolute proof of a creator. God is real. We don’t have to believe in Him anymore. We can know it to be true. Flat earth absolutely destroys the atheist/humanist worldview. Just like that.
If one begins with the belief that the Earth is flat, it is easy to reinforce that idea in this modern internet age. A thriving community of flerfs form one of the clearest examples of an echo chamber to be found on the net, a cult really. Circulating photos and YouTube videos reinforce the worldview, ridicule the “globe heads”, cement a community together in a belief of “true knowledge”.
When shopping for a focuser you face a lot of choices. From the cheap eBay Chinese options to the top-of-the-line Moonlights and Feather Touch. I once again perused these options when buying a new focuser for the Cave Astrola.
The ScopeStuff 2″ Crayford Focuser mounted to the 8″ Cave AstrolaIt has been a while since I looked at what was out there. So I spent some time shopping and wandering website re-educating myself on what the options were.
I considered the cheapest end of the market, a few options found on eBay, and again at the top-of-the-line, machined works of art that cost as much as some telescopes. This time I was limiting the budget for restoring the Astrola, not wanting to spend much more than a hundred on the focuser to keep the cost of the whole effort down.
Time to remind everyone of the common rules for star party etiquette. As few simple considerations for your fellow star party participants help make the event more enjoyable for everyone.
The 20″ Obsession telescope awaiting full dark at Kaʻohe, on the side of Mauna Kea
Not to say these are hard rules, they will get broken. Try not do break these rules… It is simply a matter of courtesy to other star party participants. Be polite and you will be far more welcomed to share the experience under a dark sky.
The points of etiquette below apply to any star party you might attend, with a few added bits particular to our West Hawaii Astronomy Club events.
Even when Venus is high in the sky and well placed for observation I will seldom take the effort of turning a telescope towards the planet. Why? Because Venus is pretty boring to look at. Perpetually cloud covered it has all the detail of a cue ball. It is a white disk with nothing of note to be seen. Yeah, pretty boring. Now turn the telescope to Jupiter.
Venus approaching inferior conjunction, 24Dec2013One exception to this occurs when Venus is approaching, or just emerging from inferior conjunction. As the planet passes between the Earth and the Sun we are looking at the nighttime side of the planet, with only a little of the daytime side to be seen. As a result Venus will appear as a brilliant crescent.
This begins as the planet passes maximum eastern elongation, about two months before inferior conjunction. At this point the planet is seen from the side with respect to the sunlight, the planet will be about half illuminated. In the weeks after maximum elongation the planet will appear ever more crescent.
Venus on 28May2012, about 12°44′ from the SunThe last weeks before conjunction, as Venus is very low in the sunset, or the first weeks after conjunction as it sits very low in the dawn are the most interesting. During this time the planet is a very fine crescent, quite a beautiful sight in the telescope. Many observers, including myself, have made a point to observe Venus at this time, the one time this planet really becomes interesting to view.
Imaging Venus in the daytime a mere 12°44′ from the Sun.As the planet is quite low in the sky it makes it a challenging telescopic target and distortion by the atmosphere can be troubling, blurring the view.
It is possible to enjoy this sight in the daytime, while the planet is high in the sky, the seeing can be better and the view sharper. Of course this also occurs when the planet is near the Sun, thus extreme caution should be practiced at the telescope to avoid any direct sunlight and possible eye damage.
A page from Galileo’s 1623 treatise The Assayer—Il SaggiatoreThe phases of Venus are quite interesting from a historical standpoint. The phases of Venus clearly show that the planet revolves around the Sun. The phases were one of the primary arguments used by Galileo in his treatise The Assayer—Il Saggiatore published in 1623, where he lays out many of his ideas on science itself and how observation and experimentation should be primary.
While the the evidence challenged prevailing ideas of the time, some astronomers attempted to explain the phases of Venus by any other means to preserve their Earth centered universe, which led to rather tortured models of planetary motion. But it was clear to most that Galileo was right, the simple and elegant answer was that the Sun lay at the center. The orbits of Mercury and Venus, the phases, along with other observations like the moons of Jupiter, were hard evidence that few could ignore.
In 2017, eastern elongation occurred on January 12th. By now Venus has begun to show a substantial crescent, about 30% illuminated if you look today, Feb 12th. Over the next few weeks as the planet sinks into the sunset, the crescent aspect will thin dramatically.
By the end of February the planet will be only 17% illuminated, another week after that it becomes only 11%, by which time the planet will be difficult to spot in the sunset. Inferior conjunction will occur on March 25th. A couple weeks later and it will be possible to spot the planet in the dawn and observe the now thickening crescent.
With the Moon only a few degrees from Venus this afternoon, it should be relatively easy to spot the brilliant planet long before sunset.
Venus photographed on 28May2012, about 13° from the Sun in the mid-afternoon skySpotting planets in the daytime is not that difficult, both Jupiter and Venus are bright enough to seen in full daylight. Venus is currently near maximum brilliance at about -4.6 magnitude, easily bright enough to see in a clear sky. There are a few helpful hints to make this easier.
Today the Moon will aid finding Venus in the sky as it is about 5° north of the Moon. Having the Moon nearby will not only aid in locating the Planet, it will also provide your eyes something to focus on.
Of course these bright objects will be even more dramatic after sunset when Mars will also be visible nearby.
The data produced by the W. M. Keck Observatory is available for anyone to view. This may come as a surprise to some who assume that astronomers hoard their precious data and jealously deny any access. I have also seen claims by anti-TMT activists who claim that telescope data is secret and access is restricted to some authorized group. It is a common theme I have seen repeated quite a few times during the Astronomy on Mauna Kea debate.
An image of Saturn taken in infrared light by NIRC2, image credit KOA/dePater
“There is an appointment signup of experts of bureaucrat choosing and the findings disappear amongst the grant supported or institutions we have no knowledge about” – Claire Templeton in a Facebook comment 16Aug2015
The idea is at least understandable. Much of modern astronomy is fairly arcane to the layman, not easily understood and seemingly mysterious. It does not have to be that way, the images and data are fully public. A small community, including astronomers and amateur astronomers, has learned to use the data to do science, or to simply peruse for their own edification. All it takes is an evening of educating yourself and you have access to a huge array of data.
The astronomers do guard their data and deny others access, but they are only allowed to do this for a limited period of time. This gives the astronomer exclusive use of their data long enough to complete the research and publish the paper. The amount of time they have exclusive use varies by telescope and institution, but it is usually a year or two. For the W. M Keck Observatory the data is usually embargoed for 18 months. Once the exclusive period expires the data is available to anyone and is posted in the online public archive.
Keck’s archive is known as KOA, or Keck Online Archive. Also a nice reference to the beautiful Koa forests that are common on the windward slopes of Mauna Kea. Here you can search and peruse twenty years of Keck data.
