Between November 10 and 13 of this year we had another fine geomagnetic even caused by several CME that were hurled our way from a large sunspot group that was busy generating X class solar flares and associated CME outbursts. Aurora was seen across all of New Hampshire, through the entire continental USA and into Mexico. Emails came to us from friends in Arizona, showing aurora with saguaro cacti in the foreground: quite a sight! It was, fortunately, clear here that night after about 9pm until 2am, so we saw some fabulous aurora here. The magnetometer was also running and captured the event. Below you will find the images from both cell-phone and Nikon Z8 as well as the magnetometer traces. Note the times on these are in UTC for the days November 10, 11, 12, 13, 14. The Y-axis are in units of nT. Each day at 00h UTC, the variance is reset to 0nT by design.
Eclipses are always exciting, a pleasure to experience. This one was an early morning event with questionable weather…. and it was a complete joy to see! We had clear skies in the end, and a small geroup in attendance in the wee hours of the morning of March 14th. We kept the 16″ Schmidt-Cassegrain telescope open for visitors to enjoy, using our lowest magnification (50mm Plössl). The Moon gave us splendid views. Some images captured of the event are below:
This past month has certainly been spectacular for astronomical events. Aurorae have graced our skies with tremendous activity, Saturn is back to the early evening, as is Venus, and now a comet. The comet, C/2023 A3 (Tsuchinshan-ATLAS) was noted as being the comet of the century, but reservations must always been taken when making such predictions. This was a good comet, but not nearly as spectacular as NEOWISE (C/2020 F3), Comet McNaught, Hale-Bopp, or Comet Hyakutake (C/1996 B2)… all of which were tremendous and easily seen without optical aid. C/2023 A3 was nice but bright only for a brief few days while it was in the glare of the Sun near sunrise then just after sunset. As of this writing, it is rapidly fading though still viaible with small telescopes.
Our first view of the comet here in southern New Hampshire, was on the early evening of 12 October 2024 as it made its way around the Sun and approached Earth. We were able to see it just after sunset from the tallest building on campus, the Library. Looking west, it was only visible for about 30 minutes, but easily photographed with a telephoto.
By 17th October the comet was up for a longer period but was already fading. We captured a lot of imagery this evening with a group of students and faculty by the Hill Bridge looking back to the southwest over the Field House.
Note that the anti-tail is faintly visible in the above image.
By 18th October the comet was considerably higher in altitude and even fainter. I was unable to see it without a pair of binoculars. The comet was still not visible to the observatory domes. Image below.
On 24th October, the comet had risen enough to be visible in the 0.7m telescope, so we gave it a go and imaged in Lum and RGB for the following close-up images. These are about 25×25 arc-minutes in dimension. Each is a 20 minute total integration comprised of ten, 2-minute integrations. One is summed and shows the stars as a series of points giving a good indication of the comet’s rapid movement relative to the background stars. The other image is a median which removes the stars and allows one to enjoy the comet’s details without distraction.
Here are just a select few of the many hundreds of images we took on the night of Oct 10/11, 2024 from the campus fields. The observatory is in the distance to the north. Most of the night, aurora surrounded those of us in the fields: to the north, south, east and west. At times it was so bright that the cameras had to be adjusted so as not to overexpose. Two systems used: Nikon Z9 with 20mm, and Nikon D810A with 16mm fisheye. I got tired just after midnight, and the sky was still aglow. Reports have been coming in that it was still an active storm here until sunrise on the 11th. Quite an event!!
This has been quite the spring for astronomical activity! We’ve enjoyed a total solar eclipse, and now one of the largest auroral storms in some 20 years (the last big one was the Halloween storm of October 2003). Leading up to this event was the appearance of the huge sunspot groups 3668 and 3664.
As this group started to send out massive coronal mass ejections, it became apparent that these were headed right towards Earth: a good sign for geomagnetic phenomena, storming and auroral activity. The Space Weather Prediction Center started posting advanced watches then warning as the 11th of May approached. Sure enough, several of these CMEs combined into one large mass of solar material and slammed into our planet’s magnetosphere: aurora!
Starting out as faint greyish clouds, we knew these were not regular clouds as they danced and shifted shapes every few seconds. One moment, they would be small patches of light, the next, they would shoot up to the zenith and glow brightly before vanishing completely. As the storm progressed, color became apparent to the eye: pinks, greens, and violets started to show among a wall of color and light that filled most of the northern half of the sky.
We had set up two cameras to watch the storm progress: 20mm f/1.4 1000iso 1.3 second exposures all night long. Occasionally we’d shift their pointing direction to discover that fainter aurora was visible all the way to the southern horizon! Activity was rapid, changing constantly and colorful.
At the peak of the storm, there was considerable merging of aurora at the zenith. Below id a time lapse of this. The camera took a 1.3 second exposure with a separation of 1 second between each image. Here in the time lapse, each photo frame is 1/10 second in duration. The bright light passing through the video is a med-evac helicopter that passed overhead from Exeter Hospital.
All images taken from Pittsburg, NH, USA along the shore of Lake Francis. The closeup images were made using Nikon D850 and 500mm focal length lens. The wide field frame is from a Nikon D6 and 20mm wide field lens. All photos by J.A.Blackwell.
There are a lot of sites out there to help you get going with eclipse planning this time around. This will give you a lot of links and go-to sites for that information. Happy eclipse viewing!
Courtesy NASA
Rule one about solar eclipses is SAFE OBSERVING. Some of the sites on this list will have their own statements. Mine is here. It is important to know that solar observing at ANY time can cause irreversible damage to you and your equipment. Read statement here.
Planning: at this time, getting to and from remote locations is going to be challenging at best. Most flights around the eclipse date are filled. Hotels are also booked. If you are within driving range, be very aware that your drive times will be greatly increased traffic congestion. Our experience has been that getting to a site one or two days early is the easy part if you drive in. Driving out is next to impossible: again, wait a day or two to leave. People will try to part anywhere they can, from shopping center lots to the side of the highway. Be safe. Be kind to people. Crowds are challenging.
Not eclipses are total. Many are partial, and some are annular. An annular eclipse takes place when the angular size of the Moon in the sky is smaller than the angular size of the Sun in the sky. What makes this happen? Distances! The further away something is from your vantage point, the smaller is appears. During the eclipse of 14 October 2023, the Moon is close to its apogee, its furthest distance away from Earth in its orbit (remember that the Moon’s orbit is significantly elliptical). During an annular eclipse, if you are on the eclipse path, you will see the smaller Moon cover the Sun, but not completely. A small thin ring of the Sun will still be visible around the edge of the Moon. Be very careful! Annular eclipses are NOT safe to look at without proper solar filters or instrumentation!
The path of maximum eclipse passes from Texas through to the Pacific Northwest on this occasion. Others across the Americas will see a partial eclipse, an equally exciting opportunity. The chart below (NASA) shows the path.
14 October 2023 Annular Eclipse Map
A reminder: Observe safely. Even when this eclipse is in full annular mode, it is not safe to look at. It is also not safe to aim your camera at for any length of time, as your lens system could suffer damage, as could the sensor and shutter mechanism. Use proper filters!
As school gets out in early June, the time to start the maintenance routing begins. This all needs to get done before the Exeter Summer Session, a six week program that runs all of July and into the first two weeks of August. Checklist of To-Do items:
Wet clean all surfaces of the dome interior including the dome-to-structure interface (pollen and construction debris, spider webs, etc); walls; mount; telescope tube exterior; cables.
Remove any wasp nests and mud-doubed nest material.
Sweep out the debris on the floor, wet mop as needed.
Dry!
Micro-dust vacuum the optical tube interiors (open tube systems only).
Clean the optical surfaces.
Clean the eyepieces. These get really used hard and do not act favorably to eye makeup or DEET. Some get tossed, sadly, each year.
Replace lubricant on two of the mounts which get annual lube changes. We use Lubriplate 105 for the worm and drive gears on the Paramounts, per Software Bisque’s maintenance plans.
Replace any optical components that have given-in to New Hampshire weather conditions. Usually the V Photometric filters are first to go, as their glass recipe is reactive to high humidity and sea salt nuclei in the air. Being near sea level does not help.
Take new darks, biases and flat field frames.
Clean out any debris in the weather station.
This last year we replaced the rubber matting that seals the dome-to-structure interface, covering the rollers and the opening to the outside world. The original covering was thirty years old! The new material is a smooth surface and not porous like the previous covering. This makes for easier wet cleaning and faster drying.
The results? Clean operational status!
The Takahashi refractor for visual and wide-field photographic use.The 0.7m telescope with CCD and Spectrograph.Kurtz Dome 16″ Meade Flat Field SCT primarily for visual use.
Advanced astronomy classes this spring had the opportunity to hone their skills at image data extraction and analysis with a telescope we have been operating in the southern hemisphere. This spring, a classical nova erupted, reaching V magnitude ~ 6.7 or so before fading. We collected data every clear night in photometric filters, V, B and R for analysis and submission to the AAVSO. When done, students had correctly analyzed 176 data points and submitted those as observer GPE (Grainger Phillips Exeter), our AAVSO initials. Below is a plot of the V, B and R data from the AAVSO which includes our data and those from all the other observers who took part in observing this star.
Apparent magnitudes in V, B and R are on the ordinate. Julian Date is on the abscissa. The colors denote filters used: Red = R, Green = V, and Blue = B photometric filters. We acknowledge with thanks the variable star observations from the AAVSO International Database contributed by observers worldwide and used in this research.
ExeterAstro 