Tag Archives: Neptune

IOTA Announcement – Occultation By Neptune’s Moon Triton – 5 October 2017

Greetings, fellow astrophiles!

The following recently came across the ASRAS email list from ASRAS and IOTA member Brad Timerson. If you’ve the gear for it, this is an excellent chance to contribute to some far-out science.

There will be an occultation of a 12.5-mag. star by Neptune’s large satellite Triton the early evening of October 5th (just before 8pm EDT) that will be visible from east of the Appalachian Mountains. It’s the brightest star to be occulted by Triton since the Voyager flyby showed that the satellite has a substantial atmosphere with interesting dark plumes. The occultation will allow us to learn more about the atmosphere, and its variation with altitude and latitude. Sofia plans to fly over the Atlantic, to try to catch the central flash, where Triton’s whole atmosphere will focus/amplify the star’s light, probing deeper parts of the atmosphere. This might also be observed from Florida, but observations anywhere from the East Coast area are sought, to sample a wide range of latitudes of Triton’s atmosphere. Details of the occultation are available at MIT’s Web site for the event at hubble.mit.edu/prediction.html.

The central time for the Rochester area is within several seconds of 7:55:40 pm EDT on October 5th. For an observer near the center of the path, the event could last as long as 3 minutes. Because the Rochester area is north of that path, any occultation or atmospheric dimming would likely last some fraction of that time. You should plan to record the event for about 10 minutes before and after the time shown here.

A main challenge of the event will be to record Triton and the target star with a good signal, preferably with clear separation between 8th-mag. Neptune less than a quarter arc minute away. You will need good scale to separate the objects well enough. More observing tips are given on the MIT web site. The target star is about a magnitude brighter than Triton.

Telescopes as small as 8″ Newtonians will show the target star. (see included image from a European observer) For occultation work, we don’t need to “see” the occulting body (Triton in this case), just the object being occulted. Low light and/or integrating video cameras are best for this observation. However, standard astronomical cameras operated in a mode so as to produce images as quickly as possible will also work. Testing ahead of time to determine the correct exposure to just barely detect Triton should be done. This is to insure that the light from nearby Neptune doesn’t overwhelm that of the nearby moon and star at the time of the event.

Target star, Neptune, and Triton.

I plan on using my 10″ Meade LX200GPS at either f/6.3 (focal reducer) or at the normal f/10 prime focus. I will be using a Watec 120N+ low light video camera and integrating for 64 or 128 frames (2 seconds and 4 seconds). I’m still experimenting and might even need longer integration times.

Triton occults 4UC 410-143659, 5 October 2017 – visible regions from Earth.

Everyone with suitable equipment is encouraged to try this event. And I would appreciate it if this message is forwarded to any nearby universities that might have the ability to observe this event. If individual images are taken (instead of video) the exact time for each exposure is required (don’t depend on the computer’s internal clock. Use a GPS-based time). For analysis, it may be possible to measure the light level on individual images or the images can be combined into a video and measuring software used on the video.

Please contact me (EMAIL) for additional information or to submit observations.

NASA Space Place – Is There A Super-Earth In The Solar System Out Beyond Neptune?

Poster’s Note: One of the many under-appreciated aspects of NASA is the extent to which it publishes quality science content for children and Ph.D.’s alike. NASA Space Place has been providing general audience articles for quite some time that are freely available for download and republishing. Your tax dollars help promote science! The following article was provided for reprinting in August, 2016.

By Dr. Ethan Siegel

2013february2_spaceplaceWhen the advent of large telescopes brought us the discoveries of Uranus and then Neptune, they also brought the great hope of a Solar System even richer in terms of large, massive worlds. While the asteroid belt and the Kuiper belt were each found to possess a large number of substantial icy-and-rocky worlds, none of them approached even Earth in size or mass, much less the true giant worlds. Meanwhile, all-sky infrared surveys, sensitive to red dwarfs, brown dwarfs and Jupiter-mass gas giants, were unable to detect anything new that was closer than Proxima Centauri. At the same time, Kepler taught us that super-Earths, planets between Earth and Neptune in size, were the galaxy’s most common, despite our Solar System having none.

The discovery of Sedna in 2003 turned out to be even more groundbreaking than astronomers realized. Although many Trans-Neptunian Objects (TNOs) were discovered beginning in the 1990s, Sedna had properties all the others didn’t. With an extremely eccentric orbit and an aphelion taking it farther from the Sun than any other world known at the time, it represented our first glimpse of the hypothetical Oort cloud: a spherical distribution of bodies ranging from hundreds to tens of thousands of A.U. from the Sun. Since the discovery of Sedna, five other long-period, very eccentric TNOs were found prior to 2016 as well. While you’d expect their orbital parameters to be randomly distributed if they occurred by chance, their orbital orientations with respect to the Sun are clustered extremely narrowly: with less than a 1-in-10,000 chance of such an effect appearing randomly.

Whenever we see a new phenomenon with a surprisingly non-random appearance, our scientific intuition calls out for a physical explanation. Astronomers Konstantin Batygin and Mike Brown provided a compelling possibility earlier this year: perhaps a massive perturbing body very distant from the Sun provided the gravitational “kick” to hurl these objects towards the Sun. A single addition to the Solar System would explain the orbits of all of these long-period TNOs, a planet about 10 times the mass of Earth approximately 200 A.U. from the Sun, referred to as Planet Nine. More Sedna-like TNOs with similarly aligned orbits are predicted, and since January of 2016, another was found, with its orbit aligning perfectly with these predictions.

Ten meter class telescopes like Keck and Subaru, plus NASA’s NEOWISE mission, are currently searching for this hypothetical, massive world. If it exists, it invites the question of its origin: did it form along with our Solar System, or was it captured from another star’s vicinity much more recently? Regardless, if Batygin and Brown are right and this object is real, our Solar System may contain a super-Earth after all.

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

August2016.en

Caption: A possible super-Earth/mini-Neptune world hundreds of times more distant than Earth is from the Sun. Image credit: R. Hurt / Caltech (IPAC)

About NASA Space Place

With articles, activities, crafts, games, and lesson plans, NASA Space Place encourages everyone to get excited about science and technology. Visit spaceplace.nasa.gov (facebook|twitter) to explore space and Earth science!

Observing Update: North Sportsman’s Club Session Is ON For Tonight, Saturday Oct. 10th

Greetings fellow astrophiles!

A red-lit view of the NSC building (and several tens of billions of stars towards the galactic center).

It’s looking good enough tonight for the session (very partial cloud cover, which is good enough given past scheduled events), so we’ll be at NSC from 8 to 11. We’ll lose Saturn soon after 8:00 p.m. to our Southwest, leaving Neptune and Uranus as the planetary viewing for the night (and we can, at least, look in the direction of Pluto). The night will be peppered with great objects, from our own backyard to sights beyond our Local Group.

The NSC in google maps. Click to generate directions.

For additional details, check out our original post: Two (Maybe Three) Saturday Sessions Announced For The North Sportsman’s Club – Sept 12th, Oct 3rd, And (Maybe) Oct 10th