Wolf 359 Star Parallax

Using Insight Observatory's 16" f/3.75 Dream Aerospace Systems astrograph reflector (ATEO-1) remote telescope, a Romanian team of amateur astronomers participated in the international project #NHParallax. This project is aimed to highlight the parallax effect by comparing image frames from the New Horizons space probe combined with frames obtained by ground-based remote telescope ATEO-1 located in New Mexico, USA.

Introduction:
Historically, the first determination of the distance to the stars was made by astronomer Friedrich Bessel in 1838 for the star 61 Cygni using the parallax method. This method remained the standard procedure for calibrating other methods for determining distances in the Universe. The parallax of a star is the angle through which the radius of the Earth's orbits is seen from the star when it is perpendicular to the Earth-Star direction. The simplified model of the parallax effect is illustrated in Figure 1. It involves a change in the apparent position of a star relative to the stars from the background when observed from two different locations. This is quantified by the angle p - called the parallax.

Figure 1 - Parallax Effect

For the calculation of the distance, we refer to Figure 1.

The following equations can be written:

tg (p ”) = Earth-Sun Distance / Sun-Star Distance
tg (p ”) = 1UA / D, from which it follows that:
D = 1 / tg (p ”)
Since the angle p ”is very small (less than one second of arc) we can approximate tg (p”) = p ”and the formula becomes:
D = 1 / p ”,
where D is expressed in parsecs (pc)
p” is expressed in arcseconds and 1 AU represents an astronomical unit, ie the average Earth-Sun distance.

Traditionally the distances to Proxima Centauri and Wolf 359 were calculated using this method and resulted in the following data confirmed by the specialized space missions Hiparchos and Gaia:

p”Wolf 359 = 0.41516” ± 0.000162 ”

The distance to the star Wolf 359 = 2,409 ± 0.009 pc, ie 7.86 light-years (+/-0.03 ly) 

Remarks:
On April 22, 2020, we made observations with the ATEO-1 remote telescope in tandem with the New Horizons space probe at nearby star Wolf 359. The advantage of these tandem observations is that the New Horizons probe is 46 times the Earth-Sun distance, which causes the perspective of the probe on the star Wolf 359 to change visibly from the perspective observed on earth. With such a large distance between the two observation points (Earth - New Horizons), the parallax effect is easy to highlight by comparing photos taken from Earth with those received from the New Horizons probe. Here is the animation which shows a stereo view of this phenomenon.

Wolf 359 Star animation with image data acquired from the New Horizons space probe
 and Insight Observatory's ATEO-1 remote telescope located in New Mexico.

The raw images obtained by the New Horizons space probe were downloaded from the website below dedicated to this project:

http://pluto.jhuapl.edu/Learn/Parallax/Parallax-Images.php

The camera used by the space mission was the Long-Range Reconnaissance Imager (LORRI). The raw images required some processing to eliminate image artifacts. This was done in the following steps:

- Creation of synthetic flat and removal of cosmic rays and hot pixels.
- Slight convolution of stars.

In order to measure the parallax angle, we must calibrate the two images in coordinates relative to the celestial sphere. This calculation was performed using the Astrometry.net program.

We determined the astrometric solution of the plate in the ICRS J2000 (International Celestial Reference System). Because the LORRI camera aboard the New Horizons spacecraft was designed to take images of trans-Neptunian objects, its resolution is only 4,09 arcsec/pixel as opposed to the much better resolution ATEO-1 telescope provides, ie 1,237 arcsec /pixel.

Results:
Since the geometry of the observations is more general than in the simplified model, respectively the Wolf 359 star is not centered in relation to the observation base. We first measured the angular distance between the star and the New Horizons probe at the date of the observation. The following were obtained:

θNH-Wolf359 = 125.20785° - The angular separation between New Horizons and Wolf 359.

According to the Jet Propulsion Laboratory website at the time of the observations, the distance between the Earth and the New Horizons spacecraft was 46.8534 AU, ie 7.028 billion kilometers. We measured the position of the Wolf star on the New Horizons frames and on the images obtained with the ATEO-1 telescope. We used all the images (3 provided by the New Horizons probe and 6 purchased with the telescopes we used) and averaged these measurements. To evaluate the measurement error we calculated their standard deviation. The results obtained are presented in Table 1.

Table 1: Wolf 359 star coordinates in both images obtained by the 
New Horizons probe and ATEO-1 telescope - ICRS2000.

An important aspect of these measurements, given that the pixel size is large compared to the star's profile, is the algorithm for identifying the centroid of each star in the images. For this, we used two methods: the position of the brightest pixel and the algorithm proposed by the AstroImageJ program.

To calculate the parallax, we used the formula for calculating the angular separation (Jean Meus - Astronomical Algorithms). In this formula, α and δ are the right ascension and the declination and the indices 1 and 2 correspond to the measurements with our telescope, respectively with the New Horizons probe.

cos d = sinδ1 sinδ2 + cosδ1 cosδ2 cos (α1 - α2)

Based on this formula we obtained the following parallaxes. I marked it with d to differentiate it from the meaning described in the introduction.

d”Wolf359 = 16,479” ± 3,390 ”

Figure 3: The geometry of the Earth, New Horizons space probe, and Wolf 359 star on April 22, 2020.

Taking into account the geometry of the observation (Figure 3) the distance can be calculated using the formula:

distEarth-Wolf359 ≈ distEarth-New Horizon / tg (d”) * sin (θ),

where distEarth-Wolf359 is the distance from Earth to the Wolf star, distEarth-New Horizon= 46.8534 AU is the distance from Earth to the New Horizons probe, and sin (θ) is the factor that takes into account the geometry of the observation.

We obtained the following distance for Wolf star:

distEarth-Wolf359 = 7,576 ± 1,559 light-years.

Conclusions:
This result corresponds to the recent determinations reported by the Gaia space mission and presented in the introduction. Our measurement has a lower degree of accuracy due to the low resolution of the LORRI (Long Range Reconnaissance Imager) camera with which the images from the New Horizons probe were recorded. This camera has a resolution of 4.09 ”/ pixel which means that a one-pixel position measurement error is a 10-20% parallax error (depending on the star). The approximations made in this calculation are insignificant in relation to the error in determining the position.

NASA's #NHParallax project to measure parallax by performing tandem observations on Wolf 359 and Proxima Centauri stars with the New Horizons spacecraft was purely educational, with NASA encouraging amateur astronomers around the world to make observations with their instruments at the same time as the space probe.

More details about this project can be found on the official website of the New Horizons mission:

http://pluto.jhuapl.edu/Learn/Get-Involved.php#NHparallax

The FITS files from the New Horizon space probe can be downloaded here:

http://pluto.jhuapl.edu/Learn/Parallax/Parallax-Images.php

The movement of the two stars is very difficult to visualize in the frames recorded on Earth, six months away because the parallax angle is extremely small compared to the star profile caused of the atmospheric disturbance recorded by the best observatories. The present project has managed to clearly illustrate this effect.

Authors Affiliation: 
Daniel Bertesteanu - Bucharest Astroclub
Marcel Popescu - Astronomical Institute of the Romanian Academy
Marian Naiman - Bucharest Astroclub

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Look - Up in the Sky: It's a Bird! It's a Plane!

... Well, yes, it probably is.

As an astronomer, with an interest in astrobiology and, therefore, in the possibility that life exists elsewhere in our universe - invariably, almost daily - someone will ask me something like: "Do you believe in aliens and UFOs?" My answer is, generally, something like: "I *ABSOLUTELY* believe that "they", are out there. They're just not, here."  But they don't like that answer, and at that point, the conversation usually turns to question the current state of my sanity: "How can you possibly believe in life in the universe - but NOT in UFOs?" Well, there are some really good reasons for this; and, here is my answer:

THE SHORT STORY:

1) Universal Constants There is no 'getting around' such things as universal constants: they are constants because they are, by nature, unchangeable; nothing can alter them. They obey inherent, long-proven, immutable laws of physics that are the same - everywhere in the universe. (How we know this, is another, very long story - so forget it.)  But, what this means, is that, no, intelligent, alien life-forms (or, 'Extraterrestrial Biological Entities', if you prefer), could build a vessel for space travel that could 'out-maneuver', or, 'get around', say, the speed of light, for one. They would be subject to the same distances and travel times that we would be subject to. Even if they were from some planet in the nearest star/planetary system, which is the Proxima Centauri system - and even if they could travel at the speed of light - it would take their spacecraft 4.2 years to arrive here at Earth - the same length of time that it takes light to travel that very same distance. 

So, let us take a look at light for just a minute: 'Light', is mass-less, neutrally-charged radiation from a particle called a photon. Photons are propagated through the vacuum of space in waves, at a constant speed, or, velocity. That velocity never varies, and we can use it to measure the distance to any celestial object by calculating the time it takes to travel from one place to another. The way we can measure these distances is by knowing the speed of light itself, which has been determined, and confirmed, countless times, to be exactly: 186,282.3976 mi/sec. Therefore: light from the moon takes 1.3 seconds to arrive at our eyes, here on Earth. Light from the sun takes 8.5 minutes. From the nearest star, Proxima Centauri, to our Solar System, the travel time for light is 4.2 years.  From those travel times, we can define the distance that light travels, in, say, one year's time - 5,874,601,670,000 miles. This is where we get the term light-year (LY) from. So, one light-year (LY) = 5,874,601,670,000 miles. The term is used as a measure of distance, rather than of time, for obvious reasons. And, as if that weren't bad enough - the next closest star hosting a known planetary system, is Fomalhaut. Fomalhaut ('foam*a*low'), is 25 LY's away. This means that our brave little aliens - in their very special (and, very impossible) light-speed-traveling spacecraft - would take 25 years to get here! After Fomalhaut, comes Pollux, at a distance of 34 LY's, and then, Algieba, at 126 LY's, way out there in interstellar space. There are many, many more stars beyond 126 light-years, this is true, but: nothing in the universe can travel at the speed of light, except light; that speed limit is reserved - for EMS radiations, only.**

The reasons for this are far too involved to get into in this limited space, so, as I had implied, earlier - I won't. You'll have to take my word for it. Violation of these restrictions (where the violation would exist, hypothetically, only), would bring on all kinds of impossible, even, laughable consequences; for example, infinite length-contraction and infinite mass, to name just two. Length-contraction and mass increase are two, verified relativistic effects from General Relativity. They are very real - and, they are problematic to mess with - so we're staying away from them. In short, anyone else out there is limited to the same physical restrictions, as ourselves.

The top speed that any of our manned spacecraft has ever achieved is about 26,000 mph - that's, one hour, to travel 26,000 miles. That's pretty darned fast, right? Nevertheless, in one hour light will travel 670,000,000 (670 million) miles. So, let's cut our 'little alien friends' some slack, and say that they have built a spacecraft that can travel 100 times the speed of our own. That will give them, a top speed of - 2,600,000 mph! Now, I've calculated it all out, so, I'll skip all the math here, but it's going to take those guys - 11,151 years to get to Earth - from the very closest star!  And if they're from Fomalhaut, it'll take them - only, 44,604 years - to get here!  And if they intended on going back home - they'll need an additional 44,604 years for the return trip! (Are you seeing the collective problem here?) Not a good position to be in, for interstellar space farers, to say the least.

Next item up for attack:

2) The unreliability of 'eyewitness' UFO reports Most people don't spend much time, on any given night, staring up at the sky. They might notice the moon and stars, an occasional meteor, or, a falling star - but that's about it. But, astronomers, typically, spend many hours on any, given, clear night peering intently into the sky. Not only are they in, direct, visual contact - night after night, year after year - but, they also have highly sensitive instruments, trained in various sectors of the celestial sphere.

I have never known any astronomer to file a UFO report - or, even, have had a sighting. Why should this be, when, so many others have?! The answer is not that astronomers are involved in some kind of UFO/conspiracy cover-up (if they were - I would have spilled the beans a long time ago). No; there is no need to be. You can't conspire about something that, you understand, does not exist. Moreover, unlike so many others, when it comes to strange-looking objects in the night sky, the astronomer has seen it all. She/He understands the many kinds of objects that the night sky has to offer, which, the typical layperson, couldn't identify if their lives depended on it.  I really don't mean to sound so harsh, but, that's a harsh truth - and I've heard all kinds of stories, misrepresentations, and misinterpretations. The problem that we astronomers have with this, is, that so many people think they can.

There are many, many celestial phenomena that the average layperson has never or, possibly, will never experience, such as, bolide or fireball meteors - especially the rare, larger asteroid fragments. Back in April of 1966, a large, iron asteroid fragment, had entered the atmosphere, at a shallow enough angle that its long flight through the thickened air slowed it considerably. Anyone not familiar with such a sight could easily have mistaken it for a burning aircraft. The 15ft.-diameter chunk of space-iron, which, emitted, glowing green and yellow at its leading edge, or, 'head', took about 45 seconds to cross the sky, from horizon to horizon, moving parallel to the thickened column of air hugging the Earth's surface at such a low angle. The object left a trail of glowing, orange fragments, along with its path - coupled with a wide corridor of white smoke, which I could trace all the way back to its point of origin (exclusive to my position). Measurements taken from Harvard College Observatory of the flight path of the object determined that it was 160 miles, due West, of my position on Cape Cod, and 60 miles in altitude, when it entered the atmosphere moving northwards, over New Jersey.  Then the rough, melting, mass of rock and iron, 'skipped' back out of the atmosphere, somewhere over Ontario, Canada. Sightings of asteroid passages of this magnitude are very rare; typically, a once-in-a-lifetime event. I was very fortunate to have seen two of them, as well as, the following, aging Earth satellite. 

In late July of 1979, I was spending the afternoon at Quissett Harbor, when I was treated to a replay of the 1966 asteroid flight. Low over the treeline, at the northwest horizon, there appeared a brilliant, blue-white object about the size of the full moon moving towards the southwest at an elevation of about 40 degrees. The object produced a long, white train of smoke behind it, which I was able to trace back to its point of origin. The object moved slowly across the sky at about the same velocity as that of the '66 fireball. I later learned that it was a large' chunk' of the Skylab, orbiting space station, which had suffered orbital decay that afternoon and plummeted through the atmosphere, at a moderately low angle, and ended up - in pieces - in the Australian Outback.  And there's more confusion in the sky: planetary groupings, conjunctions, opposition, some of which, even include the moon; comets, asteroids, satellite panels, and, antennae flares, the International Space Station, and, even, 'stationary meteors' (I've witnessed exactly one case of the latter). 

My point, is, that these, admittedly, spectacular events are very, very rare and could confuse anybody that didn't have a background in astronomy, and meteorology - and that includes pilots.  Aircraft pilots have it particularly tough when it comes to identifying objects in the sky that they aren't familiar with. One of the reasons for this is a lack of depth-of-field, or, an inability to determine an unfamiliar object's size, distance, and proximity, for want of a familiar reference point, or, a familiar object to compare with. This is because 'binocular vision, or, the 3-D, or, 'stereo' aspect of an object, beyond about 50 feet, is lost. This is the distance at which camera lenses become, 'fixed', at infinity. The 3-D effect is lost at that point and the brain's ability to judge an object's relative distance, relative velocity, or, even its dimensions, is lost unless the object is one that the viewer can recognize, and therefore, its dimensions are recalled to memory. Even then, relative distance and relative velocity are judged - not by a vision, per se - but by the observer's familiarity with the object. 

Aside from those celestial and meteorological surprises, and at least as important, is the subject of visual phenomena. For example, small, star-like points of light when seen in the sky, against a dark background, can produce, physical, and visual phenomena like the one that I experienced, one night, in my younger days, while watching the stars at the beach with my brother... Standing, facing the southern horizon and opposite our positions on the beach, we noticed a 'star' that was moving very slowly along the horizon and toward our right. After several minutes, it became apparent that the 'star' had a second component to its motion; it was moving toward us as well. After about another minute, it grew much brighter, and larger, and then -- began to sway, slightly -- back and forth, like a pendulum! We both saw this. At the same time. And at that point, I said to my brother, "Are you seeing what I am?!"  He answered, "You mean, it's wobbling!?"  Yes, that's what we saw all right. Meanwhile, there was no sound, whatsoever. Knowing that this was an impossible feat, for any conventional aircraft, and, that it broke, probably several of Newton's Laws of Motion, I then, yelled to my brother - of all things - "let's ditch into the dune grass - fast!"  Immediately after those, "out-to-lunch" words of wisdom, left my big mouth - we both heard the tell-tale, unmistakable - "thwup, thwup, thwup, thwup, thwup, thwap, thwap, thwap, thwap" - of approaching, doppler-compressed helicopter rotor blades....and then, we went home. And we didn't mention it, to anyone - ever again.

This common, but typically unrecognized, visual 'mirage' is called the 'pendulum effect'. It's just one of many possible anomalies of the human, eye-brain interface. There are others (some, you wouldn't believe!), like a  type of image 'flicker' that can cause a seizure in certain, affected persons. And there are others, even some that you have, likely, unwittingly experienced, at one time or another. For more enlightenment, see: http://onlinelibrary.wiley.com/doi/10.1113/jphysiol.1977.sp011686/full

On any given day, there are around 200 reports of UFOs, around the globe. And there are also those who have a tendency toward 'conspiracy theory out there, as well. Current television, 'documentary'-style programming which focuses on ancient alien visitation, and the like, are presented in serial form. They are able to continue on, and on, and on - only because they have nothing of import to present. Speculation is, seemingly, blissfully infinite. An important point once made by the late, Carl Sagan, very simply, states: "Extraordinary claims require extraordinary evidence"; and that - is the missing component in the data from those who make such claims as, possessing 'proof', of flying, extraterrestrially-piloted, vehicles/crafts, etc., over the skies of Earth. The 'proof' - in any form - of visitation by beings from other worlds, simply, doesn't exist. And, not to burst anyone's bubble - but, here's a little quote of my own: "In Science, you go with what you've got - not, with what you'd like to have".

So, I feel that I'm safe in saying, that, our skies are not full of the alien spacecraft, and their pilots, that most witnesses of 'UFOs' believe there to be. If and when that situation ever changes - and it is, hypothetically, entirely possible - it'll be a different story. But for the moment, the reigning consensus on whether or not we're being visited by beings from other worlds, by those who know best (the Astronomers), is, a big, fat "No".  **(This applies to all forms of radiation in the Electromagnetic Spectrum, including radio waves, microwaves, infrared light, visible light, ultraviolet light, x-ray, and gamma-ray radiations; all, are forms of light.)

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LHS 1140b - A Super-Earth in the Habitable Zone

We're getting our first good characterizations of terrestrial exoplanets lately. First, news broke of a possible planet around the nearest star to our Sun, Proxima Centauri. Then, we explored TRAPPIST-1, a mini solar system just 39 light-years away. Now, researchers from the Harvard-Smithsonian Center for Astrophysics announced the discovery today of a possible super-Earth orbiting an M-dwarf star just 34 light-years away. The discovery was published in the April 20th Nature.

An artist’s impression of exoplanet LHS 1140 orbiting a red dwarf star 41 light-years distant. ESO/SpaceEngine.org.

LHS 1140b is a tantalizing find. It is a cool, red host, LHS 1140, contains only 15% of the mass of our Sun and is at least 5 billion years old. The planet passes in front of its star once every 15 days as seen from Earth. Jason Dittman (Harvard-Smithsonian Center for Astrophysics) and the team combined discovery data from the MEarth project with radial-velocity measurements from the High Accuracy Radial velocity Planet Searcher (HARPS) survey.

The high-resolution follow-up observations enabled researchers to calculate the planet's orbital parameters and physical characteristics to a high degree of precision: The super-Earth, containing between 4.8 and 8.5 times Earth's mass, orbits just 0.09 astronomical units from its primary (almost a quarter of the average distance between the Sun and Mercury). The planet spans around 1.4 Earths. Combine its mass and radius and you'll calculate an incredibly dense 12.5 g/cm3 — the planet has more than twice Earth's average density!

Though red dwarfs are often tempestuous flare stars — a strike against life on any orbiting worlds — they're also long-lived and miserly in terms of energy output. These cool stars are expected to shine for trillions of years, longer than the present age of the Universe. That's a plus in that it gives ample time to get the engine of evolution going.

Read Full Source Article at http://www.skyandtelescope.com/astronomy-news/welcome-lhs-1140b-super-earth-habitable-zone/

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Time Troubles

I just calculated something out, and the result, well, is rather depressing... This is a photo of a portion of the Milky Way galaxy. Each dot in the photo is a star. More than 50% of all stars have planetary systems such as our Solar System. The nearest star to Earth is Proxima Centauri, one of three stars in the Alpha Centauri system. Proxima is 4.2 light-years away. There are 5.8 trillion miles in one light-year (or 5.8 thousand billion, or, if you prefer, 5,800,000,000,000), so we're dealing with about 25 trillion miles.

A view of the Milky Way toward the  constellation 
Sagittarius.  Source: Wikipedia.

OK, That's bad enough. But let's say we decide to send an astronaut to Proxima Centauri, in the fastest rocket, at the fastest manned flight speed we've been able to attain (that would be the Saturn V, a 3-stage booster used for the Apollo program - a top speed of 26,000mph). Now, even if we could send that astronaut at the speed of light (exactly 186,282.3976 miles per second, in vacuo), it would take her (or him), 4.2 years to complete the trip as measured by an observer on Earth (because of the relativistic effects of time dilation, only a few days will have passed, as judged by the astronaut - but we're not going there! - not here - that's another story, for another time). But, now for the sad part...

At 26,000 mph, 0.000037% the speed of light, the trip would take 116,000 years. That's one-way. Our astronaut would be, long ago, fossilized. Time dilation is negligible here, so we don't need to factor it in at such low velocities. One of the nearest stars with a known planetary system is around 15 light-years. So, if we have cosmic relatives somewhere out there within that range, the chances of meeting up with them are absolutely nil. These distances and times involved are the reason most astronomers don't believe in UFOs, or that we're being visited by extraterrestrials. YES, WE DO BELIEVE they exist, but not that we're being visited by them on any regular basis. The situation isn't much better with radio communications. Even though radio waves travel at the speed of light, transmission to any hypothetical beings in, say, the Fomalhaut planetary system will take 15 years. That's one-way. Telepathy, should it prove to be viable, would be much more economical, assuming it to be instantaneous. Another plausible answer might be to travel through wormholes, to beat the clock, but, for now, they're hypothetical. Other than that, due to the restrictions on speed, we may never meet anyone else; we might always be alone - surrounded, perhaps, by a myriad of Celestial Peoples - and yet alone, regardless.

Dale Alan Bryant
Senior Contributing Science Writer

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