# Tag Info

## Hot answers tagged occultation

46

It's not very surprising that no Oort Cloud objects have been detected via occultations. They're extremely rare, even for our most advanced space-based observatories. According to Ofek & Nakar 2010, published about one year after the launch of Kepler, the telescope would be able to detect between $0$ and $\sim100$ occultation events of Oort Cloud objects,...

24

There were three attempts to measure Arrokoth by occultation, and the June 3rd attempt didn't detect anything. The July 10th attempt had a tiny blip, that appeared to be in the "wrong place", well away from the location that astrometry had predicted. The July 17th occultation was successful, it determined the shape and location well. Some thought ...

12

According to Wikipedia: A preliminary analysis of all collected data suggested that Arrokoth was accompanied by an orbiting moonlet about 200–300 km (120–190 mi) away from the primary. It was later realized, however, that an error with the data processing software resulted in a shift in the apparent location of the target. After accounting for the bug, the ...

9

Yes, but such an event would be very rare. Venusian transits last only about 7 hours, and there are only two in 113 years, So Venus is in transit for about 0.0015% of the time. So as a back-of-the-envelope calculation, you would need to see about 70000 eclipses before you had a combined transit/eclipse. There are about 2 solar eclipses a year, so you might ...

6

From the observer's point of view 1 million km away, the TNO's apparent angular motion is $$\mathrm{\frac{8~m/s}{10^9~m} = 8 \times 10^{-9}~rad/s = 0.00165~^\circ/h}.$$ Assuming that the observer at 18 billion km = 120 au is in a circular orbit around the Sun, the orbital period is 1203/2 = 1320 years, making the Sun appear to move the other way at \...

5

The search for sungrazing comets requires looking very close to the Sun for faint objects. This requires a chronograph and for faint objects is better done above the atmosphere. The SOHO spacecraft near the Sun-Earth L1 point does this nicely. Here is a GIF I made for this answer. In addition to some comets you can see Venus on its approach to occultation by ...

4

There are a number of terms for these things: conjunction: When two objects have either the same right ascension or the same ecliptic longitude (usually as observed from Earth). That is, they lie in (almost) a straight line from the point of view of the observer. In the case of the Solar System, such as when the Sun and Venus line up from the point of view ...

4

Pluto is actually smaller in diameter than Triton, and is also farther away, meaning that Triton covers roughly 1.4x (according to WA) the angle that Pluto does, making occultation that much more probable apriori, ignoring their actual orbits. In addition to the above, New Horizons recently observed Pluto's atmosphere with far more detail than what we can ...

4

Actually, the very first binary asteroid was discovered by stellar occultation in 1980. The evidence was rejected by the IAU, and wikipedia credits the first binary asteroid discovery to the Galileo spacecraft finding the moon of 243 Ida in 1993. The first moon of the well known asteroid 216 Kleopatra was observed through stellar occultation in 1980. From ...

4

Unfortunately, there was a server problem in the days leading up to the exciting Mars occultation. (It didn't matter to me because it was, unfortunately, cloudy where I live.) This description of the colored lines is from a temporary page provided by IOTA: The turquoise curves show where the disappearance or reappearance occurs at moonrise (left side) ...

4

For what it's worth, I just got a shot of what looked like a 5th Galilean moon near Ganymede tonight (from South Florida). Here's a quick, unprocessed image. I thought I was going crazy seeing an extra moon (in the correct plane) that kept showing up. But looks like it's HIP 99314 (2nd dot to the upper left of Jupiter).

3

The answer is a strong maybe. The International Occultation Timing Association (IOTA) produces predictions for such events. Their webpage Major Planet Occultation Predictions lists the occultation of HIP 99314 by Jupiter, but it does not list an occultation by its moon Ganymede. Date U.T. Durn Star Star Planet y m d h m ...

3

A lunar occultation of Venus happens when light from Venus can not reach the observer because the Moon blocks it. The simplest model for this would be to draw a line in 3D from Venus to the observer and detect when that line passes through some part of the Moon. However that doesn't take into account the time it takes for the light to travel from Venus to ...

3

Observing star occultations is dependent on the object passing in front of a star. During its short time in the inner solar system, ʻOumuamua didn't pass in front of a star (from the point of view of Earth) It is now beyond the orbit of Saturn. It became too dim for Hubble in about January 2018. There are no forecast occultations of any star (and its orbit ...

3

Is there a more rigorous definition of these three terms that distinguishes an eclipse from an occultation or a transit? Not quite rigorous, but Occultations refer to events where the intervening object's angular size is significant larger than is that of the more remote object, Transits refer to events where the intervening object's angular size is ...

3

Wikipedia lists some of the most farthest objects from the sun in the solar system. The third farthest object "Eris" was the subject of one of the most distant stellar occultations observed from Earth. From this occultation, its diameter, density and albedo was calculated. On 6 November 2010, Eris occulted a faint star (V $\sim$ 17.1) which was ...

2

Moon-Mars Occultations occur every 174 to 188 Days Average worldwide interval (based on 500 years) between occultations is 180 days. In a calendar year, zero to five occultations can occur. Annual occultation doesn't occur on average about once in 15 years. (Source) Moon will occult Mars 3 times in 2021. Here is the map

2

Does a lunar occultation of Mars happen twice a year? No, in the sense that the number of lunar occultations of Mars per year is quite variable and not always two. I do not have a reference handy, but I am sure that there are some years with no occultations. And we can see that in other years the number can be both less than and much greater than two: In ...

2

A VizieR query within 15 arcseconds of Buie's coordinates returns a 13th magnitude star, variously identified as: 2MASS 19042146-2035362 UCAC4 348-170642 Gaia DR2 4082342058110504064

1

Some of your description, and the answers to date, assume that Venus has to transit the Sun. That is not a requirement for the literal question "can lunar occultation of Venus occur during a solar eclipse". Likewise, the description says "three" events but only gives two conditions: Moon is at front of Sun and Venus is behind Moon. If you ...

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