In Search Of the Vulcans

jonerik writes: "No, not those Vulcans. The BBC has this article on the Southwest Research Institute's (SwRI) search for the Vulcanoids, a belt of perhaps a few hundred small asteroids (perhaps between one and 25 kilometers in diameter) theorized to exist inside of Mercury's orbit around the sun. Because of their closeness to the sun and small size, the asteroids - if they exist - would be hard to observe from the ground. To that end, a NASA F/A-18 is being used to conduct a search 'of the twilight sky near the Sun that is far darker and clearer than can be obtained from the ground,' says Dr. Dan Durda of SwRI. According to the article, 'The camera used in the latest search...is trained on the region of space close to the Sun after the star has dipped below the Earth's horizon. The camera grabs twilight images at a rate of 60 frames a second.' The researchers hope to have a better idea of whether or not the Vulcanoids exist in another month or two."

Comments

looking for Vulcans during solar Eclipses

[chongo]

For the past several years, astronomers have been looking for Vulcans during total solar eclipses. The hope is to catch a Vulcan asteroid on either side of the Sun during totality.

Photos are taken during totality. One camera is stationed near the beginning of the totality path. A few more are placed in various places along the path. A final camera is placed near the end of the totality path. Typically there is about 2 to 3 hours time between the 1st and last camera images.

The images are searched for faint moving objects that are in orbit around and near the sun.

Thus far, a few comets have been detected but no Vulcan asteroids have been found.

Re:Hey

[dpp]

I thought longer exposure times, sky conditions and a stable camera were key in astrophotography. If I'm wrong please correct me, but mounting a camera on an f-18 dosen't sound like good practice.

According to the SWUIS page the 60 fps rate of the camera is used for jitter compensation, so presumably the fast frame rate is quicker than the characteristic timescale of the aircraft motions.

An aside: for the larger aircraft-borne telescopes like the Stratospheric Observatory for Infrared Astronomy (SOFIA) the telescope is "as stable as a mountaintop telescope sitting on a 10 meter cement foundation" according to the FAQs. From that page:

So how do you do this? First, you isolate the telescope from the airplane by mounting it on a spherical pressurized oil bearing. The plane shakes and quakes, but the telescope doesn't feel it. Second, you direct the wind away from the telescope by shaping the side of the airplane so as to deflect it, and install a little deflector fence on the edge of the telescope cavity as well. Third, you stabilize the telescope against sudden motion (wind does get through) by spinning three orthogonal gyroscopes which are rigidly attached to the structure, and fourth, you steer the telescope so as to keep it steady, by tracking a distant star and giving the telescope magnetical nudges to point it toward a fixed direction.

Why mount of an f-18, was Re:Hey

[chongo]

The f-18 is able to chase/extend the time it spends in twilight. At middle North America latitudes (say 40 Deg. North) the twilight shadow moves over the ground at about 1275 km/hr (~793 MPH), well within reach of an f-18. A scope on the f-18 can stay within the twilight shadow for an extensive period of time.

As for the concern about stable cameras, NASA has been flying mounted scopes for some time. The guidance and anti-vibration systems are good enough to conduct real astronomy. In fact, craft such as SOFIA are pushing the technology even further. Yes, scopes on aircraft is outstanding practice.

One might, however, ask if the glare of the twilight combined with observing low to the horizon will impact their ability to find Vulcans. Compared to the Eclipse method, the f-18 observing conditions are poor (low in the horizon, reduced image brightness, glare from the Sun that just set, dust, etc.). On the other hand the number of minutes to observe during totality (see my other posting on this topic) are limited. A single f-18 run can rack up more minutes than ground based eclipse imagery can in a decade.

Better would be to fly cameras on an f-18 or Concord or SR71 in the Moon's shadow during a total eclipse. You can get the best of both worlds.

Better still would be to observe from space with a special telescope that can take images near the sun.

NOTE: Scopes like the Hubble cannot look too close to the Sun for obvious reasons. That is why you have and will never see a Hubble image of Mercury, let alone Vulcan asteroids.

Craft such as SOHO were not designed to look for Vulcans because they, if they exist, are too dim.

Vulcan asteroids, if they exist, are very dim. Bright Vulcans would have been spotted long ago during some eclipse or if nothing else during the extensive Vulcan search in the late 1800's.

Each method as its +/-'s as well as cost tradeoff. I wish this new Vulcan program all the best in the hopes that they can do what others have failed to do so far.

Re:Why do this now?

[EvilBastard]

Why do this now ?

Because they are there.

* Maybe they'll be stable enough to mount a nice in close power station without having to worry about Mercury's gravity well

* Maybe observing their orbits could point to some more information on the GU theory

* Maybe they could lead to some more theory on planetary formation with formation of planets close to stellar bodies

* Maybe the knowledge gained from this can lead to new designs on high-altitude fast turnaround observation of objects coming at us from the sun (Like, the last two near-miss asteroids)

* Maybe they are completly unremarkable chunks of stone, worth two or three papers and then forgotten about.

It's a ground based observation at objects too close to the sun for most observations, done on the cheap with minimal new hardware designs. I'd be very suprised if the total budget for this was much over 3 or 4 million total

The things you want NASA to do ? Guess what - they are already doing them. It's just they like doing a wide variety of different things, because you never know when you'll find something interesting in an unexplored area of science.