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NASA's WISE Space Telescope Jettisons its Cover12.29.09

WISE is scheduled to begin its survey of the infrared heavens in mid-January of 2010.

Really looking forward to the asteroid, brown dwarves results. And the unexpected!


Always a relief to hear that the last critical deployment event for a mission was successful! smile.gif

Here's to seeing the unexpected...we always do.

EDIT: First guess at the unexpected: Spotting the Solar System's "debris trail". Given the fact that matter is pretty sparsely distributed in interstellar space, there should be a fairly constant escapement of micron-sized dust along with all kinds of molecular species that should stand out by contrast.

This outflow of course would be strongly influenced by the heliopause & other effects...but it would be interesting & scientifically useful for many reasons if it could be observed & characterized.
First light
"More soon, including a comparison of this new WISE image vs. the old catalogs it will replace: COBE and IRAS."
Emily has posted the WISE news regarding the team's first asteroid discovery...

Exciting.... and open the WISE image... expand it and look at ALL those little red dots...lots and lots of little red (which means cool) dots.

Any brown dwarfs in there? I tremble!

Wow, there are lots of faint red dots in the image. However, I have a question on the number of asteroids Wise will find. If the nominal mission is 200 days, and is expected to find hundres or thousands of asteroids, then that is 1/day or 10/day for 200 or 2000 asteroids. From first light to first asteroid was 6 days---that is about 33 in 200 day mission. What am I misunderstanding?
The time lag due to the need for follow-up observations prior to announcement?
Greg Hullender
Makes sense. Takes time to settle into a new routine, work out the bugs, fill the pipeline, etc. I'll repeat my concern that some of these objects will end up being hard to follow up on. Either because there are just too many for the available ground instruments or because they can't be seen from the ground at all.

But we'll see.

There's interesting discussion of these issues going on in the Minor Planets Mailing List by people who (unlike me) actually know what they are talking about in terms of astrometry and followup.
Greg Hullender
Thanks, Emily. One post there, from Richard Kowalski with the Catalina Sky Survey at the University of Arizona seemed especially helpful.

In particular, he quoted Tim Spahr, Director of the Minor Planet Center as saying:

"It seems there is some information lacking that will help the understanding of the WISE mission a bit better. First and foremost, when fully operational, the spacecraft will observe each object ~10 times over ~1.0 days. Thus, each object observed will be of 'designatable' quality. Further, NASA has funded various projects to do follow-up specifically of their NEOs. At 1-2 new NEOs per day, there is an excellent chance that most NEOs will be followed-up with existing resources. Lastly, and this seems lost on nearly everyone, the existing follow-up capabilities are really staggering now. H55, G96, and 291 observe nearly every single new NEO discovered. It is really rather spectacular. So my feeling is really that WISE will probably not generate a big bunch of things with little or no information.

"On the MBA side, the MPC expects to link most WISE discoveries with observations from G96, 691 (also funded to support WISE directly), and 703. But even if we don't, there's nothing wrong with a bunch of 2-night objects in our files, waiting for other identifications at other oppositions in the future."

That pretty much answered my questions.

Thanks again!

QUOTE (Greg Hullender @ Jan 25 2010, 10:28 AM) *
H55, G96, and 291 observe nearly every single new NEO discovered.

Pardon my ignorance, but who are these numbers?
Those are observatory codes; if you read the MPECs you'll see the codes given next to the observations used for discovery and astrometry. There is a unique one issued to every telescope who does minor planet astrometry.
291 is the 1.8-meter Telescope of the Lunar and Planetary Laboratory, at Kitt Peak operated by the University of Arizona, Tuscon

G96 is a 60" reflector at the summit of Mt. Lemmon North of Tuscon

H55 consists of the 32" and the 24" telescopes at the Astronomical Research Observatory, Charleston. Illinois.
These post and links answer my questions as well. Followup on the WISE findings is complex and will involve lots of observatories--guess I wasn't the only one slightly confused by the initial reports--more information helps a lot.
Greg Hullender
The best part, for me, anyway, is that they really do have a wise and well-thought-out plan for following up on all potential asteroid observations. Now I'm ready to sit back with some popcorn and watch the results come in!

QUOTE (Greg Hullender @ Jan 25 2010, 08:53 PM) *
Now I'm ready to sit back with some popcorn and watch the results come in!

One hopes we don't watch the asteroids come in.... laugh.gif

Thanks for the clarification Emily and Dan!
WISE has found its first new comet!

QUOTE (elakdawalla @ Jan 25 2010, 10:42 PM) *
Those are observatory codes; if you read the MPECs you'll see the codes given next to the observations used for discovery and astrometry. There is a unique one issued to every telescope who does minor planet astrometry.

Full list of observatory codes can be found at
NASA has recently released a sample of the first WISE images, showing everything from Comets to Galaxys.

Steve M
More than 1/3 of the mission completed!
I noticed that the north and south pole of its orbit satellite photographs over each period of around its orbit. I.e. two sites of the sky the total area of 1.28 square degrees to be obtained 4320 images. Do you plan to search for transiting planets in these data?
For comparison with the same area COROT field of about 2 square degrees, and time monitoring of up to 5 months.
Greg Hullender
Well, I'm not sure how useful "Warm Wise" would have been anyway. It'd be nice to see how much they're finding in the four frequencies they have vs. the two they'd have left (after the hydrogen is gone).

I note they're 2/3 done with the first pass now.

Still no reports of brown dwarf companions to Sol.

Greg Hullender
Just past 75% coverage now.

No press releases since February 11, when they reported a new comet. Wonder why not?

Ron Hobbs
JPL posted a news item on Tuesday, WISE Makes Progress on Its Space Rock Census. There is an attendant video with an interview of the PI of NEOWISE, Amy Maisner, that is well worth catching. Space Rock Census

According to the feature, 11,000 of the NEOs and asteroids it has observed are new.
QUOTE (Ron Hobbs @ May 26 2010, 02:55 PM) *
11,000 of the NEOs and asteroids it has observed are new.

Yeah...what Dan said!!! blink.gif

That's absolutely mind-boggling. I was expecting a few hundred, maybe a thousand.
Does anyone know what the statistically predicted numbers of various classes of objects were, and how those numbers are shaking out thus far? Or will we have to wait for the "paper?"
If we could see, with our own eyes, all the crap flying about Out There, we'd never dare look at the sky, would we..? ohmy.gif
WISE satellite already spots two brown dwarfs
One of the brown dwarfs, dubbed WISE 2, appears to be as cold as any that are known. It may even be colder, Wright said, than the brown dwarfs recently found by the UKIDSS survey, which are estimated to be in the neighborhood of 500 Kelvin, but the exact temperature of WISE 2 is uncertain (as are the temperatures of the UKIDSS objects). WISE 1 is a bit warmer, Wright said: "We think this is about an 800-Kelvin object."

Wright later said that whereas the spectra of WISE 1 and WISE 2 are unambiguous, the spacecraft has found many more objects that may also be brown dwarfs. Confirmation of those will await follow-up observations, which the group has proposed on the Spitzer Space Telescope. Distances to the two new brown dwarfs are not known, Wright added
"....Wright said, than the brown dwarfs recently found by the UKIDSS survey, which are estimated to be in the neighborhood of 500 Kelvin...."

Just the right place to bake a pizza!
Greg Hullender
I'm surprised they don't have estimated distances to the Brown Dwarves. Much like Red Dwarves, I'd expect they must be fairly close to be visible at all, even by WISE.

Perhaps there hasn't been enough time yet to get good parallax observations on any of them?
then, why is the mission nearly complete?
Good point. We don't know when they were identified, though, nor if there have been any follow-up observations (presumably from ground-based assets.)

Given the limited operational lifetime of WISE I'll bet that they're in straight data acquisition mode all the way to the end, and sifting through the torrent is secondary at this point. There's probably no chance to take another look at almost anything.
QUOTE (nprev @ May 30 2010, 11:29 PM) *
Good point. We don't know when they were identified, though, nor if there have been any follow-up observations (presumably from ground-based assets.)

Something actually mentioned [warm] Spitzer would be used to look at the Brown Dwarves.
Greg Hullender
QUOTE (nprev @ May 30 2010, 07:29 PM) *
There's probably no chance to take another look at almost anything.

Except that asteroid observations have to be followed up on almost immediately. It does seem they're doing that.

I was interested that they hadn't found anything so dim in other frequencies that it couldn't be observed by some other instrument. That certainly suggests we ought to be able to get parallax measurements within a few months.

Holder of the Two Leashes
There have been some cases of follow up observations of asteroids being made months later (blast from the past), and a few cases of WISE making all the observations necessary by itself to designate an asteroid (WISE only). Also a very few cases of finding an asteroid only with WISE data months after the observations (2010 AR85 is an example). Here is the link to the asteroid discovery page at the WISE website.

WISE asteroid discoveries Note that this is mostly for NEAs.

For parallax observations, WISE fortunately is always observing at right angles to the sun, so that even objects in the ecliptic plane will be observed at maximum angular displacement six months later. During the nine month mission about half the sky will be observed by WISE alone with parallax data points. Unfortunately, in most cases you will also need a data point at one year in order to subtract out the proper motion, which in most cases dwarfs the parallax. The mission will end after nine months. Follow ups will have to be with some other telescope.

Large proper motion itself might be the main indicator they are looking for, in order to find nearby objects (nearby in this case meaning stellar neighborhood).

A person at WISE outreach was kind enough to inform me that they can determine positional accuracy for stars to better than half an arc second. This is in line with the residuals I see listed on the asteroid reports from the minor planet center. So anything closer than, say, five or six light years should produce a measurable parallax, albeit with a fairly large error.
Greg Hullender
I see WISE is past 95% coverage now, so definitely into the home stretch. I also noticed that they managed to analyze the blob around the Galactic Core which had given them some troubles earlier. It looks as though they had some sort of outage a month or so ago, meaning there's a small stripe that they missed. Since that's in the last half of the sky, that means it won't get reimaged on the second pass. Pity, but it's still pretty impressive.

I note WISE is up to 97 reported discoveries now.

Including 13 Potentially Hazardous Asteroids (PHA). I don't see Torino numbers on any of these, so I'd guess there hasn't been time to analyze their orbits thoroughly.

Greg Hullender
With no special announcement, it seems WISE has completed its sky survey--minus those strips where the camera apparently went offline or something.

If wonder if there will be any big surprises during the next part of the mission, perhaps from noticing that something moved unexpectedly.

I recall reading that the aim is changed to avoid the moon when is at first and last quarter. I suspect they get picked up the next time the moon reaches those phases.
Greg Hullender
They updated the text on the page that shows progress. (Now at 99.5%)

They say the red stripes result from the moon-avoidance strategy. No mention of the off blue strip, but, somehow, they're covering it now, and they say they'll be at 100% tomorrow.

Some highlights:

more than one million images so far
more than 100,000 asteroids, both known and previously unseen
more than 90 new near-Earth objects
more than a dozen new comets
The first release of WISE data, covering about 80 percent of the sky, will be delivered to the astronomical community in May of next year.

Also today, they released a new pic of the Pleiades:

Cool stuff!


Greg Hullender
The WISE coverage map has become much more colorful:

I wonder what the "16x" factor means? Does it actually mean that the point was imaged on 16 different orbits?

I would have thought so - notice the density increasing to the poles. It would have imaged, roughly speaking, the same spot over the north pole every single orbit just about
It's my understanding that folks looking for planets, comets, KBOs, &c. don't observe high above the ecliptic so much, because of the lesser likelihood of finding anything there. I'm curious to see if WISE manages to snag some interesting findings, especially since it's got so much polar coverage.
There should be a higher probability it will be a comet if they find anything there.
It's also a higher probability it's a NEO. With modest inclinations, if they're close enough, they'll still appear at high angles to the ecliptic.
I find these informations on the comet section of British Astronomical Association, :
Jul 23 WISE discovers asteroid in retrograde orbit
Jul 30 WISE discovers short period retrograde asteroid

Any more informations about these discoveries ?
A short-period retrograde asteroid?

Wow. That might be the first such ever discovered, esp. if the orbit's anywhere close to the ecliptic plane. Hopefully more info will be forthcoming.
Holder of the Two Leashes
The July 23rd discovery was asteroid 2010 OR1, which has a period about 30 years and an inclination around 143 degrees.

The July 30th discovery most likely was actually a reobservation of asteroid 2010 LG61, which was discovered by WISE back in June, but whose orbit at the time was nearly impossible to fit properly. They originally thought it was very small, in a prograde Aten type orbit. WISE got an additional look on the 26th which finally got the orbit right. It is a much larger rock than they thought with a period around 19 years (this is short period?) and inclined 123.7 degrees.

I can find no other candidate for the July 30th asteroid.

These are impressive, but not record holders. Other examples would be the recently discovered 2010 EB46, found by the Catalina Sky Survey back in March, which has a period 16.7 years and an inclination of 156 degrees, both of which best 2010 LG61. Then you have 2008 SO218, which beats out 2010 OR1 both on period (23 years) and on inclination, which is 170.4 degrees and nearly in the ecliptic going backwards.
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