Dear Krisztian, Med, all,

?

It’s still quite early in the game, but, indeed, this object does look interesting. There does seem to be some similarity to the orbit of the Daylight Comet of 1910, although the difference in the ascending node (as of right now, anyway), would seem to preclude a relationship. But, we’ll see what the future holds . . .

?

I succeeded in getting some images last night via LCO-SAAO. The appearance is almost stellar, although it does seem to be slightly diffuse when compared with stars of similar brightness. I’ve reported it to the MPC (and CBAT) as a “possible” comet.

?

If something like the present orbit holds, the post-perihelion viewing geometry (when there would likely be the most dust tail development) favors the northern hemisphere. For a while, the phase angle is somewhat high, so possibly some dust tail (if there is one) enhancement from forward scattering. And – yea! – it’s in the evening sky. On the other hand, with this small a perihelion distance, it would have to survive perihelion to put on any kind of show, and that is always problematical.

?

Again, we’ll just have to wait and see. I’ll probably try imaging it again in a day or so.

?

?

Sincerely,

Alan

?

Dear all,

?

Here is one of the images I obtained last night from LCO-SAAO. 180-second exposure with a 35-cm Cassegrain; cropped, but otherwise no processing.

?

I have another set of images ordered up for tonight.

?

?

Sincerely,

Alan

?

Dear Krisztian, Med, all,

?

It’s still quite early in the game, but, indeed, this object does look interesting. There does seem to be some similarity to the orbit of the Daylight Comet of 1910, although the difference in the ascending node (as of right now, anyway), would seem to preclude a relationship. But, we’ll see what the future holds . . .

?

I succeeded in getting some images last night via LCO-SAAO. The appearance is almost stellar, although it does seem to be slightly diffuse when compared with stars of similar brightness. I’ve reported it to the MPC (and CBAT) as a “possible” comet.

?

If something like the present orbit holds, the post-perihelion viewing geometry (when there would likely be the most dust tail development) favors the northern hemisphere. For a while, the phase angle is somewhat high, so possibly some dust tail (if there is one) enhancement from forward scattering. And – yea! – it’s in the evening sky. On the other hand, with this small a perihelion distance, it would have to survive perihelion to put on any kind of show, and that is always problematical.

?

Again, we’ll just have to wait and see. I’ll probably try imaging it again in a day or so.

?

?

Sincerely,

Alan

?

Forgot to add: image was taken on May 25.13 UT.

?

Dear all,

?

Here is one of the images I obtained last night from LCO-SAAO. 180-second exposure with a 35-cm Cassegrain; cropped, but otherwise no processing.

?

I have another set of images ordered up for tonight.

?

?

Sincerely,

Alan

?

Dear Krisztian, Med, all,

?

It’s still quite early in the game, but, indeed, this object does look interesting. There does seem to be some similarity to the orbit of the Daylight Comet of 1910, although the difference in the ascending node (as of right now, anyway), would seem to preclude a relationship. But, we’ll see what the future holds . . .

?

I succeeded in getting some images last night via LCO-SAAO. The appearance is almost stellar, although it does seem to be slightly diffuse when compared with stars of similar brightness. I’ve reported it to the MPC (and CBAT) as a “possible” comet.

?

If something like the present orbit holds, the post-perihelion viewing geometry (when there would likely be the most dust tail development) favors the northern hemisphere. For a while, the phase angle is somewhat high, so possibly some dust tail (if there is one) enhancement from forward scattering. And – yea! – it’s in the evening sky. On the other hand, with this small a perihelion distance, it would have to survive perihelion to put on any kind of show, and that is always problematical.

?

Again, we’ll just have to wait and see. I’ll probably try imaging it again in a day or so.

?

?

Sincerely,

Alan

?

Hi Roberto, all,

?

Astrometrica automatically gives FWHM measurements, but I usually don’t pay too much attention to these, especially since the MPC’s “Report Cometary Activity” form requests full coma diameters and specifically states “not FWHM.”

?

I took an additional set of images last night, coincidentally at almost exactly the same time as Jordi’s image that he posted. The appearance on my images is very similar to the appearance on his, i.e., condensed, but slightly and definitely diffuse. I’ve now reported it to the MPC as “definitely cometary,” and I see that it has now been moved to the PCCP.

?

As Maik has pointed out, the orbit looks reasonably solid now. It’s not quite as “interesting” as some of the initial orbits, but still looks pretty good. The big question, as he states, is whether or not it will survive a perihelion passage this close to the sun. Hopefully it will undergo an upsurge in activity as it approaches perihelion, and perhaps it might turn out to be “old” in the Oort sense; if all this happens, then we northerners might still be in for perhaps a somewhat decent show, although probably not any kind of “Great Comet.”

?

Sincerely,

Alan

?

Hi Roberto, all,

?

You are correct, of course. Up until now, and in light of the MPC’s requirements, I just haven’t considered that a high enough priority to acquire the necessary software (other than Astrometrica, which, as you, I utilize for astrometry). If I do decide to pursue things along those lines in the future, I might consider getting those packages.

?

I note that, concerning the object that precipitated this discussion (A11nyuL = C/2021 K5), the next set of images I took did definitely show it as cometary, and I reported it as such. I’ve seen images taken by other observers (notably Taras Prystavski on May 28) that show its cometary nature rather well.

?

And, while on this topic . . .

?

We’ve had discussions here and on another forum (i.e., Facebook) about the potential cometary activity I possibly imaged on (308607) 2005 WY3. There were a FWHM analysis reported on FB that at least was somewhat suggestive of a cometary nature, although as was the case with the various images I took of this object, none of this is anywhere near conclusive. (308607) is now just a little over two weeks away from perihelion passage, but unfortunately is too low for me to get with LCO (present elongation 43 degrees, and decreasing). Yes, this is a hint – a plea – for anyone with suitable equipment to try to verify, or conclusively dis-confirm, any possible cometary activity on this object before it gets too low for anyone to access.

?

I’ve also been imaging (6144) Kondojiro – which is now less than a week away from perihelion – on a semi-regular basis, my most recent images being from last night. Totally stellar on all images . . . For what it might be worth, the FWHM measurements by Astrometrica on last night’s images are essentially identical to those of stars of similar brightness.

?

?

Sincerely,

Alan

?