Talk:10 Hygiea
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[edit] Mass
I have a newer source listing Mass ≈ 8.07×1019Kg [1]. I will wait 1 week for feedback before applying the updated information. Abyssoft 04:59, 4 September 2006 (UTC)
- This is a very interesting reference. Great that you found it ; Here is what a search in PDS and ADS for other mass estimates turned up:
| Author | Year | Mass (in Solar mass × 10-12) | note | link |
|---|---|---|---|---|
| Scholl et al | 1987 | 47 ± 23 | [2][3] | |
| Goffin | 1991 | 49 ± 21 | [4][5] | |
| Kuznetsov | 2001 | 17.4 ± 6.8 | repeated by Kochetova | see Kochetova |
| Michalak | 2001 | 55.7 ± 7.0 | the bolded "weighted mean without 7 Iris" on p 705 | [6] |
| Kochetova | 2004 | 50.1 ± 4.1 | reference mentioned on the new webpage | |
| Chesley et al | 2005 | 45.4 ± 1.3 | [8] | |
| Chernetenko et al | 2005 | 40.6 ± 1.9 | newer calculation on the web | [9] |
- Apart from Kuznetsov who was out of line for some reason, the rest seem to fall in the same ballpark so the rough mass is at least pretty confident − unlike some of the asteroids.
The new reference appears to give the second most precise value, but the Chesley calculation gives by far the smallest error so I think we should keep that one;The Chelsey number also appears the most trustworthy by itself because it is based on only a single very close encounter unlike the others which average over a bunch of distant encounters that singly give a very imprecise values. In my opinion, the advantages of a paper that bases itself on just one encounter is that- there is less chance that the perturbed body were also later/earlier perturbed by other asteroids, throwing the mass estimate off
- one imagines that the data there was much more carefully inspected for anomalies (that may indicate a systematic error) than a big bulk calculation over many bodies.
- See e.g. the influence of the 7 Iris perturbation in the Michalak paper.
:I suggest to reference the new Kochetova paper along with Chelsey in the article, but to keep the current Chelsey value and add in its error estimate. In fact I'll do that now provisionally. :Ah, and Kochetova looks like it could be a real good reference for a bunch of other asteroids. Deuar 22:29, 4 September 2006 (UTC)
- Sorry, i've just realised the web page had newer calculations than the paper. So, Chelsey (current value in the article) and the newer web value of Chernetenko+Kochetova+Shor give by far the smallest error estimates, but worryingly they don't overlap. I suggest averaging these two best estimates and quoting an error in the article that roughly covers both cases. That would be 43.0 ± 3.7. Looks like a really good reference :-) Deuar 23:02, 4 September 2006 (UTC)
[edit] Images?
This page desperately needs an image...even if it is just a picture of it in a starfield. 70.177.71.206 17:28, 9 September 2006 (UTC) Possible Image per request @ http://www.ipac.caltech.edu/2mass/gallery/hygatlas.jpg Permission needs to be acquired first.
- Permission is already given. Going up one level, at the bottom of the page: "Please note: The images in this gallery are released into the public domain. If any image or images are redisplayed or reproduced, please accompany the image or images with the following acknowledgment: "Atlas Image [or Atlas Image mosaic] obtained as part of the Two Micron All Sky Survey (2MASS), a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation." If pressed for space, this acknowledgment could be shortened to, e.g., "Atlas Image [or Atlas Image mosaic] courtesy of 2MASS/UMass/IPAC-Caltech/NASA/NSF." However, all or part of the full acknowledgment is preferred. This is the stated policy of 2MASS."Michaelbusch 02:44, 10 September 2006 (UTC)
