IPB

Welcome Guest ( Log In | Register )

3 Pages V  < 1 2 3 >  
Reply to this topicStart new topic
(Paper) Evidence of a Jovian Mass Solar Companion in the Oort Cloud?
Greg Hullender
post Apr 28 2010, 09:26 PM
Post #16


Senior Member
****

Group: Members
Posts: 1010
Joined: 29-November 05
From: Seattle, WA, USA
Member No.: 590



QUOTE (Vultur @ Apr 28 2010, 12:29 PM) *
Presuming 20,000 AU, to get there in twenty years would require an average speed of 4740 km/s.

Note that 10,000 AU is about two light-months, and 30,000 AU is about half a light-year.

We're talking really, really far here.

--Greg
Go to the top of the page
 
+Quote Post
Stu
post Apr 29 2010, 05:34 AM
Post #17


The Poet Dude
****

Group: Moderator
Posts: 5548
Joined: 15-March 04
From: Kendal, Cumbria, UK
Member No.: 60



Great, something ELSE to add on to our Solar System Scale Model... !

smile.gif


--------------------
Go to the top of the page
 
+Quote Post
PFK
post Apr 29 2010, 09:16 AM
Post #18


Junior Member
**

Group: Members
Posts: 80
Joined: 22-May 08
From: Loughborough
Member No.: 4121



QUOTE (Stu @ Apr 29 2010, 06:34 AM) *
Great, something ELSE to add on to our Solar System Scale Model... !

smile.gif

At your scale, 20k AU = 340km. According to GoogleEarth, Kendal Castle to Wembley Stadium 348km. Bingo! smile.gif
Go to the top of the page
 
+Quote Post
Stu
post Apr 29 2010, 02:22 PM
Post #19


The Poet Dude
****

Group: Moderator
Posts: 5548
Joined: 15-March 04
From: Kendal, Cumbria, UK
Member No.: 60



Brilliant! Thanks PFK, you just scribbled one item off my To Do list for me! laugh.gif



--------------------
Go to the top of the page
 
+Quote Post
Big_Gazza
post Apr 29 2010, 11:57 PM
Post #20


Junior Member
**

Group: Members
Posts: 66
Joined: 8-November 05
From: Australia
Member No.: 547



Not wanting to inject controversy into this thread laugh.gif but if Tyche does indeed exist, would the current IAU "rules" result in this object being considered a planet or a "dwarf"? Its a good assumption to believe the object will have reached hydrostatic equilibrium and be a spheroid, but has it cleared its neighbourhood of debris and minor objects?

Wouldn't it be ironic (hilarious) if Sols largest companion was classified by IAU as a dwarf planet due to a technicality?
Go to the top of the page
 
+Quote Post
brellis
post Apr 30 2010, 12:15 AM
Post #21


Member
***

Group: Members
Posts: 710
Joined: 9-February 07
Member No.: 1700



Wouldn't Jupiter have to be upgraded to "Failed Star"? rolleyes.gif
Go to the top of the page
 
+Quote Post
Hungry4info
post Apr 30 2010, 12:42 AM
Post #22


Senior Member
****

Group: Members
Posts: 1020
Joined: 26-July 08
Member No.: 4270



I interpret the rule to mean that the object has to gravitationally dominate its region of space. Thus Earth, Jupiter, and Neptune are still planets, as would be "Tyche."


--------------------
-- Hungry4info (Sirius_Alpha)
Go to the top of the page
 
+Quote Post
Vultur
post Apr 30 2010, 02:05 AM
Post #23


Member
***

Group: Members
Posts: 196
Joined: 9-September 08
Member No.: 4334



What is the total mass of the Oort Cloud? I'm pretty sure it is vastly less than 1 Jupiter mass (as supposedly Jupiter outweighs everything else in the System combined, except the Sun) in which case this object would (as I understand it) be considered dominant in its region, as it outweighed all the debris in its orbit (as, say, Ceres doesn't.)
Go to the top of the page
 
+Quote Post
nprev
post Apr 30 2010, 02:12 AM
Post #24


Senior Member
****

Group: Moderator
Posts: 7102
Joined: 8-December 05
From: Los Angeles
Member No.: 602



I wouldn't be surprised it's vastly less than an Earth mass...probably less than even that of the Moon. Lotta snowballs out there, not much rock.


--------------------
A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
Go to the top of the page
 
+Quote Post
Greg Hullender
post Apr 30 2010, 02:31 AM
Post #25


Senior Member
****

Group: Members
Posts: 1010
Joined: 29-November 05
From: Seattle, WA, USA
Member No.: 590



I see it estimated anywhere from 40 Earth masses to as little as 1.

Lots of Oort, not so much cloud. ;-)

--Greg
Go to the top of the page
 
+Quote Post
brellis
post Oct 2 2010, 02:38 AM
Post #26


Member
***

Group: Members
Posts: 710
Joined: 9-February 07
Member No.: 1700



It gets a little confusing to hear about the Voyagers approaching one type of solar system boundary, while the Oorties are so much further out there! huh.gif
Go to the top of the page
 
+Quote Post
dmuller
post Oct 2 2010, 07:37 AM
Post #27


Member
***

Group: Members
Posts: 332
Joined: 11-April 08
From: Sydney, Australia
Member No.: 4093



What's the Hillsphere of the Sun?


--------------------
Go to the top of the page
 
+Quote Post
centsworth_II
post Oct 2 2010, 08:00 AM
Post #28


Senior Member
****

Group: Members
Posts: 2061
Joined: 28-December 04
Member No.: 132



QUOTE (dmuller @ Oct 2 2010, 02:37 AM) *
What's the Hillsphere of the Sun?

From this quick Google grab:
"If it is agreed to assume a Hill sphere for the boundaries of the solar system [230,000au],
it is found that these boundaries extend to the nearest stars. However, stable motion of the
planets (with direct motion) probably is possible only within the solar gravitational sphere. [4500au]"
Attached Image
Go to the top of the page
 
+Quote Post
nprev
post Oct 2 2010, 08:42 AM
Post #29


Senior Member
****

Group: Moderator
Posts: 7102
Joined: 8-December 05
From: Los Angeles
Member No.: 602



I was going to ask why the radius of the Sun's Hill sphere would have to be "assumed", but then I found this calculator to approximate it. Since it involves the masses of two bodies, I guess that a sufficiently massive planet could be in solar orbit at a considerable distance (much greater than I'd thought possible).


--------------------
A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
Go to the top of the page
 
+Quote Post
centsworth_II
post Oct 2 2010, 08:57 AM
Post #30


Senior Member
****

Group: Members
Posts: 2061
Joined: 28-December 04
Member No.: 132



Looking back to the previous page (621) to the page I link (622), It looks like the two bodies used are the sun and the whole galaxy. The major assumptions are the mass of the galaxy and assuming that mass to be concentrated at the center of the galaxy. I wonder if more recent calculations deviate much from this one.
Go to the top of the page
 
+Quote Post

3 Pages V  < 1 2 3 >
Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 1st November 2014 - 02:32 AM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is a project of the Planetary Society and is funded by donations from visitors and members. Help keep this forum up and running by contributing here.