lithium - 2025 ACF Regionals

Question

The B2FH paper supported Fred Hoyle’s hypothesis that all elements heavier than this element were not formed through BBN. For 10 points each:

[10h] Name this element that is proposed to sink beneath a star’s atmosphere over time, thus increasing the rate of turbulent mixing. This element is the heaviest whose distribution is depicted on the Schramm plot.

ANSWER: lithium [or Li; accept lithium-7 or Li-7]

[10e] The brown type of these stars can be identified via the relative abundance of lithium. The white type of these low-mass stars forms after sun-like stars run out of fuel.

ANSWER: dwarf stars [accept brown dwarfs or white dwarfs]

[10m] A major source of lithium is the “classical” type of these phenomena, which are about 1,000 times brighter than their “recurrent” type. The “dwarf” type of these phenomena necessarily occurs [emphasize] below the Chandrasekhar limit.

ANSWER: novae [or novas; accept classical novae or recurrent novae or dwarf novae; reject “supernova” or “kilonova”]

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Summary


California	2025-02-01	Y	3	13.33	100%	0%	33%
Florida	2025-02-01	Y	3	3.33	33%	0%	0%
Great Lakes	2025-02-01	Y	6	15.00	100%	33%	17%
Lower Mid-Atlantic	2025-02-01	Y	6	15.00	100%	33%	17%
Midwest	2025-02-01	Y	6	15.00	100%	33%	17%
North	2025-02-01	Y	3	16.67	100%	67%	0%
Northeast	2025-02-01	Y	5	12.00	100%	20%	0%
Overflow	2025-02-01	Y	5	18.00	100%	60%	20%
South Central	2025-02-01	Y	2	20.00	100%	100%	0%
Southeast	2025-02-01	Y	3	10.00	100%	0%	0%
UK	2025-02-01	Y	10	12.00	100%	10%	10%
Upper Mid-Atlantic	2025-02-01	Y	7	14.29	100%	29%	14%
Upstate NY	2025-02-01	Y	3	13.33	100%	33%	0%

Data


Claremont B	UCLA	0	10	0	10
UC Berkeley A	UCSD	0	10	0	10
WashU A	Chicago A	0	10	0	10
Southampton A	Cambridge D	0	10	0	10
Manchester	Cambridge E	10	10	10	30
Durham	Cambridge A	0	10	0	10
Oxford A	Imperial B	0	10	0	10
LSE	Bristol	0	10	0	10
Cambridge C	NYU C	0	10	0	10
Claremont A	UC Berkeley B	10	10	0	20
UCF C	Florida A	0	0	0	0
UCF B	Florida B	0	0	0	0
Florida State A	Valencia A	0	10	0	10
Michigan D	Carnegie Mellon A	0	10	10	20
Carnegie Mellon B	Case Western A	0	10	0	10
Ohio State A	Kenyon	0	10	0	10
Ohio State B	Michigan B	10	10	0	20
UNC B	Duke	10	10	10	30
UNC D	South Carolina	0	10	10	20
Brandeis B	Dartmouth A	0	10	0	10
Harvard A	Brown A	0	10	0	10
MIT A	BU	0	10	10	20
Harvard B	Tufts A	0	10	0	10
Brandeis A	UMass Boston	0	10	0	10
Georgetown A	Georgetown B	0	10	0	10
Iowa	Northwestern A	0	10	10	20
Northwestern B	Notre Dame A	0	10	0	10
Notre Dame B	Notre Dame C	0	10	10	20
Purdue	Stanford B	10	10	10	30
ASU	TAMU	0	10	10	20
Texas B	Texas A	0	10	10	20
Georgia Tech A	Georgia Tech B	0	10	0	10
Georgia Tech D	Georgia Tech C	0	10	0	10
Tennessee A	Vanderbilt A	0	10	0	10
Oxford B	Warwick A	0	10	0	10
Warwick B	Oxford C	0	10	0	10
George Washington A	George Washington B	0	10	0	10
Columbia B	Johns Hopkins A	0	10	10	20
Penn A	Vassar A	0	10	0	10
NYU A	Yale A	0	10	0	10
Binghamton A	RIT A	0	10	0	10
Cornell C	ESF A	0	10	0	10
Michigan A	Case Western B	0	10	10	20
Michigan State	Michigan C	0	10	0	10
William & Mary	Liberty A	0	10	0	10
Virginia Tech A	Liberty C	0	10	0	10
Virginia A	Liberty B	0	10	0	10
Wake Forest	UNC C	0	10	0	10
Chicago D	Chicago C	0	10	0	10
Illinois A	Chicago B	0	10	10	20
WashU B	Indiana B	10	10	10	30
Illinois C	Missoui S&T	0	10	0	10
Missouri	Illinois B	0	10	0	10
Carleton	Winona State	0	10	0	10
Minnesota B	Wisconsin A	0	10	10	20
Iowa State	Wisconsin B	0	10	10	20
Cambridge B	Sheffield	0	10	0	10
Southampton B	Imperial A	0	10	0	10
Cornell B	Maryland A	0	10	10	20
Columbia C	Maryland B	10	10	0	20
Rutgers A	John Jay College	0	10	0	10
Cornell D	RIT B	0	10	10	20