Fanography

A tool to visually study the geography of Fano 3-folds.

Fano threefolds with $\rho=1$

ID$-\mathrm{K}_X^3$$g$$\mathrm{h}^{1,2}$indexdescriptionblowupsrationalunirationalmoduli$\mathrm{Aut}^0$
1-122521

double cover of $\mathbb{P}^3$ with branch locus a divisor of degree 6

alternative
hypersurface of degree 6 in $\mathbb{P}(1,1,1,1,3)$
no?68$0$
1-243301
  1. hypersurface of degree 4 in $\mathbb{P}^4$
  2. double cover of 1-16 with branch locus a divisor of degree 8
nosome
  1. 45
  2. 44
$0$
1-364201

complete intersection of quadric and cubic in $\mathbb{P}^5$

noyes34$0$
1-485141

complete intersection of 3 quadrics in $\mathbb{P}^6$

noyes27$0$
1-5106101Gushel–Mukai 3-fold
  1. section of Plücker embedding of $\mathrm{Gr}(2,5)$ by codimension 2 subspace and a quadric
  2. double cover of 1-15 with branch locus an anticanonical divisor
generically non-rationalyes
  1. 22
  2. 19
$0$
1-612771

section of half-spinor embedding of a connected component of $\mathrm{OGr}_+(5,10)$ by codimension 7 subspace

yesyes18$0$
1-714851

section of Plücker embedding of $\mathrm{Gr}(2,6)$ by codimension 5 subspace

noyes15$0$
1-816931

section of Plücker embedding of $\mathrm{SGr}(3,6)$ by codimension 3 subspace

yesyes12$0$
1-9181021

section of the adjoint $\mathrm{G}_2$-Grassmannian $\mathrm{G}_2\mathrm{Gr}(2,7)$ by codimension 2 subspace

yesyes10$0$
1-10221201

zero locus of $(\bigwedge^2\mathcal{U}^\vee)^{\oplus 3}$ on $\mathrm{Gr}(3,7)$

yesyes6
$\mathrm{Aut}^0(X)$moduli
$\mathrm{PGL}_2$0
$\mathbb{G}_{\mathrm{a}}$0
$\mathbb{G}_{\mathrm{m}}$1
1-118212double Veronese cone

hypersurface of degree 6 in $\mathbb{P}(1,1,1,2,3)$

*no?34$0$
1-1216102quartic double solid

double cover of $\mathbb{P}^3$ with branch locus a smooth quartic surface

alternative
hypersurface of degree 4 in $\mathbb{P}(1,1,1,1,2)$
*noyes19$0$
1-132452

hypersurface of degree 3 in $\mathbb{P}^4$

*noyes10$0$
1-143222

complete intersection of 2 quadrics in $\mathbb{P}^5$

*yesyes3$0$
1-154002quintic del Pezzo threefold

section of Plücker embedding of $\mathrm{Gr}(2,5)$ by codimension 3 subspace

*yesyes0$\mathrm{PGL}_2$
1-165403

hypersurface of degree 2 in $\mathbb{P}^4$

*yesyes0$\mathrm{PSO}_5$
1-176404

projective space $\mathbb{P}^3$

*yesyes0$\mathrm{PGL}_4$

Fano threefolds with $\rho=2$

ID$-\mathrm{K}_X^3$$\mathrm{h}^{1,2}$indexdescriptionblowupsblowdownsrationalunirationalmoduli$\mathrm{Aut}^0$
2-14221

blowup of 1-11 in an elliptic curve which is the intersection of two divisors from half the anticanonical linear system

1-11no?36$0$
2-26201

double cover of 2-34 with branch locus a $(2,4)$-divisor

noyes33$0$
2-38111

blowup of 1-12 in an elliptic curve which is the intersection of two divisors from half the anticanonical linear system

1-12noyes23$0$
2-410101

blowup of 1-17 in the intersection of two cubics

alternative
$(1,3)$-divisor on $\mathbb{P}^1\times\mathbb{P}^3$
1-17yesyes21$0$
2-51261

blowup of 1-13 in a plane cubic

1-13noyes16$0$
2-61291Verra 3-fold
  1. $(2,2)$-divisor on $\mathbb{P}^2\times\mathbb{P}^2$
  2. double cover of 2-32 with branch locus an anticanonical divisor
noyes
  1. 19
  2. 18
$0$
2-71451

blowup of 1-16 in the intersection of two divisors from $|\mathcal{O}_Q(2)|$

1-16yesyes14$0$
2-81491
  1. double cover of 2-35 with branch locus an anticanonical divisor such that the intersection with the exceptional divisor is smooth
  2. double cover of 2-35 with branch locus an anticanonical divisor such that the intersection with the exceptional divisor is singular but reduced
noyes
  1. 18
  2. 17
$0$
2-91651

complete intersection of degree $(1,1)$ and $(2,1)$ in $\mathbb{P}^3\times\mathbb{P}^2$

alternative
blowup of 1-17 in a curve of degree 7 and genus 5, which is an intersection of 3 cubics
1-17yesyes13$0$
2-101631

blowup of 1-14 in an elliptic curve which is an intersection of 2 hyperplanes

1-14yesyes11$0$
2-111851

blowup of 1-13 in a line

1-13noyes12$0$
2-122031

intersection of 3 $(1,1)$-divisors in $\mathbb{P}^3\times\mathbb{P}^3$

alternative
blowup of 1-17 in a curve of degree 6 and genus 3 which is an intersection of 4 cubics
1-17yesyes9$0$
2-132021

blowup of 1-16 in a curve of degree 6 and genus 2

1-16yesyes8$0$
2-142011

blowup of 1-15 in an elliptic curve which is an intersection of 2 hyperplanes

1-15yesyes7$0$
2-152241
  1. blowup of 1-17 in the intersection of a quadric and a cubic where the quadric is smooth
  2. blowup of 1-17 in the intersection of a quadric and a cubic where the quadric is singular but reduced
1-17yesyes
  1. 9
  2. 8
$0$
2-162221

blowup of 1-14 in a conic

1-14yesyes7$0$
2-172411

blowup of 1-16 in an elliptic curve of degree 5

1-16, 1-17yesyes5$0$
2-182421

double cover of 2-34 with branch locus a divisor of degree $(2,2)$

*yesyes6$0$
2-192621

blowup of 1-14 in a line

1-14, 1-17yesyes5$0$
2-202601

blowup of 1-15 in a twisted cubic

1-15yesyes3
$\mathrm{Aut}^0(X)$moduli
$\mathbb{G}_{\mathrm{m}}$0
2-212801

blowup of 1-16 in a twisted quartic

1-16yesyes2
$\mathrm{Aut}^0(X)$moduli
$\mathrm{PGL}_2$0
$\mathbb{G}_{\mathrm{a}}$0
$\mathbb{G}_{\mathrm{m}}$1
2-223001

blowup of 1-15 in a conic

1-15, 1-17yesyes1
$\mathrm{Aut}^0(X)$moduli
$\mathbb{G}_{\mathrm{m}}$0
2-233011
  1. blowup of 1-16 in an intersection of $A\in|\mathcal{O}_Q(1)|$ and $B\in|\mathcal{O}_Q(2)|$ such that $A$ is smooth
  2. blowup of 1-16 in an intersection of $A\in|\mathcal{O}_Q(1)|$ and $B\in|\mathcal{O}_Q(2)|$ such that $A$ is singular
1-16yesyes
  1. 2
  2. 1
$0$
2-243001

divisor on $\mathbb{P}^2\times\mathbb{P}^2$ of bidegree $(1,2)$

*yesyes1
$\mathrm{Aut}^0(X)$moduli
$\mathbb{G}_{\mathrm{m}}^2$0
$\mathbb{G}_{\mathrm{m}}$0
2-253211

blowup of 1-17 in an elliptic curve which is an intersection of 2 quadrics

alternative
$(1,2)$-divisor on $\mathbb{P}^1\times\mathbb{P}^3$
*1-17yesyes1$0$
2-263401

blowup of 1-15 in a line

1-15, 1-16yesyes0
$\mathrm{Aut}^0(X)$moduli
$\mathrm{B}$0
$\mathbb{G}_{\mathrm{m}}$0
2-273801

blowup of 1-17 in a twisted cubic

*1-17yesyes0$\mathrm{PGL}_2$
2-284011

blowup of 1-17 in a plane cubic

1-17yesyes1$\mathbb{G}_{\mathrm{a}}^3\rtimes\mathbb{G}_{\mathrm{m}}$
2-294001

blowup of 1-16 in a conic

*1-16yesyes0$\mathbb{G}_{\mathrm{m}}\times\mathrm{PGL}_2$
2-304601

blowup of 1-17 in a conic

*1-17yesyes0$\mathrm{PSO}_{5;1}$
2-314601

blowup of 1-16 in a line

*1-16yesyes0$\mathrm{PSO}_{5;2}$
2-324802

divisor on $\mathbb{P}^2\times\mathbb{P}^2$ of bidegree $(1,1)$

alternative
$\mathbb{P}(\mathrm{T}_{\mathbb{P}^2})$
the complete flag variety for $\mathbb{P}^2$
*yesyes0$\mathrm{PGL}_3$
2-335401

blowup of 1-17 in a line

*1-17yesyes0$\mathrm{PGL}_{4;2}$
2-345401

$\mathbb{P}^1\times\mathbb{P}^2$

*yesyes0$\mathrm{PGL}_2\times\mathrm{PGL}_3$
2-355602

$\mathrm{Bl}_p\mathbb{P}^3$

alternative
$\mathbb{P}(\mathcal{O}_{\mathbb{P}^2}\oplus\mathcal{O}_{\mathbb{P}^2}(1))$
*yesyes0$\mathrm{PGL}_{4;1}$
2-366201

$\mathbb{P}(\mathcal{O}_{\mathbb{P}^2}\oplus\mathcal{O}_{\mathbb{P}^2}(2))$

*yesyes0$\mathrm{Aut}(\mathbb{P}(1,1,1,2))$

Fano threefolds with $\rho=3$

ID$-\mathrm{K}_X^3$$\mathrm{h}^{1,2}$indexdescriptionblowupsblowdownsrationalunirationalmoduli$\mathrm{Aut}^0$
3-11281

double cover of 3-27 with branch locus a divisor of degree $(2,2,2)$

noyes17$0$
3-21431

divisor from $|\mathcal{L}^{\otimes 2}\otimes\mathcal{O}(2,3)|$ on the $\mathbb{P}^2$-bundle $\mathbb{P}(\mathcal{O}\oplus\mathcal{O}(-1,-1)^{\oplus 2})$ over $\mathbb{P}^1\times\mathbb{P}^1$ such that $X\cap Y$ is irreducible, and $\mathcal{L}$ is the tautological bundle, and $Y\in|\mathcal{L}|$

yesyes11$0$
3-31831

divisor on $\mathbb{P}^1\times\mathbb{P}^1\times\mathbb{P}^2$ of degree $(1,1,2)$

2-34yesyes9$0$
3-41821

blowup of 2-18 in a smooth fiber of the composition of the projection to $\mathbb{P}^1\times\mathbb{P}^2$ with the projection to $\mathbb{P}^2$ of the double cover with the projection

2-18yesyes8$0$
3-52001

blowup of 2-34 in a curve $C$ of degree $(5,2)$ such that $C\hookrightarrow\mathbb{P}^1\times\mathbb{P}^2\to\mathbb{P}^2$ is an embedding

2-34yesyes5
$\mathrm{Aut}^0(X)$moduli
$\mathbb{G}_{\mathrm{m}}$0
3-62211

blowup of 1-17 in the disjoint union of a line and an elliptic curve of degree 4

alternative
complete intersection of degree $(1,0,2)$ and $(0,1,1)$ in $\mathbb{P}^1\times\mathbb{P}^1\times\mathbb{P}^3$
2-25, 2-33yesyes5$0$
3-72411

blowup of 2-32 in an elliptic curve which is the intersection of two divisors from $|-\frac{1}{2}\mathrm{K}_W|$

2-32, 2-34yesyes4$0$
3-82401

divisor from the linear system $|(\alpha\circ\pi_1)^*(\mathcal{O}_{\mathbb{P}^2}(1)\otimes\pi_2^*(\mathcal{O}_{\mathbb{P}^2}(2))|$ where $\pi_i\colon\mathrm{Bl}_1\mathbb{P}^2\times\mathbb{P}^2\to\mathrm{Bl}_1\mathbb{P}^2,\mathbb{P}^2$ are the projections, and $\alpha\colon\mathrm{Bl}_1\mathbb{P}^2\to\mathbb{P}^2$ is the blowup

2-24, 2-34yesyes3
$\mathrm{Aut}^0(X)$moduli
$\mathbb{G}_{\mathrm{m}}$0
3-92631

blowup of the cone over the Veronese of $\mathbb{P}^2$ in $\mathbb{P}^5$ with center the disjoint union of the vertex and a quartic curve on $\mathbb{P}^2$

2-36yesyes6$\mathbb{G}_{\mathrm{m}}$
3-102601

blowup of 1-16 in the disjoint union of 2 conics

alternative
complete intersection of degree $(1,0,1)$, $(0,1,1)$ and $(0,0,2)$ in $\mathbb{P}^1\times\mathbb{P}^1\times\mathbb{P}^4$
2-29yesyes2
$\mathrm{Aut}^0(X)$moduli
$\mathbb{G}_{\mathrm{m}}^2$0
$\mathbb{G}_{\mathrm{m}}$1
3-112811

blowup of 2-35 in an elliptic curve which is the intersection of two divisors from $|-\frac{1}{2}\mathrm{K}_{V_7}|$

2-25, 2-34, 2-35yesyes2$0$
3-122801

blowup of 1-17 in the disjoint union of a line and a twisted cubic

2-27, 2-33, 2-34yesyes1
$\mathrm{Aut}^0(X)$moduli
$\mathbb{G}_{\mathrm{m}}$0
3-133001

blowup of 2-32 in a curve $C$ of bidegree $(2,2)$ such that the composition $C\hookrightarrow W\hookrightarrow\mathbb{P}^2\times\mathbb{P}^2\overset{p_i}{\to}\mathbb{P}^2$ is an embedding for $i=1,2$

2-32yesyes1
$\mathrm{Aut}^0(X)$moduli
$\mathrm{PGL}_2$0
$\mathbb{G}_{\mathrm{a}}$0
$\mathbb{G}_{\mathrm{m}}$1
3-143211

blowup of 1-17 in the disjoint union of a plane cubic curve and a point outside the plane

2-35, 2-36yesyes1$\mathbb{G}_{\mathrm{m}}$
3-153201

blowup of 1-16 in the disjoint union of a line and a conic

2-29, 2-31, 2-34yesyes0$\mathbb{G}_{\mathrm{m}}$
3-163401

blowup of 2-35 in the proper transform of a twisted cubic containing the center of the blowup

2-27, 2-32, 2-35yesyes0$\mathrm{B}$
3-173601

divisor on $\mathbb{P}^1\times\mathbb{P}^1\times\mathbb{P}^2$ of degree $(1,1,1)$

*2-34yesyes0$\mathrm{PGL}_2$
3-183601

blowup of 1-17 in the disjoint union of a line and a conic

*2-29, 2-30, 2-33yesyes0$\mathrm{B}\times\mathbb{G}_{\mathrm{m}}$
3-193801

blowup of 1-16 in two non-collinear points

*2-35yesyes0$\mathbb{G}_{\mathrm{m}}\times\mathrm{PGL}_2$
3-203801

blowup of 1-16 in the disjoint union of two lines

2-31, 2-32yesyes0$\mathbb{G}_{\mathrm{m}}\times\mathrm{PGL}_2$
3-213801

blowup of 2-34 in a curve of degree $(2,1)$

*2-34yesyes0$\mathbb{G}_{\mathrm{a}}^2\rtimes\mathbb{G}_{\mathrm{m}}^2$
3-224001

blowup of 2-34 in a conic on $\{x\}\times\mathbb{P}^2$, $x\in\mathbb{P}^1$

2-34, 2-36yesyes0$\mathrm{B}\times\mathrm{PGL}_2$
3-234201

blowup of 2-35 in the proper transform of a conic containing the center of the blowup

2-30, 2-31, 2-35yesyes0$\mathbb{G}_{\mathrm{a}}^3\rtimes(\mathrm{B}\times\mathbb{G}_{\mathrm{m}})$
3-244201

the fiber product of 2-32 with $\mathrm{Bl}_p\mathbb{P}^2$ over $\mathbb{P}^2$

alternative
complete intersection of degree $(1,1,0)$ and $(0,1,1)$ in $\mathbb{P}^1\times\mathbb{P}^2\times\mathbb{P}^2$
*2-32, 2-34yesyes0$\mathrm{PGL}_{3;1}$
3-254401

blowup of 1-17 in the disjoint union of two lines

alternative
$\mathbb{P}(\mathcal{O}(1,0)\oplus\mathcal{O}(0,1))$ over $\mathbb{P}^1\times\mathbb{P}^1$
*2-33yesyes0$\mathrm{PGL}_{(2,2)}$
3-264601

blowup of 1-17 in the disjoint union of a point and a line

alternative
blowup of line on a plane which is section of 2-34 mapping to $\mathbb{P}^2$
*2-34, 2-35yesyes0$\mathbb{G}_{\mathrm{a}}^3\rtimes(\mathrm{GL}_2\times\mathbb{G}_{\mathrm{m}})$
3-274802

$\mathbb{P}^1\times\mathbb{P}^1\times\mathbb{P}^1$

*yesyes0$\mathrm{PGL}_2^3$
3-284801

$\mathbb{P}^1\times\mathrm{Bl}_p\mathbb{P}^2$

*2-34yesyes0$\mathrm{PGL}_2\times\mathrm{PGL}_{3;1}$
3-295001

blowup of 2-35 in a line on the exceptional divisor

2-35yesyes0$\mathrm{PGL}_{4;3,1}$
3-305001

blowup of 2-35 in the proper transform of a line containing the center of the blowup

alternative
$\mathbb{P}_{\mathbb{F}_1}(\mathcal{O}\oplus\mathcal{O}(\ell))$ where $\ell^2=1$
*2-33, 2-35yesyes0$\mathrm{PGL}_{4;2,1}$
3-315201

blowup of the cone over a smooth quadric in $\mathbb{P}^3$ in the vertex

alternative
$\mathbb{P}(\mathcal{O}\oplus\mathcal{O}(1,1))$ over $\mathbb{P}^1\times\mathbb{P}^1$
*yesyes0$\mathrm{PSO}_{6;1}$

Fano threefolds with $\rho=4$

ID$-\mathrm{K}_X^3$$\mathrm{h}^{1,2}$descriptionblowupsblowdownsrationalunirationalmoduli$\mathrm{Aut}^0$
4-1241

divisor on $\mathbb{P}^1\times\mathbb{P}^1\times\mathbb{P}^1\times\mathbb{P}^1$ of degree $(1,1,1,1)$

3-27yesyes3$0$
4-2281

blowup of the cone over a smooth quadric in $\mathbb{P}^3$ in the disjoint union of the vertex and an elliptic curve on the quadric

3-31yesyes2$\mathbb{G}_{\mathrm{m}}$
4-3300

blowup of 3-27 in a curve of degree $(1,1,2)$

3-17, 3-27, 3-28yesyes0$\mathbb{G}_{\mathrm{m}}$
4-4320

blowup of 3-19 in the proper transform of a conic through the points

*3-18, 3-19, 3-30yesyes0$\mathbb{G}_{\mathrm{m}}^2$
4-5320

blowup of 2-34 in the disjoint union of a curve of degree $(2,1)$ and a curve of degree $(1,0)$

3-21, 3-28, 3-31yesyes0$\mathbb{G}_{\mathrm{m}}^2$
4-6340

blowup of 1-17 in the disjoint union of 3 lines

alternative
blowup of 3-27 in the tridiagonal
3-25, 3-27yesyes0$\mathrm{PGL}_2$
4-7360

blowup of 2-32 in the disjoint union of a curve of degree $(0,1)$ and a curve of degree $(1,0)$

3-24, 3-28yesyes0$\mathrm{GL}_2$
4-8380

blowup of 3-27 in a curve of degree $(0,1,1)$

3-27, 3-31yesyes0$\mathrm{B}\times\mathrm{PGL}_2$
4-9400

blowup of 3-25 in an exceptional curve of the blowup

*3-25, 3-26, 3-28, 3-30yesyes0$\mathrm{PGL}_{(2,2);1}$
4-10420

$\mathbb{P}^1\times\mathrm{Bl}_2\mathbb{P}^2$

*3-27, 3-28yesyes0$\mathrm{PGL}_2\times\mathrm{B}^2$
4-11440

blowup of 3-28 in $\{x\}\times E$, $x\in\mathbb{P}^1$ and $E$ the $(-1)$-curve

*3-28, 3-31yesyes0$\mathrm{B}\times\mathrm{PGL}_{3;1}$
4-12460

blowup of 2-33 in the disjoint union of two exceptional lines of the blowup

*3-30yesyes0$\mathbb{G}_{\mathrm{a}}^4\rtimes(\mathrm{GL}_2\times\mathbb{G}_{\mathrm{m}})$
4-13260

blowup of 3-27 in a curve of degree $(1,1,3)$

3-27, 3-31yesyes1
$\mathrm{Aut}^0(X)$moduli
$\mathbb{G}_{\mathrm{m}}$0

Fano threefolds with $\rho=5$

ID$-\mathrm{K}_X^3$$\mathrm{h}^{1,2}$descriptionblowupsblowdownsrationalunirationalmoduli$\mathrm{Aut}^0$
5-1280

blowup of 2-29 in the disjoint union of three exceptional lines of the blowup

4-4, 4-12yesyes0$\mathbb{G}_{\mathrm{m}}$
5-2360

blowup of 3-25 in the disjoint union of two exceptional lines on the same irreducible component

4-9, 4-11, 4-12yesyes0$\mathbb{G}_{\mathrm{m}}\times\mathrm{GL}_2$
5-3360

$\mathbb{P}^1\times\mathrm{Bl}_3\mathbb{P}^2$

*4-10yesyes0$\mathrm{PGL}_2\times\mathbb{G}_{\mathrm{m}}^2$

Fano threefolds with $\rho=6$

ID$-\mathrm{K}_X^3$$\mathrm{h}^{1,2}$descriptionblowupsblowdownsrationalunirationalmoduli$\mathrm{Aut}^0$
6-1300

$\mathbb{P}^1\times\mathrm{Bl}_4\mathbb{P}^2$

*5-3yesyes0$\mathrm{PGL}_2$

Fano threefolds with $\rho=7$

ID$-\mathrm{K}_X^3$$\mathrm{h}^{1,2}$descriptionblowupsblowdownsrationalunirationalmoduli$\mathrm{Aut}^0$
7-1240

$\mathbb{P}^1\times\mathrm{Bl}_5\mathbb{P}^2$

*6-1yesyes2$\mathrm{PGL}_2$

Fano threefolds with $\rho=8$

ID$-\mathrm{K}_X^3$$\mathrm{h}^{1,2}$descriptionblowupsblowdownsrationalunirationalmoduli$\mathrm{Aut}^0$
8-1180

$\mathbb{P}^1\times\mathrm{Bl}_6\mathbb{P}^2$

*7-1yesyes4$\mathrm{PGL}_2$

Fano threefolds with $\rho=9$

ID$-\mathrm{K}_X^3$$\mathrm{h}^{1,2}$descriptionblowupsblowdownsrationalunirationalmoduli$\mathrm{Aut}^0$
9-1120

$\mathbb{P}^1\times\mathrm{Bl}_7\mathbb{P}^2$

*8-1yesyes6$\mathrm{PGL}_2$

Fano threefolds with $\rho=10$

ID$-\mathrm{K}_X^3$$\mathrm{h}^{1,2}$descriptionblowdownsrationalunirationalmoduli$\mathrm{Aut}^0$
10-160

$\mathbb{P}^1\times\mathrm{Bl}_8\mathbb{P}^2$

9-1yesyes8$\mathrm{PGL}_2$