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Twilight Low-SE NEO Mini-Survey

Baseline:

  • No twilight NEO mini-survey

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Twilight Low-SE NEO Mini-Survey

v1.7:

  • 45° ≤ SE ≤ 60°
  • Morning & evening twilight
  • Typically 440 1-sec visits per night
  • Visits acquired in triplets (r, i, z) separated by ~3 minutes
  • Observing cadence options: every night, every other night, every third night, every fourth night, on 4 nights/off 4 nights, on 3/off 4, on 2/off 4
  • Uses 100% of twilight time

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Twilight Low-SE NEO Mini-Survey

v1.7:

  • 45° ≤ SE ≤ 60°
  • Morning & evening twilight
  • Typically 440 1-sec visits per night
  • Visits acquired in triplets (r, i, z) separated by ~3 minutes
  • Observing cadence options: every night, every other night, every third night, every fourth night, on 4 nights/off 4 nights, on 3/off 4, on 2/off 4
  • Uses 100% of twilight time
  • Analysis:
    • Hurt both WFD observing & overall SSO completeness
    • Would find IEOs (Atiras & Vatiras) – only way to view them!

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Twilight Low-SE NEO Mini-Survey

v1.7:

  • 45° ≤ SE ≤ 60°
  • Morning & evening twilight
  • Typically 440 1-sec visits per night
  • Visits acquired in triplets (r, i, z) separated by ~3 minutes
  • Observing cadence options: every night, every other night, every third night, every fourth night, on 4 nights/off 4 nights, on 3/off 4, on 2/off 4
  • Uses 100% of twilight time
  • Analysis:
    • Hurt both WFD observing & overall SSO completeness
    • Would find IEOs (Atiras & Vatiras) – only way to view them!
  • Proposed compromise: 4 nights on / 4 nights off at 50% of twilight time

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Twilight Low-SE NEO Mini-Survey

v2.0 (similar to v1.7 with 50% of twilight time):

  • 45° ≤ SE ≤ 60°
  • Morning & evening twilight
  • Typically 440 1-sec visits per night
  • Visits acquired in triplets (r, i, z) separated by ~3 minutes
  • Observing cadence options: every night, every other night, every third night, every fourth night, on 4 nights/off 4 nights, on 3/off 4, on 2/off 4

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Twilight Low-SE NEO Mini-Survey

v2.0 (similar to v1.7 with 50% of twilight time):

  • twilight_neo_nightpatternXXv2.0_10yrs Key:
    • nightpattern1: every night
    • nightpattern2: every other night (on 1 night / off 1 night)
    • nightpattern3: every third night (on 1 night / off 2 nights)
    • nightpattern4: every fourth night (on 1 night / off 3 nights)
    • nightpattern5: on 4 nights / off 4 nights
    • nightpattern6: on 3 nights / off 4 nights
    • nightpattern7: on 2 nights / off 4 nights

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SSO Completeness

Order of (slight) preference:

  • nightpattern5: on 4 / off 4
  • nightpattern7: on 2 / off 4
  • nightpattern4: on 1 / off 3
  • nightpattern6: on 3 / off 4
  • nightpattern3: on 1 / off 2
  • nightpattern2: on 1 / off 1
  • nightpattern1: every night

Drops: 2 - 4.5% (everything faint)

Increases: 3.5 - 5.5% (bright NEOs/PHAs)

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Faint NEO Completeness

Order of (slight) preference:

  • nightpattern4: on 1 / off 3
  • nightpattern5: on 4 / off 4
  • nightpattern3: on 1 / off 2
  • nightpattern7: on 2 / off 4
  • nightpattern2: on 1 / off 1
  • nightpattern6: on 3 / off 4
  • nightpattern1: every night

Drops: 1 - 9%

Increases: 2%

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Fraction 3 of g and (r or i) and (z or y)

Order of (slight) preference:

  • nightpattern4: on 1 / off 3
  • nightpattern3: on 1 / off 2
  • nightpattern7: on 2 / off 4
  • nightpattern5: on 4 / off 4
  • nightpattern6: on 3 / off 4
  • nightpattern2: on 1 / off 1
  • nightpattern1: every night

Drops: 1.5 - 7% (faint NEOs/PHAs)

Increases: 0.5 - 1% (bright NEOs/PHAs)

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Fraction 4 of grizy

Order of (slight) preference:

  • nightpattern4: on 1 / off 3
  • nightpattern7: on 2 / off 4
  • nightpattern3: on 1 / off 2
  • nightpattern6: on 3 / off 4
  • nightpattern5: on 4 / off 4
  • nightpattern2: on 1 / off 1
  • nightpattern1: every night

Drops: 1.5 - 7% (faint PHAs)

Increases: 0.5 - 1% (bright NEOs/PHAs)

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Fraction with grizy

Order of (slight) preference:

  • nightpattern4: on 1 / off 3
  • nightpattern6: on 3 / off 4
  • nightpattern7: on 2 / off 4
  • nightpattern5: on 4 / off 4
  • nightpattern3: on 1 / off 2
  • nightpattern2: on 1 / off 1
  • nightpattern1: every night

Drops: 3 - 13%

Increases: 0.5 - 2% (faint Trojans / bright TNOs)

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Fraction with ugrizy

Order of (slight) preference:

  • nightpattern6: on 3 / off 4
  • nightpattern3: on 1 / off 2
  • nightpattern5: on 4 / off 4
  • nightpattern4: on 1 / off 3
  • nightpattern2: on 1 / off 1
  • nightpattern7: on 2 / off 4
  • nightpattern1: every night

Drops: 8 - 23% (faint MBAs/bright Trojans)

Increases: 3 - 30% (faint / bright Trojans)

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Fraction LC inversion

Order of (slight) preference:

  • nightpattern4: on 1 / off 3
  • nightpattern2: on 1 / off 1
  • nightpattern6: on 3 / off 4
  • nightpattern3: on 1 / off 2
  • nightpattern7: on 2 / off 4
  • nightpattern5: on 4 / off 4
  • nightpattern1: every night

Drops: 10 - 32% (faint Trojans)

Increases: 30 - 50+% (bright NEOs/PHAs)

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v2.0 versus v1.7

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SSO Completeness (v2.0 - left; v1.7 - right)

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Fraction 3 of g and (r or i) and (z or y) (v2.0 - left; v1.7 - right)

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Fraction 4 of grizy (v2.0 - left; v1.7 - right)

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Fraction with grizy (v2.0 - left; v1.7 - right)

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Fraction with ugrizy (v2.0 - left; v1.7 - right)

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Fraction LC inversion (v2.0 - left; v1.7 - right)