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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

20542 results found.

  1. GRB 241209A: COLIBRÍ Optical Upper Limit
  2. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  3. GRB 241209A: GRANDMA/TAROT upper limit
  4. GRB 241209A: REM optical/NIR observations
  5. GRB 241209D: Enhanced Swift-XRT position
  6. GRB 241209D: Swift detection of a burst
  7. GRB 241209A: VLT/X-shooter spectroscopy
  8. GRB 241209A: Enhanced Swift-XRT position
  9. GRB 241209A: VLT optical observations
  10. GRB 241209A: GOTO optical upper limits
  11. GRB 241209B: SVOM/ECLAIRs and GRM detection of a long burst
  12. EP241208a: EP detection of a fast X-ray transient
  13. GRB 241209A: Swift detection of a short burst
  14. GRB 241207B: Swift/BAT-GUANO localization skymap of a short burst
  15. GRB 241206A: DDOTI Upper Limit on the Afterglow
  16. EP241206a: BOOTES Global Network optical limits
  17. EP241206a: EP detection of a fast X-ray transient
  18. GRB 241206A: Swift/BAT-GUANO localization skymap of a burst
  19. EP241201a: 1.6m Mephisto Optical Upper Limits
  20. GRB 241204A: COLIBRÍ Optical Upper Limit
  21. EP241202b: KAIT optical upper limit
  22. GRB 241204A: DDOTI Upper Limits on the Afterglow
  23. GRB 241204A: Fermi-LAT detection
  24. IceCube-241127A: No transient candidates from the Zwicky Transient Facility
  25. EP241202b: Kinder optical counterpart candidate
  26. Fermi-GBM Sub-Threshold Detection of GRB 241128A
  27. EP241202b: EP detection of a fast X-ray transient
  28. EP241201a: NOT optical observations
  29. GRB 241128A: Swift/UVOT Upper Limits
  30. IceCube-241127A: Upper limits from a search for additional neutrino events in IceCube
  31. GRB 241129A: Swift/BAT-GUANO localization skymap of a burst
  32. EP241201a: Kinder optical counterpart candidate
  33. LIGO/Virgo/KAGRA S241102br: GRAWITA wide-field optical observations
  34. EP241201a: EP detection of a fast X-ray transient
  35. GRB 241127B: detection of a long GRB by SVOM/ECLAIRs
  36. EP241126a: 1.6m Mephisto Optical Upper Limits
  37. LIGO/Virgo/KAGRA S241201ac: Identification of a GW compact binary merger candidate
  38. LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
  39. GRB 241128A: AbAO optical upper limit
  40. LIGO/Virgo/KAGRA S241130be: Identification of a GW compact binary merger candidate
  41. LIGO/Virgo/KAGRA S241130n: Identification of a GW compact binary merger candidate
  42. GRB 241127A: PRIME near-infrared detection
  43. GRB 241128A: Mondy optical observations
  44. GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
  45. Swift-XRT observations of IceCube -241127A
  46. LIGO/Virgo/KAGRA S241129aa: Identification of a GW compact binary merger candidate
  47. GRB 241128A: Enhanced Swift-XRT position
  48. GRB 241128A: NOT optical observations
  49. GRB 241128A: LCO optical detection
  50. GRB 241128A: Swift-XRT afterglow detection
  51. GRB 241128A: Swift detection of a burst
  52. GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
  53. GRB 241127A: Swift/UVOT Detection
  54. GRB 241127A: Enhanced Swift-XRT position
  55. GRB 241127A: LCOGT (40-cm) optical counterpart detection
  56. EP241126a: WFST Observations
  57. GRB 241127A: Swift detection of a burst with an optical counterpart
  58. LIGO/Virgo/KAGRA S241125n: Preliminary flux estimate and spectral analysis of the Swift/BAT-GUANO candidate counterpart
  59. LIGO/Virgo/KAGRA S241125n: Swift-UVOT Upper Limits
  60. EP241126a: Optical Upper limits with Kinder observations
  61. IPN triangulation of GRB 241114B
  62. EP trigger ID 01709122294: 1.6m Mephisto multi-band optical observations
  63. EP241126a: TRT optical counterpart detection
  64. LIGO/Virgo/KAGRA S241127aj: Identification of a GW compact binary merger candidate
  65. EP241126a: EP detection of a fast X-ray transient
  66. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on Optical Counterparts to Two of the Swift/XRT Sources
  67. LIGO/Virgo/KAGRA S241125n: SAGUARO follow-up observations with the MMT
  68. LIGO/Virgo/KAGRA S241125n: DDOTI Optical Upper Limits
  69. LIGO/Virgo/KAGRA S241125n: Gaoyazi/GOT optical observations
  70. LIGO/VIRGO/KAGRA S241125n: GROWTH-India telescope optical observations
  71. LIGO/Virgo S241125n: Swift XRT observations, 5 X-ray sources
  72. LIGO/Virgo/KAGRA S241125n: HCT upper limit
  73. GRB 241026A: radio detection with the VLA
  74. EP241125a: Optical upper limit with Kinder observations
  75. EP241125a: EP detection of an X-ray transient
  76. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on a Optical Counterpart at the BAT Position
  77. LIGO/Virgo/KAGRA S241125n: Kinder optical upper limit in the BAT error region
  78. LIGO/Virgo/KAGRA S241109bn: Upper limits from a two-week IceCube neutrino search
  79. LIGO/Virgo/KAGRA S241125n: Swift/BAT-GUANO candidate counterpart
  80. LIGO/Virgo/KAGRA S241125n: Identification of a GW compact binary merger candidate
  81. LIGO/Virgo/KAGRA S241122a: Updated Sky localization and Source Classification
  82. LIGO/Virgo/KAGRA S241122a: Identification of a GW compact binary merger candidate
  83. IPN triangulation of GRB 241117A
  84. GRB 241026A: VIRT Optical Upper Limit
  85. GRB 241025A: VIRT Optical Upper Limit
  86. GRB241120A: OHP/T193 optical observations
  87. EP241021a and EP241026b: Keck/LRIS spectroscopic observations
  88. GRB 241120A: Mondy and AbAO optical observations
  89. EP241119a: Optical upper limits with Kinder observations
  90. EP trigger ID 01709122294: the X-ray transient is likely a stellar flare event
  91. EP241119a: GIT optical upper limits
  92. EP241119a : J-band observations with WINTER
  93. EP241119a: EP detection of a fast X-ray transient
  94. GRB241120A: a long GRB detected by INTEGRAL
  95. GRB 241112B: Mephisto further optical observations
  96. GRB 241030A: J-band observations
  97. GRB 241115a: PRIME near-infrared upper limits
  98. GRB 241117A: Swift/BAT-GUANO localization skymap of a burst
  99. GRB 241117A: SVOM/GRM observation of a short burst with extended emission
  100. IceCube-Cascade 241116A: Upper limits from a search for additional neutrino events in IceCube

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