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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').
Advanced Search

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"

20545 results found.

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

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