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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

8474 results found.

  1. LIGO/Virgo/KAGRA S241125n: Kinder optical upper limit in the BAT error region
  2. LIGO/Virgo/KAGRA S241125n: Updated Sky localization
  3. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  4. LIGO/Virgo/KAGRA S241109bn: Upper limits from a two-week IceCube neutrino search
  5. LIGO/Virgo/KAGRA S241125n: Updated Sky localization and Coincidence with External Event
  6. LIGO/Virgo/KAGRA S241125n: Swift/BAT-GUANO candidate counterpart
  7. LIGO/Virgo/KAGRA S241125n: Identification of a GW compact binary merger candidate
  8. LIGO/Virgo/KAGRA S241122a: Updated Sky localization and Source Classification
  9. LIGO/Virgo/KAGRA S241122a: Identification of a GW compact binary merger candidate
  10. GRB241120A: OHP/T193 optical observations
  11. GRB 241120A: Mondy and AbAO optical observations
  12. GRB 241112B: Mephisto further optical observations
  13. LIGO/Virgo/KAGRA S241116cq: Upper limits from Swift/BAT-GUANO
  14. LIGO/Virgo/KAGRA S241114y: Updated Sky localization
  15. Updates to IceCube realtime alert system for muon tracks
  16. IceCube-Cascade 241116A: Upper limits from a search for additional neutrino events in IceCube
  17. LIGO/Virgo/KAGRA S241116cq: Updated Sky localization
  18. LIGO/Virgo/KAGRA S241116cq: Identification of a GW compact binary merger candidate
  19. GRB 241113B: Mephisto upper limits
  20. LIGO/Virgo/KAGRA S241114bi: Updated Sky localization and EM Bright Classification
  21. LIGO/Virgo/KAGRA S241113p: Updated Sky localization
  22. EP241113a: No Detection in Fermi-GBM Observations
  23. GRB 241115A: Swift detection of a burst
  24. EP 241113a: LBT possible optical counterpart
  25. GRB 241113B: KAIT Optical Afterglow Candidate
  26. LIGO/Virgo/KAGRA S241114bi: Upper limits from Fermi-GBM Observations
  27. LIGO/Virgo/KAGRA S241114bi: Coverage and upper limits from MAXI/GSC observations
  28. LIGO/Virgo/KAGRA S241114bi: Identification of a GW compact binary merger candidate
  29. IceCube-241113A: Upper limits from a search for additional neutrino events in IceCube
  30. LIGO/Virgo/KAGRA S241114y: Identification of a GW compact binary merger candidate
  31. Konus-Wind detection of GRB 241107A (short/hard)
  32. LIGO/Virgo/KAGRA S241113p: Identification of a GW compact binary merger candidate
  33. GRB 241113B: Swift ToO observations
  34. IceCube-241113A - IceCube observation of a high-energy neutrino candidate track-like event
  35. LIGO/Virgo/KAGRA S241111bn: Updated Sky localization
  36. Fermi-GBM Sub-Threshold Detection of GRB 241112B
  37. GRB 241112B: LCO optical detection of the SVOM/VT candidate
  38. GRB 241107A: Swift/BAT candidate arcminute localization of a short burst
  39. GRB 241112B: Mephisto optical upper limits
  40. GRB 241112B: Swift ToO observations
  41. LIGO/Virgo/KAGRA S241110br: NED Galaxies in the Localization Volume
  42. LIGO/Virgo/KAGRA S241111bn: Identification of a GW compact binary merger candidate
  43. LIGO/Virgo/KAGRA S241110br: Updated Sky localization
  44. LIGO/Virgo/KAGRA S241110bk: 1 counterpart neutrino candidate event from an IceCube neutrino search
  45. LIGO/Virgo/KAGRA S241110br: Identification of a GW compact binary merger candidate
  46. LIGO/Virgo/KAGRA S241109bn: Coverage and upper limits from MAXI/GSC observations
  47. LIGO/Virgo/KAGRA S241109bn: Updated Sky localization and EM Bright Classification
  48. LIGO/Virgo/KAGRA S241109bn: Upper limits from Fermi-GBM Observations
  49. LIGO/Virgo/KAGRA S241109p: Updated Sky localization and Source Classification
  50. LIGO/Virgo/KAGRA S241109bn: Identification of a GW compact binary merger candidate
  51. LIGO/Virgo/KAGRA S241109p: Identification of a GW compact binary merger candidate
  52. GRB 241108A: Swift ToO observations
  53. GRB 241108A : a likely weak long GRB detected by SVOM/ECLAIRs
  54. EP241107a: Kinder optical follow-up observations
  55. GRB 241025A: radio detection with the VLA
  56. EP241101a: CrAO ZTSH optical observations
  57. LIGO/Virgo/KAGRA S241106ba: 1 counterpart neutrino candidate event from an IceCube neutrino search
  58. LIGO/Virgo/KAGRA S241102o: 1 counterpart neutrino candidate event from an IceCube neutrino search
  59. GRB 241104A: The SVOM/VT candidate in GCN circular 38086 is not an astrophysical source
  60. GRB 241105A: Swift ToO observations
  61. GRB 241104A: Swift ToO observations
  62. GRB 241104A: NOT optical non-detection
  63. GRB 241105A: GOTO tentative optical counterpart candidate
  64. GRB 241104A: SVOM/VT optical candidate
  65. GRB 240821A: further radio observations with the VLA
  66. EP241101a: EP-FXT observations update
  67. LIGO/Virgo/KAGRA S241104a: Retraction of GW compact binary merger candidate
  68. LIGO/Virgo/KAGRA S241102cy: Updated Sky localization
  69. LIGO/Virgo/KAGRA S241102br: Updated Sky localization
  70. EP241103a: Swift XRT detection and improved X-ray position
  71. EP241101a: Optical upper limits with Kinder observations
  72. EP241101a: OHP/T193 optical observations
  73. EP241103a: Gemini optical limits
  74. LIGO/Virgo/KAGRA S241101ee: Updated Sky localization
  75. S241102cy: Identification of a GW compact binary merger candidate
  76. LIGO/Virgo/KAGRA S241102br: NED Galaxies in the Localization Volume
  77. LIGO/Virgo/KAGRA S241102br: Identification of a GW compact binary merger candidate
  78. LIGO/Virgo/KAGRA S241101ee: Identification of a GW compact binary merger candidate
  79. GRB 241030B: Montarrenti Observatory optical upper limit
  80. GRB241030B: GRANDMA/TAROT Upper Limit
  81. GRB 241030B: Swift detection of a burst
  82. GRB 240912A: radio detection with the VLA
  83. GRB 241030A: AKO Optical Afterglow Detection
  84. GRB 241030A: Swift detection of a burst with a bright optical counterpart
  85. GRB 241029A: TRT optical afterglow candidate detection
  86. GRB 241029A: Swift ToO observations
  87. GRB 241026A: Swift detection of a burst
  88. LIGO/Virgo/KAGRA S241009l: Upper limits from Swift/BAT-GUANO
  89. EP 241021A: Swift ToO observations
  90. GRB 241025A: Swift detection of a burst with an optical counterpart
  91. GRB 241001A: ATCA radio observations
  92. EP241021a: No Detection in Fermi-GBM Observation
  93. EP241021a: Optical counterpart observations with the Liverpool Telescope
  94. EP241021a: GSP detects optical candidate counterpart
  95. EP241021a: Optical upper limits with Kinder observations
  96. IceCube-Cascade 241019A: Upper limits from a search for additional neutrino events in IceCube
  97. GRB 241018A/sb24101802: Mephisto optical upper limit
  98. GRB 241018A: REM optical/NIR upper limits
  99. GRB 241018A: NOT optical observations
  100. GRB 241018A: SVOM/VT follow-up and optical candidate

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