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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').
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"

3759 results found.

  1. Fermi GRB 241204A: Global MASTER-Net observations report
  2. Fermi-GBM Sub-Threshold Detection of GRB 241128A
  3. IceCube-241127A: Upper limits from a search for additional neutrino events in IceCube
  4. EP241201a: Global MASTER-Net observations report
  5. EP241126a: 1.6m Mephisto Optical Upper Limits
  6. LIGO/Virgo/KAGRA S241201ac: Identification of a GW compact binary merger candidate
  7. LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
  8. LIGO/Virgo/KAGRA S241130be: Identification of a GW compact binary merger candidate
  9. Swift GRB 241128A: Global MASTER-Net observations report
  10. GRB 241128A: LCO optical detection
  11. GRB 241128A: 1.5m OSN optical afterglow detection
  12. LIGO/Virgo S241127aj: GRANDMA/FRAM-CTA-N Observations
  13. Fermi trigger No 754492985: Global MASTER-Net observations report
  14. The EP-WXT trigger 01709125191 is not a real source
  15. GRB 241127A: LCOGT (40-cm) optical counterpart detection
  16. Swift GRB241127.91: Global MASTER-Net OT detection
  17. IceCube Alert 241127.59: Global MASTER-Net observations report
  18. GRB 241120A: Mondy and AbAO optical observations
  19. GRB 241112B: Mephisto further optical observations
  20. Fermi GRB 241118A: Global MASTER-Net observations report
  21. EP241115a: Global MASTER-Net observations report
  22. Fermi GRB 241114A: Global MASTER-Net observations report
  23. EP241113a: Global MASTER-Net observations report
  24. EP241113b: Global MASTER-Net observations report
  25. Fermi GRB 241112A: Global MASTER-Net observations report
  26. LIGO/Virgo/KAGRA S241109bn: Upper limits from EP-WXT observations
  27. Fermi trigger No 752878030: Global MASTER-Net observations report
  28. Integral GRB241109.89: Global MASTER-Net observations report
  29. GRB 241105A: EP-FXT follow-up observations
  30. GRB 241025A: LBT optical observations
  31. Fermi GRB 241105A: Global MASTER-Net observations report
  32. Fermi GRB 241104A: Global MASTER-Net observations report
  33. EP241103a: EP observation update
  34. LIGO/Virgo/KAGRA S241102br: MASTER observations and OT detection
  35. S241102cy: Identification of a GW compact binary merger candidate
  36. LIGO/Virgo/KAGRA S241102br: Identification of a GW compact binary merger candidate
  37. GRB 241030A: further SAO RAS optical observations
  38. GRB 241030B: Montarrenti Observatory optical upper limit
  39. Fermi trigger No 752083996: Global MASTER-Net observations report
  40. Fermi trigger No 752006065: Global MASTER-Net observations report
  41. GRB 241030B: BTA observations
  42. GRB 241026A: LBT optical observations
  43. GRB 241030A : MITSuME Akeno optical afterglow detection
  44. GRB 241026A: SAO RAS optical observations
  45. EP241021a: SAO RAS observations of rebrightening
  46. GRB 241029A: AKO Optical Afterglow Detection
  47. EP241021a: Gemini-South detection of optical rebrightening
  48. GRB 241025A: SAO RAS optical observations
  49. EP241026a (GRB 241026A): EP on-board trigger and follow-up observation
  50. GRB 241026A: COLIBRÍ Detection of the Optical Counterpart
  51. Fermi GRB 241026A: Global MASTER-Net observations report
  52. GRB 241025A: GRANDMA and Kilonova-Catcher optical afterglow detections and upperlimits
  53. Fermi trigger No 751554401: Global MASTER-Net observations report
  54. EP241021a: optical follow-up observations with the Liverpool Telescope
  55. GRB 241025A: DDOTI Afterglow detection
  56. EP241021a: GTC OSIRIS+ spectroscopy of the optical counterpart
  57. IceCube-Cascade 241019A: Upper limits from a search for additional neutrino events in IceCube
  58. GRB 241018A: SVOM/VT follow-up and optical candidate
  59. GRB 241017A: GROWTH-India Telescope optical upper limit
  60. Fermi trigger No 750788395: Global MASTER-Net observations report
  61. LIGO/Virgo/KAGRA S241011k: Identification of a GW compact binary merger candidate
  62. Fermi trigger No 750211959: Global MASTER-Net observations report
  63. Fermi trigger No 750291012: Global MASTER-Net observations report
  64. Fermi GRB 241010B: Global MASTER-Net observations report
  65. LIGO/Virgo/KAGRA S241009l: Identification of a GW compact binary merger candidate
  66. GRB 241006A: Swift/UVOT Upper Limits
  67. GRB 241001A: Swift-XRT afterglow detection
  68. GRB 240929A: SAO RAS, Mondy, and CrAO optical observations
  69. GRB 241001A: correction to GCN 37667
  70. Fermi GRB 241002B: Global MASTER-Net observations report
  71. GRB 241001A: Swift-XRT observations
  72. GRB241001A: optical afterglow candidate
  73. IceCube-240929A: Upper limits from a search for additional neutrino events in IceCube
  74. Fermi GRB 240930B: Global MASTER-Net observations report
  75. Fermi trigger No 749339671: Global MASTER-Net observations report
  76. Fermi Gamma-ray Burst Monitor trigger 749191601/240928199 is not a GRB
  77. EP240918b and EP240918c: EP-FXT follow-up observations
  78. Konus-Wind detection of GRB 240918B
  79. EP240913a/GRB 240913C: 1.6m Mephisto observations
  80. EP240919a / GRB 240919A: REM optical and NIR upper limits
  81. EP EP240918a: Global MASTER-Net observations report
  82. LIGO/Virgo/KAGRA S240910ci: Identification of a GW compact binary merger candidate
  83. EP240908a: Updates on the WXT detection result around the trigger time
  84. GRB 240905E: GIT optical upper limit
  85. GRB 240905B: Fermi-LAT detection
  86. Fermi trigger No 746923430: Global MASTER-Net observations report
  87. GRB 240828B: Mephisto optical upper limit
  88. GRB 240828B: SVOM/C-GFT optical upper limit
  89. Fermi trigger No 746587425: Global MASTER-Net observations report
  90. GRB 240828A: Fermi GBM Observation
  91. GRB 240629A: First GRB Detected by BurstCube
  92. GRB 240825A: further SAO RAS optical observations
  93. GRB 240829A: Swift detection of a burst
  94. GRB 240828A: Fermi-LAT detection
  95. LAT GRB240828.62: Global MASTER-Net observations report
  96. GRB 240828A: AstroSat CZTI detection of a long burst
  97. Fermi GRB 240828A: Global MASTER-Net observations report
  98. Fermi trigger No 746438824: Global MASTER-Net observations report
  99. SVOM GRB 240821A: optical afterglow discovery
  100. GRB 240828A: Fermi GBM Final Real-time Localization

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