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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"

4716 results found.

  1. Fermi GRB 241105A: Global MASTER-Net observations report
  2. EP241103a: GIT optical upper limit
  3. EP241021a: OHP/T193 further optical observations
  4. LIGO/Virgo/KAGRA S241102br: OHP/T193 optical observations
  5. EP241103a: GOTO optical upper limit
  6. EP241103a: Swift XRT detection and improved X-ray position
  7. LIGO/Virgo/KAGRA S241102br: MASTER observations and OT detection
  8. EP241103a: GSP optical upper limit
  9. EP241103A: LCO optical observations
  10. EP241103a: Global MASTER-Net observations report
  11. GRB 241030A: Rapid release of TESS data.
  12. GRB241030A: OHP/T193 optical observations
  13. Fermi trigger No 752083996: Global MASTER-Net observations report
  14. EP EP241030a: Global MASTER-Net observations report
  15. Fermi trigger No 752006065: Global MASTER-Net observations report
  16. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  17. GRB 241030B: AKO Optical Afterglow Detection
  18. GRB 241030B: Prompt enhanced Swift-XRT position
  19. GRB 241030A: Fermi-LAT detection
  20. GRB 241026A: LBT optical observations
  21. GRB 241030A: SVOM/VT optical afterglow observations
  22. GRB 241030A: ULL-ASTRO-MASTER detection of a bright optical counterpart with the LCOGT 40-cm telescope at McDonald Observatory
  23. GRB 241030A: Swift detection of a burst with a bright optical counterpart
  24. GRB 241030A: Fermi GBM Final Real-time Localization
  25. EP241021a: SAO RAS observations of rebrightening
  26. GRB 241029A: GOTO optical afterglow detection
  27. EP 241026b: LBT possible optical counterpart (brightening source)
  28. EP EP241026b: Global MASTER-Net observations report
  29. Fermi GRB 241026A: Global MASTER-Net observations report
  30. GRB 241025A: COLIBRÍ Detection of the Afterglow
  31. Fermi GRB 241025A: Global MASTER-Net observations report
  32. GRB 241025A : SVOM/VT optical afterglow observations
  33. Fermi trigger No 750788395: Global MASTER-Net observations report
  34. Fermi GRB 241016A: Global MASTER-Net observations report
  35. IceCube Alert 241016.04: Global MASTER-Net observations report
  36. GRB 241009A: LCO optical upper limits
  37. GRB 241006A: ATCA Radio Upper Limits
  38. Fermi trigger No 750211959: Global MASTER-Net observations report
  39. GRB 240821A: Host galaxy redshift from VLT/X-shooter
  40. IceCube Alert 241006.94: Global MASTER-Net observations report
  41. Fermi trigger No 749721670: Global MASTER-Net observations report
  42. Fermi trigger No 749630753: Global MASTER-Net observations report
  43. GRB 241001A : SVOM/VT optical detection
  44. GRB 241002B: GOTO24gpc/AT 2024xbg follow-up observations update
  45. NuEm-240926A: Upper limits from a search for coincident neutrino events in IceCube
  46. GRB 241002B: GOTO optical counterpart candidate
  47. GRB 241002A: 1.5m OSN optical upper limit
  48. LIGO/Virgo/KAGRA S241002e: Identification of a GW compact binary merger candidate
  49. EP EP240930a: Global MASTER-Net observations report
  50. LIGO/Virgo/KAGRA S240930aa: Identification of a GW compact binary merger candidate
  51. Fermi GRB 240929A: Global MASTER-Net observations report
  52. LIGO/Virgo/KAGRA S240924a: Identification of a GW compact binary merger candidate
  53. LIGO/Virgo S240919bn: GOTO optical upper limits
  54. EP240919a / GRB 240919A: KAIT optical upper limit
  55. EP240919a: GOTO optical upper limits
  56. EP EP240918a: Global MASTER-Net observations report
  57. GRB 240916A: NOT optical observation
  58. GRB 240913B: Fermi GBM Final Real-time Localization
  59. Fermi GRB 240913A: Global MASTER-Net observations report
  60. GRB 240913A: Fermi GBM Final Real-time Localization
  61. GRB 240905E: NUTTelA-TAO / BSTI Optical Limits
  62. GRB 240905E: CrAO Optical Afterglow observations, possible OT candidate
  63. GRB 240905E: Swift-XRT refined Analysis
  64. GRB 240905E: Swift detection of a burst
  65. GRB 240825A: MeerLICHT afterglow detection
  66. Fermi trigger No 746882332: Global MASTER-Net observations report
  67. Fermi trigger No 746587425: Global MASTER-Net observations report
  68. GRB 240828A: KAIT Optical Afterglow Candidate
  69. GRB 240825A: iTelescope optical observations
  70. GRB 240829A: Swift detection of a burst
  71. Swift GRB240829.16: Global MASTER-Net observations report
  72. LAT GRB240828.62: Global MASTER-Net observations report
  73. Fermi GRB 240828A: Global MASTER-Net observations report
  74. Fermi trigger No 746438824: Global MASTER-Net observations report
  75. GRB 240825A: ALMA detection
  76. GRB 240825A: SAO RAS optical observations
  77. GRB 240825A: VLT/X-shooter redshift
  78. GRB 240824A: KAIT optical upper limit
  79. GRB 240824A: Swift detection of a burst
  80. GRB 240821A: Swift-XRT observations
  81. Fermi GRB 240821A: Global MASTER-Net observations report
  82. Fermi trigger No 746019401: Global MASTER-Net observations report
  83. Fermi trigger No 745935375: Global MASTER-Net observations report
  84. Trigger 1249878: Swift detection of another burst from SGR 1E 1841-045 / Kes 73
  85. GRB 240819A: Swift-XRT observations
  86. EP240820a: TRT optical upper limit
  87. GRB 240819A: KAIT optical upper limit
  88. EP240816b: Liverpool Telescope optical follow-up observations
  89. GRB 240814A: Fermi GBM Final Real-time Localization
  90. LIGO/Virgo/KAGRA S240813c: Identification of a GW compact binary merger candidate
  91. GRB 240812D: Fermi GBM Final Real-time Localization
  92. EP240801a: Assy-Turgen optical observations
  93. Fermi trigger No 745057312: Global MASTER-Net observations report
  94. EP240807a: STEP/T80S optical limits
  95. EP EP240807a: Global MASTER-Net observations report
  96. EP EP240806a: Global MASTER-Net observations report
  97. GRB 240801A: GRBAlpha detection
  98. The EP-WXT trigger 01709018832 on August 7th is likely a flaring star
  99. Fermi trigger No 744629911: Global MASTER-Net observations report
  100. Improved IPN triangulation of GRB 240802A / EP 240802a

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