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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.

Advanced Search Examples (click to copy):

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

25029 results found.

  1. GRB 240828A: Fermi GBM Observation
  2. GRB 240828A: KAIT Optical Afterglow Candidate
  3. GRB 240825A: SVOM/VT optical detection
  4. GRB 240828A: Swift-XRT afterglow detection
  5. GRB 240825A: further SAO RAS optical observations
  6. GRB 240825A: iTelescope optical observations
  7. GRB 240828B: Swift-XRT afterglow detection
  8. GRB 240829A: Swift detection of a burst
  9. Fermi GRB 240828A: Bassano Bresciano Observatory upper limit
  10. GRB 240825A: Upper limits from a neutrino search with IceCube
  11. GRB 240821A: PRIME near-infrared observations
  12. GRB 240828B : Detection of a possible very soft X-ray transient by SVOM/ECLAIRs
  13. GRB 240821A: the second and third EP-FXT follow-up observations and afterglow candidates
  14. GRB 240825A: SAO RAS optical observations
  15. GRB 240824A: GIT optical upper limit
  16. LIGO/Virgo/KAGRA S240825ar: Updated Sky localization
  17. LIGO/Virgo/KAGRA S240825ar: Updated Sky localization
  18. GRB 240825A: NUTTelA-TAO / BSTI Optical Limits
  19. GRB 240825A: GMG Continued Optical Observation on the Second Night
  20. GRB 240825A: PRIME near-infrared detection
  21. GRB 240825A: Fermi GBM Observation
  22. GRB 240825A : MISTRAL/T193 OHP optical follow-up of the afterglow
  23. SGR 1E 1841-045 / Kes 73: SVOM/GRM observation
  24. GRB 240825A: Swift/UVOT Detection
  25. GRB 240825A: REM detection of the optical/NIR afterglow
  26. GRB 240825A: Swift-XRT refined Analysis
  27. GRB 240825A: VLT/X-shooter redshift
  28. GRB 240825A: Montarrenti Observatory optical observations
  29. GRB 240825A: Enhanced Swift-XRT position
  30. GRB 240825A: LCO optical observations
  31. GRB 240824B: KAIT optical upper limit
  32. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  33. GRB 240824B: Fermi GBM Observation
  34. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  35. GRB 240824B: NOT optical upper limit
  36. GRB 240825A: GMG Optical Observation
  37. GRB 240825A: 1.6m Mephisto multi-band detection
  38. GRB 240825A: AKO Optical Afterglow Detection
  39. GRB 240825A: Skynet Optical Afterglow observations
  40. GRB 240825A: Nanshan/HMT optical afterglow observations
  41. GRB 240825A: Swift detection of a burst with a bright optical counterpart
  42. GRB 240824A: Swift-BAT refined analysis
  43. GRB 240824A: SVOM/C-GFT optical upper limit
  44. GRB 240824B: Swift-XRT afterglow detection
  45. GRB 240824A: Swift-XRT observations
  46. LIGO/Virgo/KAGRA S240825ar: Identification of a GW compact binary merger candidate
  47. GRB 240824A: Swift/UVOT Upper Limits
  48. GRB 240821A: Swift/UVOT observations of the XRT sources.
  49. GRB 240824B: MAXI/GSC detection
  50. GRB240824A: GRANDMA/TAROT-TCA Upper Limit
  51. SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
  52. GRB 240824A: Skynet Optical Afterglow Discovery
  53. GRB 240824A: Swift detection of a burst
  54. SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
  55. GRB 240821A: Colibri Optical Upper Limit
  56. EP240820a: PRIME J-band Observations
  57. GRB 240821A: Swift-XRT observations
  58. GRB 240822A: AstroSat CZTI detection of a short burst
  59. GRB 240821A: REM optical/NIR upper limits
  60. GRB 240821A: LCO optical observations
  61. GRB 240821A: JinShan optical upper limits
  62. GRB 240809A: Mondy and AbAO Optical Observations
  63. GRB 240821A: GMG Optical Upper Limit
  64. Fermi GRB 240821A: Global MASTER-Net observations report
  65. GECAM-B observation of a short burst from SGR 1E 1841-045 / Kes 73
  66. GRB 240821A: Fermi GBM Observation
  67. Fermi trigger No 745925274: Global MASTER-Net observations report
  68. Fermi trigger No 745935375: Global MASTER-Net observations report
  69. GRB240821A: EIRSAT-1 GMOD Detection
  70. GRB240821B: First GRB Detected by EIRSAT-1 GMOD
  71. GRB 240821A: SVOM/GRM observation
  72. GRB 240821A: SVOM/GRM observation
  73. GRB 240821A: GRANDMA/LesMakes-T60 Upper Limit
  74. Fermi trigger No 745866488: Global MASTER-Net observations report
  75. GRB 240821A: BALROG localization (Fermi Trigger 745958167 / GRB 240821775)
  76. GRB 240821A : a likely short GRB detected by SVOM/ECLAIRs
  77. GRB 240819A: Swift-XRT observations
  78. GRB 240819A: JinShan optical upper limits on one Swift/XRT source
  79. EP240820a: TRT optical upper limit
  80. EP240820a: EP detection of a fast X-ray transient
  81. EP240816a: PRIME upper limits
  82. Fermi trigger No 745873283: Global MASTER-Net observations report
  83. GRB 240819A : an X-ray transient detected by SVOM/ECLAIRs
  84. GRB 240819A: TRT optical upper limits on the Swift/XRT and EP/FXT sources
  85. EP240816b: Liverpool Telescope optical follow-up observations
  86. GRB 240805B: Osservatorio Astronomico Nastro Verde upper limit
  87. EP240816a: EP detection of a fast X-ray transient and follow-up observation
  88. EP240816b: TRT optical upper limit
  89. EP240816b: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  90. EP240802a: Kinder optical, SWIFT-UVOT, and SWIFT-XRT upper limits 6 days after the WXT detection
  91. LIGO/Virgo/KAGRA S240813d: Updated Sky localization
  92. LIGO/Virgo/KAGRA S240813d: Identification of a GW compact binary merger candidate
  93. LIGO/Virgo/KAGRA S240813c: Updated Sky localization
  94. LIGO/Virgo/KAGRA S240813c: Identification of a GW compact binary merger candidate
  95. GRB 240810A: SVOM/GRM observation
  96. GRB 240809A : RAPAS follow-up observations
  97. GRB 240811A: Swift-BAT refined analysis
  98. GRB 240809A: Swift-BAT refined analysis
  99. EP240807a: PRIME H-band upper limits
  100. IceCube-240808A: Upper limits from a search for additional neutrino events in IceCube

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