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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"

26352 results found.

  1. GRB 240828A: GECAM detection
  2. LIGO/Virgo/KAGRA S240902bq: Identification of a GW compact binary merger candidate
  3. GRB 240825A: MeerLICHT afterglow detection
  4. GRB 240828A: SAO RAS AS-500(2) optical observations
  5. GRB 240821A: VLT spectroscopic observations
  6. GRB 240825A: TSHAO Optical Upper Limit
  7. GRB240828B: REM optical/NIR upper limits
  8. GRB 240828B: AbAO optical upper limit
  9. GRB 240825A: SOAR observations
  10. GRB 240828B: Mephisto optical upper limit
  11. GRB 240828B: GRANDMA Optical Upper Limit
  12. LIGO/Virgo/KAGRA S240830gn: Coverage and upper limits from MAXI/GSC observations
  13. LIGO/Virgo/KAGRA S240830gn: Updated Sky localization and EM Bright Classification
  14. GRB 240829A: Swift-BAT refined analysis
  15. GRB 240825A: Swift-BAT refined analysis
  16. LIGO/Virgo/KAGRA S240830gn: Identification of a GW compact binary merger candidate
  17. GRB 240828B: J-band upper limit from WINTER
  18. GRB 240828B: GMG Optical Upper Limit
  19. GRB 240828B: SVOM/C-GFT optical upper limit
  20. GRB 240828B: SAO RAS optical upper limit
  21. GRB 240828A: SAO RAS optical observations
  22. Fermi trigger No 746587425: Global MASTER-Net observations report
  23. GRB 240828A: Fermi GBM Observation
  24. GRB 240828A: KAIT Optical Afterglow Candidate
  25. GRB 240825A: SVOM/VT optical detection
  26. GRB 240828A: Swift-XRT afterglow detection
  27. GRB 240825A: further SAO RAS optical observations
  28. GRB 240825A: iTelescope optical observations
  29. GRB 240828B: Swift-XRT afterglow detection
  30. GRB 240829A: Swift detection of a burst
  31. Fermi GRB 240828A: Bassano Bresciano Observatory upper limit
  32. GRB 240825A: Upper limits from a neutrino search with IceCube
  33. GRB 240821A: PRIME near-infrared observations
  34. GRB 240828B : Detection of a possible very soft X-ray transient by SVOM/ECLAIRs
  35. GRB 240821A: the second and third EP-FXT follow-up observations and afterglow candidates
  36. GRB 240825A: SAO RAS optical observations
  37. GRB 240824A: GIT optical upper limit
  38. LIGO/Virgo/KAGRA S240825ar: Updated Sky localization
  39. LIGO/Virgo/KAGRA S240825ar: Updated Sky localization
  40. GRB 240825A: NUTTelA-TAO / BSTI Optical Limits
  41. GRB 240825A: GMG Continued Optical Observation on the Second Night
  42. GRB 240825A: PRIME near-infrared detection
  43. GRB 240825A: Fermi GBM Observation
  44. GRB 240825A : MISTRAL/T193 OHP optical follow-up of the afterglow
  45. SGR 1E 1841-045 / Kes 73: SVOM/GRM observation
  46. GRB 240825A: Swift/UVOT Detection
  47. GRB 240825A: REM detection of the optical/NIR afterglow
  48. GRB 240825A: Swift-XRT refined Analysis
  49. GRB 240825A: VLT/X-shooter redshift
  50. GRB 240825A: Montarrenti Observatory optical observations
  51. GRB 240825A: Enhanced Swift-XRT position
  52. GRB 240825A: LCO optical observations
  53. GRB 240824B: KAIT optical upper limit
  54. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  55. GRB 240824B: Fermi GBM Observation
  56. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  57. GRB 240824B: NOT optical upper limit
  58. GRB 240825A: GMG Optical Observation
  59. GRB 240825A: 1.6m Mephisto multi-band detection
  60. GRB 240825A: AKO Optical Afterglow Detection
  61. GRB 240825A: Skynet Optical Afterglow observations
  62. GRB 240825A: Nanshan/HMT optical afterglow observations
  63. GRB 240825A: Swift detection of a burst with a bright optical counterpart
  64. GRB 240824A: Swift-BAT refined analysis
  65. GRB 240824A: SVOM/C-GFT optical upper limit
  66. GRB 240824B: Swift-XRT afterglow detection
  67. GRB 240824A: Swift-XRT observations
  68. LIGO/Virgo/KAGRA S240825ar: Identification of a GW compact binary merger candidate
  69. GRB 240824A: Swift/UVOT Upper Limits
  70. GRB 240821A: Swift/UVOT observations of the XRT sources.
  71. GRB 240824B: MAXI/GSC detection
  72. GRB240824A: GRANDMA/TAROT-TCA Upper Limit
  73. SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
  74. GRB 240824A: Skynet Optical Afterglow Discovery
  75. GRB 240824A: Swift detection of a burst
  76. SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
  77. GRB 240821A: Colibri Optical Upper Limit
  78. EP240820a: PRIME J-band Observations
  79. GRB 240821A: Swift-XRT observations
  80. GRB 240822A: AstroSat CZTI detection of a short burst
  81. GRB 240821A: REM optical/NIR upper limits
  82. GRB 240821A: LCO optical observations
  83. GRB 240821A: JinShan optical upper limits
  84. GRB 240809A: Mondy and AbAO Optical Observations
  85. GRB 240821A: GMG Optical Upper Limit
  86. Fermi GRB 240821A: Global MASTER-Net observations report
  87. GECAM-B observation of a short burst from SGR 1E 1841-045 / Kes 73
  88. GRB 240821A: Fermi GBM Observation
  89. Fermi trigger No 745925274: Global MASTER-Net observations report
  90. Fermi trigger No 745935375: Global MASTER-Net observations report
  91. GRB240821A: EIRSAT-1 GMOD Detection
  92. GRB240821B: First GRB Detected by EIRSAT-1 GMOD
  93. GRB 240821A: SVOM/GRM observation
  94. GRB 240821A: SVOM/GRM observation
  95. GRB 240821A: GRANDMA/LesMakes-T60 Upper Limit
  96. Fermi trigger No 745866488: Global MASTER-Net observations report
  97. GRB 240821A: BALROG localization (Fermi Trigger 745958167 / GRB 240821775)
  98. GRB 240821A : a likely short GRB detected by SVOM/ECLAIRs
  99. GRB 240819A: Swift-XRT observations
  100. GRB 240819A: JinShan optical upper limits on one Swift/XRT source

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