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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

32756 results found.

  1. GRB 240910A: SVOM/GRM observation
  2. EP240908a: Mondy and AbAO follow-up observations
  3. EP240908a: Updates on the WXT detection result around the trigger time
  4. Fermi GRB 240910A: Global MASTER-Net observations report
  5. EP240908a: optical afterglow candidate
  6. EP EP240908a: Global MASTER-Net observations report
  7. GRB 240905B: Fermi GBM Observation
  8. EP240908a: TRT optical upper limit
  9. GRB 240905B: GOTO optical upper limits
  10. Fermi GRB 240908A: Global MASTER-Net observations report
  11. LIGO/Virgo/KAGRA S240908dg: Updated Sky localization
  12. LIGO/Virgo/KAGRA S240908bs: Updated Sky localization
  13. LIGO/Virgo/KAGRA S240908dg: Identification of a GW compact binary merger candidate
  14. LIGO/Virgo/KAGRA S240908bs: Identification of a GW compact binary merger candidate
  15. LIGO/Virgo/KAGRA S240907cg: Updated Sky localization
  16. GRB 240801A: SVOM/GRM observation
  17. LIGO/Virgo/KAGRA S240907cg: Identification of a GW compact binary merger candidate
  18. GRB 240905E: GIT optical upper limit
  19. GRB 240905E: Gaoyazi/GOT optical upper limits
  20. GRB 240905E: NUTTelA-TAO / BSTI Optical Limits
  21. GRB 240905B: Fermi-LAT detection
  22. GRB 240905B: Swift ToO observations
  23. GRB 240905E: J-band observations with WINTER
  24. GRB 240905E: CrAO Optical Afterglow observations, possible OT candidate
  25. GRB 240905E: AKO Optical Upper Limit
  26. GRB 240905E: SVOM/C-GFT optical upper limit
  27. GRB 240905E: OHP/MISTRAL T193 optical upper limit
  28. Fermi GRB 240905D: Global MASTER-Net observations report
  29. Fermi GRB 240905A: Global MASTER-Net observations report
  30. GRB 240905E: NOT optical upper limits
  31. GRB 240905E: REM optical/NIR upper limits
  32. GRB 240905E: SVOM/GRM observation
  33. GRB 240905E: LCOGT Optical Upper Limit
  34. GRB 240905E: Swift/UVOT Upper Limits
  35. GRB 240905E: SAO RAS optical upper limit
  36. GRB 240825A: Montarrenti Observatory optical follow-up observations
  37. GRB 240905E: Nanshan/HMT optical upper limit
  38. Swift GRB 240905E: Global MASTER-Net observations report
  39. GRB 240819A: Optical upper limits from TESS
  40. GRB 240905D: AstroSat CZTI detection
  41. GRB 240905A: SVOM/GRM observation
  42. Fermi GRB 240905B: Global MASTER-Net observations report
  43. GRB 240905B: AstroSat CZTI detection and localization
  44. GRB 240825A: ATCA Detection of Radio Counterpart
  45. Swift GRB 240904A: Global MASTER-Net observations report
  46. GRB 240828A: SVOM/GRM observation
  47. Fermi Gamma-ray Burst Monitor trigger 240831A is not a GRB
  48. LIGO/Virgo/KAGRA S240902bq: Updated Sky localization
  49. GRB 240828A: GECAM detection
  50. LIGO/Virgo/KAGRA S240902bq: Identification of a GW compact binary merger candidate
  51. GRB 240825A: Magnitude Correction in SVOM/C-GFT Optical Observations
  52. GRB 240825A: MeerLICHT afterglow detection
  53. GRB 240828A: SAO RAS AS-500(2) optical observations
  54. GRB 240821A: VLT spectroscopic observations
  55. GRB 240825A: TSHAO Optical Upper Limit
  56. GRB 240829B: GRBAlpha detection
  57. GRB240828B: REM optical/NIR upper limits
  58. GRB 240828B: AbAO optical upper limit
  59. GRB 240825A: SOAR observations
  60. GRB 240828B: Mephisto optical upper limit
  61. GRB 240828B: GRANDMA Optical Upper Limit
  62. LIGO/Virgo/KAGRA S240830gn: Coverage and upper limits from MAXI/GSC observations
  63. LIGO/Virgo/KAGRA S240830gn: Updated Sky localization and EM Bright Classification
  64. GRB 240829A: Swift-BAT refined analysis
  65. GRB 240825A: Swift-BAT refined analysis
  66. LIGO/Virgo/KAGRA S240830gn: Identification of a GW compact binary merger candidate
  67. GRB 240825A: MeerKAT detection
  68. GRB 240828B: J-band upper limit from WINTER
  69. GRB 240828B: GMG Optical Upper Limit
  70. GRB 240828A: KAIT continued optical observations
  71. GRB 240828B: GWAC-F50A optical upper limit
  72. GRB 240828B: SVOM/C-GFT optical upper limit
  73. GRB 240828B: SAO RAS optical upper limit
  74. GRB 240828B: KAIT optical upper limit
  75. GRB 240828A: SAO RAS optical observations
  76. GRB 240828A: Fermi GBM Observation
  77. GRB 240629A: First GRB Detected by BurstCube
  78. GRB 240828A: KAIT Optical Afterglow Candidate
  79. GRB 240825A: SVOM/VT optical detection
  80. GRB 240825A: further SAO RAS optical observations
  81. GRB 240825A: iTelescope optical observations
  82. GRB 240828A: Fermi-LAT detection
  83. GRB 240828A: Tiled Swift observations
  84. GRB 240828A: AstroSat CZTI detection of a long burst
  85. GRB 240825A: Upper limits from a neutrino search with IceCube
  86. GRB 240819A as a likely X-Ray Flash
  87. GRB 240828B: Swift ToO observations
  88. GRB 240821A: PRIME near-infrared observations
  89. GRB 240825A: VLA detection
  90. Fermi GRB 240828A: Global MASTER-Net observations report
  91. SVOM GRB 240821A: optical afterglow discovery
  92. GRB 240821A: the second and third EP-FXT follow-up observations and afterglow candidates
  93. GRB 240825A: GECAM detection
  94. GRB 240825A: ALMA detection
  95. GRB 240825A: SAO RAS optical observations
  96. GRB 240824A: GIT optical upper limit
  97. GRB 240819A: Swift afterglow confirmation
  98. GRB 240825A: TNG optical photometry and spectroscopy
  99. LIGO/Virgo/KAGRA S240825ar: Updated Sky localization
  100. LIGO/Virgo/KAGRA S240825ar: Updated Sky localization

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