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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"

32707 results found.

  1. LIGO/Virgo/KAGRA S240915b: Identification of a GW compact binary merger candidate
  2. EP240913a/GRB 240913C: KAIT optical upper limit
  3. EP240913a / GRB 240913C INTEGRAL SPI ACS LIGHT CURVE
  4. GRB 240913C: Fermi GBM detection
  5. GRB 240913C: Joint location by ETJASMIN
  6. GRB 240914B: AstroSat CZTI detection
  7. EP240913A / GRB 240913C: AstroSat CZTI detection
  8. GRB 240914A: SVOM/GRM observation
  9. GRB 240910A: SVOM/VT optical observations
  10. GRB 240914A: Swift ToO observations
  11. EP240913a: NOT optical upper limits
  12. EP240913a: JinShan optical upper limits
  13. EP240913a: ESO-NTT optical observations
  14. GRB 240914A: ESO-NTT optical observations
  15. EP240913a: Swift/XRT detection of an X-ray source within the EP/WXT error circle
  16. GRB 240905E: further NOT optical observations
  17. EP240913a: A GRB Event
  18. GRB 240911A: LCO optical observations
  19. GRB 240911A: JinShan optical upper limits on two Swift/XRT candidates
  20. Fermi Gamma-ray Burst Monitor trigger 747837485/240912526 is not a GRB
  21. GRB 240912A: Swift/UVOT Detection
  22. GRB 240911A: GOTO optical limits on Swift/XRT candidates
  23. GRB 240912A: SVOM/GRM observation
  24. Fermi GRB 240913A: Global MASTER-Net observations report
  25. GRB 240912A: J-band observations with WINTER
  26. GRB 240912A: Fermi GBM Observation
  27. Swift GRB 240912A: Global MASTER-Net observations report
  28. GRB 240912A: LCOGT detection and Legacy Surveys likely host galaxy
  29. GRB 240911A: Tiled Swift observations
  30. GRB 240912A : INTEGRAL SPI ACS LIGHT CURVE
  31. GRB 240912A: NOT optical spectroscopy
  32. GRB 240912A: Redshift from OSIRIS+/GTC
  33. Fast X-ray Transient EP240801a: GMRT radio observations
  34. GRB 240910A: Redshift from OSIRIS+/GTC
  35. GRB 240910A: Fermi GBM Observation
  36. GRB 240910A: NOT optical observations
  37. GRB 240910A: Swift-XRT detection of GOTO24fvl/AT2024vfp
  38. GRB 240910A: JinShan optical observations
  39. GRB 240910A: GOTO candidate optical counterpart
  40. EP240908a: Optical afterglow confirmation
  41. GRB 240710A: SVOM/GRM observation
  42. GRB 240910A: Swift ToO observations
  43. IPN triangulation of GRB 240905B (short)
  44. GRB 240825A: 7DT Optical Upper Limit
  45. GRB 240905E: SVOM/VT optical observations
  46. GRB 240905E: SVOM/VT optical observations (duplicate submission of GCN 37453)
  47. GRB 240910A: GRBAlpha detection
  48. LIGO/Virgo/KAGRA S240910ci: Coverage and upper limits from MAXI/GSC observations
  49. LIGO/Virgo/KAGRA S240910ci: Updated Sky localization and EM Bright Classification
  50. LIGO/Virgo/KAGRA S240910ci: Identification of a GW compact binary merger candidate
  51. GRB 240910A: SVOM/GRM observation
  52. EP240908a: Mondy and AbAO follow-up observations
  53. EP240908a: Updates on the WXT detection result around the trigger time
  54. Fermi GRB 240910A: Global MASTER-Net observations report
  55. EP240908a: optical afterglow candidate
  56. EP EP240908a: Global MASTER-Net observations report
  57. GRB 240905B: Fermi GBM Observation
  58. EP240908a: TRT optical upper limit
  59. GRB 240905B: GOTO optical upper limits
  60. Fermi GRB 240908A: Global MASTER-Net observations report
  61. LIGO/Virgo/KAGRA S240908dg: Updated Sky localization
  62. LIGO/Virgo/KAGRA S240908bs: Updated Sky localization
  63. LIGO/Virgo/KAGRA S240908dg: Identification of a GW compact binary merger candidate
  64. LIGO/Virgo/KAGRA S240908bs: Identification of a GW compact binary merger candidate
  65. LIGO/Virgo/KAGRA S240907cg: Updated Sky localization
  66. GRB 240801A: SVOM/GRM observation
  67. LIGO/Virgo/KAGRA S240907cg: Identification of a GW compact binary merger candidate
  68. GRB 240905E: GIT optical upper limit
  69. GRB 240905E: Gaoyazi/GOT optical upper limits
  70. GRB 240905E: NUTTelA-TAO / BSTI Optical Limits
  71. GRB 240905B: Fermi-LAT detection
  72. GRB 240905B: Swift ToO observations
  73. GRB 240905E: J-band observations with WINTER
  74. GRB 240905E: CrAO Optical Afterglow observations, possible OT candidate
  75. GRB 240905E: AKO Optical Upper Limit
  76. GRB 240905E: SVOM/C-GFT optical upper limit
  77. GRB 240905E: OHP/MISTRAL T193 optical upper limit
  78. Fermi GRB 240905D: Global MASTER-Net observations report
  79. Fermi GRB 240905A: Global MASTER-Net observations report
  80. GRB 240905E: NOT optical upper limits
  81. GRB 240905E: REM optical/NIR upper limits
  82. GRB 240905E: SVOM/GRM observation
  83. GRB 240905E: LCOGT Optical Upper Limit
  84. GRB 240905E: Swift/UVOT Upper Limits
  85. GRB 240905E: SAO RAS optical upper limit
  86. GRB 240825A: Montarrenti Observatory optical follow-up observations
  87. GRB 240905E: Nanshan/HMT optical upper limit
  88. Swift GRB 240905E: Global MASTER-Net observations report
  89. GRB 240819A: Optical upper limits from TESS
  90. GRB 240905D: AstroSat CZTI detection
  91. GRB 240905A: SVOM/GRM observation
  92. Fermi GRB 240905B: Global MASTER-Net observations report
  93. GRB 240905B: AstroSat CZTI detection and localization
  94. GRB 240825A: ATCA Detection of Radio Counterpart
  95. Swift GRB 240904A: Global MASTER-Net observations report
  96. GRB 240828A: SVOM/GRM observation
  97. Fermi Gamma-ray Burst Monitor trigger 240831A is not a GRB
  98. LIGO/Virgo/KAGRA S240902bq: Updated Sky localization
  99. GRB 240828A: GECAM detection
  100. LIGO/Virgo/KAGRA S240902bq: Identification of a GW compact binary merger candidate

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