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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"

32693 results found.

  1. EP240913a: Swift/XRT detection of an X-ray source within the EP/WXT error circle
  2. GRB 240905E: further NOT optical observations
  3. EP240913a: A GRB Event
  4. GRB 240911A: LCO optical observations
  5. GRB 240911A: JinShan optical upper limits on two Swift/XRT candidates
  6. Fermi Gamma-ray Burst Monitor trigger 747837485/240912526 is not a GRB
  7. GRB 240912A: Swift/UVOT Detection
  8. GRB 240911A: GOTO optical limits on Swift/XRT candidates
  9. GRB 240912A: SVOM/GRM observation
  10. Fermi GRB 240913A: Global MASTER-Net observations report
  11. GRB 240912A: J-band observations with WINTER
  12. GRB 240912A: Fermi GBM Observation
  13. Swift GRB 240912A: Global MASTER-Net observations report
  14. GRB 240912A: LCOGT detection and Legacy Surveys likely host galaxy
  15. GRB 240911A: Tiled Swift observations
  16. GRB 240912A : INTEGRAL SPI ACS LIGHT CURVE
  17. GRB 240912A: NOT optical spectroscopy
  18. GRB 240912A: Redshift from OSIRIS+/GTC
  19. Fast X-ray Transient EP240801a: GMRT radio observations
  20. GRB 240910A: Redshift from OSIRIS+/GTC
  21. GRB 240910A: Fermi GBM Observation
  22. GRB 240910A: NOT optical observations
  23. GRB 240910A: Swift-XRT detection of GOTO24fvl/AT2024vfp
  24. GRB 240910A: JinShan optical observations
  25. GRB 240910A: GOTO candidate optical counterpart
  26. EP240908a: Optical afterglow confirmation
  27. GRB 240710A: SVOM/GRM observation
  28. GRB 240910A: Swift ToO observations
  29. IPN triangulation of GRB 240905B (short)
  30. GRB 240825A: 7DT Optical Upper Limit
  31. GRB 240905E: SVOM/VT optical observations
  32. GRB 240905E: SVOM/VT optical observations (duplicate submission of GCN 37453)
  33. GRB 240910A: GRBAlpha detection
  34. LIGO/Virgo/KAGRA S240910ci: Coverage and upper limits from MAXI/GSC observations
  35. LIGO/Virgo/KAGRA S240910ci: Updated Sky localization and EM Bright Classification
  36. LIGO/Virgo/KAGRA S240910ci: Identification of a GW compact binary merger candidate
  37. GRB 240910A: SVOM/GRM observation
  38. EP240908a: Mondy and AbAO follow-up observations
  39. EP240908a: Updates on the WXT detection result around the trigger time
  40. Fermi GRB 240910A: Global MASTER-Net observations report
  41. EP240908a: optical afterglow candidate
  42. EP EP240908a: Global MASTER-Net observations report
  43. GRB 240905B: Fermi GBM Observation
  44. EP240908a: TRT optical upper limit
  45. GRB 240905B: GOTO optical upper limits
  46. Fermi GRB 240908A: Global MASTER-Net observations report
  47. LIGO/Virgo/KAGRA S240908dg: Updated Sky localization
  48. LIGO/Virgo/KAGRA S240908bs: Updated Sky localization
  49. LIGO/Virgo/KAGRA S240908dg: Identification of a GW compact binary merger candidate
  50. LIGO/Virgo/KAGRA S240908bs: Identification of a GW compact binary merger candidate
  51. LIGO/Virgo/KAGRA S240907cg: Updated Sky localization
  52. GRB 240801A: SVOM/GRM observation
  53. LIGO/Virgo/KAGRA S240907cg: Identification of a GW compact binary merger candidate
  54. GRB 240905E: GIT optical upper limit
  55. GRB 240905E: Gaoyazi/GOT optical upper limits
  56. GRB 240905E: NUTTelA-TAO / BSTI Optical Limits
  57. GRB 240905B: Fermi-LAT detection
  58. GRB 240905B: Swift ToO observations
  59. GRB 240905E: J-band observations with WINTER
  60. GRB 240905E: CrAO Optical Afterglow observations, possible OT candidate
  61. GRB 240905E: AKO Optical Upper Limit
  62. GRB 240905E: SVOM/C-GFT optical upper limit
  63. GRB 240905E: OHP/MISTRAL T193 optical upper limit
  64. Fermi GRB 240905D: Global MASTER-Net observations report
  65. Fermi GRB 240905A: Global MASTER-Net observations report
  66. GRB 240905E: NOT optical upper limits
  67. GRB 240905E: REM optical/NIR upper limits
  68. GRB 240905E: SVOM/GRM observation
  69. GRB 240905E: LCOGT Optical Upper Limit
  70. GRB 240905E: Swift/UVOT Upper Limits
  71. GRB 240905E: SAO RAS optical upper limit
  72. GRB 240825A: Montarrenti Observatory optical follow-up observations
  73. GRB 240905E: Nanshan/HMT optical upper limit
  74. Swift GRB 240905E: Global MASTER-Net observations report
  75. GRB 240819A: Optical upper limits from TESS
  76. GRB 240905D: AstroSat CZTI detection
  77. GRB 240905A: SVOM/GRM observation
  78. Fermi GRB 240905B: Global MASTER-Net observations report
  79. GRB 240905B: AstroSat CZTI detection and localization
  80. GRB 240825A: ATCA Detection of Radio Counterpart
  81. Swift GRB 240904A: Global MASTER-Net observations report
  82. GRB 240828A: SVOM/GRM observation
  83. Fermi Gamma-ray Burst Monitor trigger 240831A is not a GRB
  84. LIGO/Virgo/KAGRA S240902bq: Updated Sky localization
  85. GRB 240828A: GECAM detection
  86. LIGO/Virgo/KAGRA S240902bq: Identification of a GW compact binary merger candidate
  87. GRB 240825A: Magnitude Correction in SVOM/C-GFT Optical Observations
  88. GRB 240825A: MeerLICHT afterglow detection
  89. GRB 240828A: SAO RAS AS-500(2) optical observations
  90. GRB 240821A: VLT spectroscopic observations
  91. GRB 240825A: TSHAO Optical Upper Limit
  92. GRB 240829B: GRBAlpha detection
  93. GRB240828B: REM optical/NIR upper limits
  94. GRB 240828B: AbAO optical upper limit
  95. GRB 240825A: SOAR observations
  96. GRB 240828B: Mephisto optical upper limit
  97. GRB 240828B: GRANDMA Optical Upper Limit
  98. LIGO/Virgo/KAGRA S240830gn: Coverage and upper limits from MAXI/GSC observations
  99. LIGO/Virgo/KAGRA S240830gn: Updated Sky localization and EM Bright Classification
  100. GRB 240829A: Swift-BAT refined analysis

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