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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"

32757 results found.

  1. GRB 240919A / EP240919a: SVOM/GRM observation
  2. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  3. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  4. LIGO/Virgo/KAGRA S240920dw: Identification of a GW compact binary merger candidate
  5. EP EP240919a: Global MASTER-Net observations report
  6. GRB 240910A: radio detection with the VLA
  7. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  8. EP240919a: NOT and Gemini optical observations
  9. EP240919a: GOTO optical upper limits
  10. EP240919a: JinShan optical upper limits
  11. EP240919a is likely a GRB event (duplicate submission of 37563)
  12. EP240919a is likely a GRB event
  13. LIGO/Virgo/KAGRA S240920bz: Identification of a GW compact binary merger candidate
  14. GRB 240918A and GRB 240918B : INTEGRAL SPI ACS LIGHT CURVE
  15. LIGO/Virgo/KAGRA S240919bn: Updated Sky localization
  16. GRB 240918B: Fermi GBM Detection
  17. LIGO/Virgo/KAGRA S240917cb: Updated Sky localization and EM Bright Classification
  18. LIGO/Virgo/KAGRA S240916ar: Updated Sky localization and EM Bright Classification
  19. EP240918a: EP observation update
  20. GRB 240910A: further Swift observations and confirmation of afterglow
  21. LIGO/Virgo/KAGRA S240919bn: Identification of a GW compact binary merger candidate
  22. EP240918a: Swift-XRT observation
  23. Fermi GRB 240918A: Global MASTER-Net observations report
  24. EP EP240918a: Global MASTER-Net observations report
  25. EP240918a: JinShan optical upper limits
  26. EP240918a: YAHPT Optical Upper Limit
  27. EP240918a: Optical upper limits with Kinder observations
  28. EP240918a: GMG Optical Upper Limit
  29. GRB 240916A: GRBAlpha detection
  30. GRB 240914B: GRBAlpha detection
  31. GRB 240916A: NOT optical observation
  32. GRB 240912A: Swift-BAT refined analysis
  33. IPN triangulation of GRB 240913C / EP 240913a
  34. GRB 240825A: INTEGRAL SPI ACS LIGHT CURVE
  35. GRB 240825A: The nature of the afterglow motivates the search of the associated supernova
  36. GRB 240916A: Fermi GBM Observation
  37. LIGO/Virgo/KAGRA S240917cb: Identification of a GW compact binary merger candidate
  38. GRB 240821A: radio observation with the VLA
  39. GRB 240916A (AT 2024vlp / GOTO24fzn): VLT/X-shooter redshift
  40. GRB 240916A: Swift-XRT afterglow detection
  41. LIGO/Virgo/KAGRA S240916ar: Identification of a GW compact binary merger candidate
  42. GRB 240916A: Swift ToO observations
  43. GRB 240916A: JinShan optical decay in one of the two GOTO candidates
  44. GRB 240916A: GOTO identification of two new optical sources within the GBM localisation region
  45. EP EP240913a: Global MASTER-Net observations report
  46. LIGO/Virgo/KAGRA S240915b: Coverage and upper limits from MAXI/GSC observations
  47. GRB 240916A INTEGRAL SPI ACS LIGHT CURVE
  48. LIGO/Virgo/KAGRA S240915bd: Updated Sky localization
  49. EP240913a: VLT/HAWK-I near-infrared upper limits
  50. LIGO/Virgo/KAGRA S240915bd: Identification of a GW compact binary merger candidate
  51. LIGO/Virgo/KAGRA S240915b: Updated Sky localization and EM Bright Classification
  52. LIGO/Virgo/KAGRA S240915b: Identification of a GW compact binary merger candidate
  53. EP240913a/GRB 240913C: KAIT optical upper limit
  54. EP240913a / GRB 240913C INTEGRAL SPI ACS LIGHT CURVE
  55. GRB 240913C: Fermi GBM detection
  56. GRB 240913C: Joint location by ETJASMIN
  57. GRB 240914B: AstroSat CZTI detection
  58. EP240913A / GRB 240913C: AstroSat CZTI detection
  59. GRB 240914A: SVOM/GRM observation
  60. GRB 240910A: SVOM/VT optical observations
  61. GRB 240914A: Swift ToO observations
  62. EP240913a: NOT optical upper limits
  63. EP240913a: JinShan optical upper limits
  64. EP240913a: ESO-NTT optical observations
  65. GRB 240914A: ESO-NTT optical observations
  66. EP240913a: Swift/XRT detection of an X-ray source within the EP/WXT error circle
  67. GRB 240905E: further NOT optical observations
  68. EP240913a: A GRB Event
  69. GRB 240911A: LCO optical observations
  70. GRB 240911A: JinShan optical upper limits on two Swift/XRT candidates
  71. Fermi Gamma-ray Burst Monitor trigger 747837485/240912526 is not a GRB
  72. GRB 240912A: Swift/UVOT Detection
  73. GRB 240911A: GOTO optical limits on Swift/XRT candidates
  74. GRB 240912A: SVOM/GRM observation
  75. Fermi GRB 240913A: Global MASTER-Net observations report
  76. GRB 240912A: J-band observations with WINTER
  77. GRB 240912A: Fermi GBM Observation
  78. Swift GRB 240912A: Global MASTER-Net observations report
  79. GRB 240912A: LCOGT detection and Legacy Surveys likely host galaxy
  80. GRB 240911A: Tiled Swift observations
  81. GRB 240912A : INTEGRAL SPI ACS LIGHT CURVE
  82. GRB 240912A: NOT optical spectroscopy
  83. GRB 240912A: Redshift from OSIRIS+/GTC
  84. Fast X-ray Transient EP240801a: GMRT radio observations
  85. GRB 240910A: Redshift from OSIRIS+/GTC
  86. GRB 240910A: Fermi GBM Observation
  87. GRB 240910A: NOT optical observations
  88. GRB 240910A: Swift-XRT detection of GOTO24fvl/AT2024vfp
  89. GRB 240910A: JinShan optical observations
  90. GRB 240910A: GOTO candidate optical counterpart
  91. EP240908a: Optical afterglow confirmation
  92. GRB 240710A: SVOM/GRM observation
  93. GRB 240910A: Swift ToO observations
  94. IPN triangulation of GRB 240905B (short)
  95. GRB 240825A: 7DT Optical Upper Limit
  96. GRB 240905E: SVOM/VT optical observations
  97. GRB 240905E: SVOM/VT optical observations (duplicate submission of GCN 37453)
  98. GRB 240910A: GRBAlpha detection
  99. LIGO/Virgo/KAGRA S240910ci: Coverage and upper limits from MAXI/GSC observations
  100. LIGO/Virgo/KAGRA S240910ci: Updated Sky localization and EM Bright Classification

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