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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"

32767 results found.

  1. EP240919a / GRB 240919A: Mondy optical upper limit
  2. EP240913a/GRB 240913C: 1.6m Mephisto observations
  3. EP240918a: SVOM/VT upper limit
  4. Fermi GBM Sub-Threshold Detection of GRB240919A / EP240919a
  5. EP240919a / GRB 240919A: REM optical and NIR upper limits
  6. EP240919a / GRB 240919A: KAIT optical upper limit
  7. EP240918b and EP240918c: Optical upper limits with Kinder observations
  8. GRB 240414A: further radio observations with the VLA
  9. EP240919a: Optical upper limit with Kinder observations
  10. GRB 240919A / EP240919a: SVOM/GRM observation
  11. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  12. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  13. LIGO/Virgo/KAGRA S240920dw: Identification of a GW compact binary merger candidate
  14. EP EP240919a: Global MASTER-Net observations report
  15. GRB 240910A: radio detection with the VLA
  16. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  17. EP240919a: NOT and Gemini optical observations
  18. EP240919a: GOTO optical upper limits
  19. EP240919a: JinShan optical upper limits
  20. EP240919a is likely a GRB event (duplicate submission of 37563)
  21. EP240919a is likely a GRB event
  22. LIGO/Virgo/KAGRA S240920bz: Identification of a GW compact binary merger candidate
  23. GRB 240918A and GRB 240918B : INTEGRAL SPI ACS LIGHT CURVE
  24. LIGO/Virgo/KAGRA S240919bn: Updated Sky localization
  25. GRB 240918B: Fermi GBM Detection
  26. LIGO/Virgo/KAGRA S240917cb: Updated Sky localization and EM Bright Classification
  27. LIGO/Virgo/KAGRA S240916ar: Updated Sky localization and EM Bright Classification
  28. EP240918a: EP observation update
  29. GRB 240910A: further Swift observations and confirmation of afterglow
  30. LIGO/Virgo/KAGRA S240919bn: Identification of a GW compact binary merger candidate
  31. EP240918a: Swift-XRT observation
  32. Fermi GRB 240918A: Global MASTER-Net observations report
  33. EP EP240918a: Global MASTER-Net observations report
  34. EP240918a: JinShan optical upper limits
  35. EP240918a: YAHPT Optical Upper Limit
  36. EP240918a: Optical upper limits with Kinder observations
  37. EP240918a: GMG Optical Upper Limit
  38. GRB 240916A: GRBAlpha detection
  39. GRB 240914B: GRBAlpha detection
  40. GRB 240916A: NOT optical observation
  41. GRB 240912A: Swift-BAT refined analysis
  42. IPN triangulation of GRB 240913C / EP 240913a
  43. GRB 240825A: INTEGRAL SPI ACS LIGHT CURVE
  44. GRB 240825A: The nature of the afterglow motivates the search of the associated supernova
  45. GRB 240916A: Fermi GBM Observation
  46. LIGO/Virgo/KAGRA S240917cb: Identification of a GW compact binary merger candidate
  47. GRB 240821A: radio observation with the VLA
  48. GRB 240916A (AT 2024vlp / GOTO24fzn): VLT/X-shooter redshift
  49. GRB 240916A: Swift-XRT afterglow detection
  50. LIGO/Virgo/KAGRA S240916ar: Identification of a GW compact binary merger candidate
  51. GRB 240916A: Swift ToO observations
  52. GRB 240916A: JinShan optical decay in one of the two GOTO candidates
  53. GRB 240916A: GOTO identification of two new optical sources within the GBM localisation region
  54. EP EP240913a: Global MASTER-Net observations report
  55. LIGO/Virgo/KAGRA S240915b: Coverage and upper limits from MAXI/GSC observations
  56. GRB 240916A INTEGRAL SPI ACS LIGHT CURVE
  57. LIGO/Virgo/KAGRA S240915bd: Updated Sky localization
  58. EP240913a: VLT/HAWK-I near-infrared upper limits
  59. LIGO/Virgo/KAGRA S240915bd: Identification of a GW compact binary merger candidate
  60. LIGO/Virgo/KAGRA S240915b: Updated Sky localization and EM Bright Classification
  61. LIGO/Virgo/KAGRA S240915b: Identification of a GW compact binary merger candidate
  62. EP240913a/GRB 240913C: KAIT optical upper limit
  63. EP240913a / GRB 240913C INTEGRAL SPI ACS LIGHT CURVE
  64. GRB 240913C: Fermi GBM detection
  65. GRB 240913C: Joint location by ETJASMIN
  66. GRB 240914B: AstroSat CZTI detection
  67. EP240913A / GRB 240913C: AstroSat CZTI detection
  68. GRB 240914A: SVOM/GRM observation
  69. GRB 240910A: SVOM/VT optical observations
  70. GRB 240914A: Swift ToO observations
  71. EP240913a: NOT optical upper limits
  72. EP240913a: JinShan optical upper limits
  73. EP240913a: ESO-NTT optical observations
  74. GRB 240914A: ESO-NTT optical observations
  75. EP240913a: Swift/XRT detection of an X-ray source within the EP/WXT error circle
  76. GRB 240905E: further NOT optical observations
  77. EP240913a: A GRB Event
  78. GRB 240911A: LCO optical observations
  79. GRB 240911A: JinShan optical upper limits on two Swift/XRT candidates
  80. Fermi Gamma-ray Burst Monitor trigger 747837485/240912526 is not a GRB
  81. GRB 240912A: Swift/UVOT Detection
  82. GRB 240911A: GOTO optical limits on Swift/XRT candidates
  83. GRB 240912A: SVOM/GRM observation
  84. Fermi GRB 240913A: Global MASTER-Net observations report
  85. GRB 240912A: J-band observations with WINTER
  86. GRB 240912A: Fermi GBM Observation
  87. Swift GRB 240912A: Global MASTER-Net observations report
  88. GRB 240912A: LCOGT detection and Legacy Surveys likely host galaxy
  89. GRB 240911A: Tiled Swift observations
  90. GRB 240912A : INTEGRAL SPI ACS LIGHT CURVE
  91. GRB 240912A: NOT optical spectroscopy
  92. GRB 240912A: Redshift from OSIRIS+/GTC
  93. Fast X-ray Transient EP240801a: GMRT radio observations
  94. GRB 240910A: Redshift from OSIRIS+/GTC
  95. GRB 240910A: Fermi GBM Observation
  96. GRB 240910A: NOT optical observations
  97. GRB 240910A: Swift-XRT detection of GOTO24fvl/AT2024vfp
  98. GRB 240910A: JinShan optical observations
  99. GRB 240910A: GOTO candidate optical counterpart
  100. EP240908a: Optical afterglow confirmation

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