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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"

21000 results found.

  1. GRB 240929A: SAO RAS, Mondy, and CrAO optical observations
  2. GRB241001A: REM optical/NIR upper limits
  3. GRB 241002A: Swift/UVOT Upper Limits
  4. EP240930a: Liverpool Telescope observations
  5. GRB 241001A: GRANDMA and Kilonova-Catcher optical afterglow detection and upper limits
  6. GRB 241001A: Swift/UVOT Detection
  7. GRB 241001A: VLT/X-shooter redshift
  8. GRB 241002B: GOTO optical counterpart candidate
  9. EP trigger ID 01709064214: GOTO confirms detection as a flare star
  10. GRB 240929A: Liverpool Telescope prompt followup observations
  11. Fermi GRB 241002B: Global MASTER-Net observations report
  12. GRB 241001A: Swift-XRT observations
  13. GRB241001A: optical afterglow candidate
  14. GRB 241002A: 1.5m OSN optical upper limit
  15. GRB 241001A: Swift ToO observations
  16. Fermi-LAT Gamma-ray Observations of IceCube-240929A
  17. EP240930a: GOTO optical upper limits
  18. EP EP240930a: Global MASTER-Net observations report
  19. EP240930a: EP-WXT detection of a fast X-ray transient
  20. AMON NuEM 240926A: Swift XRT Follow-up
  21. GRB 240929A : Leavitt Observatory optical upper limit
  22. Fermi GRB 240930B: Global MASTER-Net observations report
  23. GRB 240825A: LBT optical observations
  24. Fermi GRB 240930A: Global MASTER-Net observations report
  25. Fermi trigger No 749339671: Global MASTER-Net observations report
  26. Fermi GRB 240929A: Global MASTER-Net observations report
  27. Integral GRB240929.83: Global MASTER-Net observations report
  28. EP trigger ID 01709059262: Lick/Kast spectroscopy with 3 m Shane telescope
  29. NuEm-240926A / IC240926A: BZQJ0955+4532 ~0.6m optical decay and rebrightening detection by MASTER
  30. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-240926A
  31. GRB 240529A: FRAM-ORM early optical afterglow observations reveal plateau and rebrightening
  32. EP240919a / GRB 240919A: SVOM/VT upper limit
  33. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  34. EP240918b and EP240918c: EP-FXT follow-up observations
  35. Insight-HXMT ToO observations of X-ray bursts from SGR 1E 1841-045 / Kes 73
  36. LIGO/Virgo S240919bn: GOTO optical upper limits
  37. LIGO/Virgo S240919bn: Swift XRT observations, 10 X-ray sources
  38. EP240919a: EP-FXT follow-up observation update
  39. EP240913a/GRB 240913C: 1.6m Mephisto observations
  40. EP240918a: SVOM/VT upper limit
  41. EP240919a / GRB 240919A: REM optical and NIR upper limits
  42. EP240918b and EP240918c: Optical upper limits with Kinder observations
  43. GRB 240414A: further radio observations with the VLA
  44. EP240919a: Optical upper limit with Kinder observations
  45. GRB 240919A / EP240919a: SVOM/GRM observation
  46. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  47. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  48. EP EP240919a: Global MASTER-Net observations report
  49. GRB 240910A: radio detection with the VLA
  50. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  51. EP240919a: NOT and Gemini optical observations
  52. EP240919a: GOTO optical upper limits
  53. EP240919a: JinShan optical upper limits
  54. EP240919a is likely a GRB event
  55. EP240919a: EP-WXT detection of a fast X-ray transient
  56. GRB 240918A and GRB 240918B : INTEGRAL SPI ACS LIGHT CURVE
  57. EP240918b and EP240918c: EP-WXT detection of two fast X-ray transients
  58. EP240918a: EP observation update
  59. GRB 240910A: further Swift observations and confirmation of afterglow
  60. Fermi GRB 240918A: Global MASTER-Net observations report
  61. EP EP240918a: Global MASTER-Net observations report
  62. EP240918a: JinShan optical upper limits
  63. EP240918a: Optical upper limits with Kinder observations
  64. EP240918a: an X-ray transient detected by Einstein Probe
  65. GRB 240825A: INTEGRAL SPI ACS LIGHT CURVE
  66. GRB 240825A: The nature of the afterglow motivates the search of the associated supernova
  67. GRB 240821A: radio observation with the VLA
  68. GRB 240916A: Swift-XRT afterglow detection
  69. GRB 240916A: Swift ToO observations
  70. LIGO/Virgo/KAGRA S240915b: NED Galaxies in the Localization Volume
  71. LIGO/Virgo S240915b: Swift XRT observations, 8 X-ray sources
  72. GRB 240916A: JinShan optical decay in one of the two GOTO candidates
  73. GRB 240916A: GOTO identification of two new optical sources within the GBM localisation region
  74. EP EP240913a: Global MASTER-Net observations report
  75. LIGO/Virgo/KAGRA S240915b: Coverage and upper limits from MAXI/GSC observations
  76. GRB 240916A INTEGRAL SPI ACS LIGHT CURVE
  77. EP240913a: VLT/HAWK-I near-infrared upper limits
  78. EP240913a / GRB 240913C INTEGRAL SPI ACS LIGHT CURVE
  79. GRB 240914A: Swift-XRT observations
  80. GRB 240910A: SVOM/VT optical observations
  81. GRB 240914A: Swift ToO observations
  82. EP240913a: NOT optical upper limits
  83. EP240913a: JinShan optical upper limits
  84. EP240913a: ESO-NTT optical observations
  85. GRB 240914A: ESO-NTT optical observations
  86. GRB 240905E: further NOT optical observations
  87. EP240913a: A GRB Event
  88. EP240913a: EP-WXT detection of a fast X-ray transient
  89. GRB 240911A: LCO optical observations
  90. GRB 240911A: JinShan optical upper limits on two Swift/XRT candidates
  91. GRB 240912A: Swift/UVOT Detection
  92. GRB 240911A: GOTO optical limits on Swift/XRT candidates
  93. Fermi trigger No 747920561: Global MASTER-Net observations report
  94. GRB 240911A: Swift-XRT observations
  95. Fermi GRB 240913A: Global MASTER-Net observations report
  96. GRB 240912A: J-band observations with WINTER
  97. Swift GRB 240912A: Global MASTER-Net observations report
  98. GRB 240912A: LCOGT detection and Legacy Surveys likely host galaxy
  99. GRB 240911A: Tiled Swift observations
  100. GRB 240912A : INTEGRAL SPI ACS LIGHT CURVE

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