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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"

20997 results found.

  1. EP240930a: Liverpool Telescope observations
  2. GRB 241001A: GRANDMA and Kilonova-Catcher optical afterglow detection and upper limits
  3. GRB 241001A: Swift/UVOT Detection
  4. GRB 241001A: VLT/X-shooter redshift
  5. GRB 241002B: GOTO optical counterpart candidate
  6. EP trigger ID 01709064214: GOTO confirms detection as a flare star
  7. GRB 240929A: Liverpool Telescope prompt followup observations
  8. Fermi GRB 241002B: Global MASTER-Net observations report
  9. GRB 241001A: Swift-XRT observations
  10. GRB241001A: optical afterglow candidate
  11. GRB 241002A: 1.5m OSN optical upper limit
  12. GRB 241001A: Swift ToO observations
  13. Fermi-LAT Gamma-ray Observations of IceCube-240929A
  14. EP240930a: GOTO optical upper limits
  15. EP EP240930a: Global MASTER-Net observations report
  16. EP240930a: EP-WXT detection of a fast X-ray transient
  17. AMON NuEM 240926A: Swift XRT Follow-up
  18. GRB 240929A : Leavitt Observatory optical upper limit
  19. Fermi GRB 240930B: Global MASTER-Net observations report
  20. GRB 240825A: LBT optical observations
  21. Fermi GRB 240930A: Global MASTER-Net observations report
  22. Fermi trigger No 749339671: Global MASTER-Net observations report
  23. Fermi GRB 240929A: Global MASTER-Net observations report
  24. Integral GRB240929.83: Global MASTER-Net observations report
  25. EP trigger ID 01709059262: Lick/Kast spectroscopy with 3 m Shane telescope
  26. NuEm-240926A / IC240926A: BZQJ0955+4532 ~0.6m optical decay and rebrightening detection by MASTER
  27. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-240926A
  28. GRB 240529A: FRAM-ORM early optical afterglow observations reveal plateau and rebrightening
  29. EP240919a / GRB 240919A: SVOM/VT upper limit
  30. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  31. EP240918b and EP240918c: EP-FXT follow-up observations
  32. Insight-HXMT ToO observations of X-ray bursts from SGR 1E 1841-045 / Kes 73
  33. LIGO/Virgo S240919bn: GOTO optical upper limits
  34. LIGO/Virgo S240919bn: Swift XRT observations, 10 X-ray sources
  35. EP240919a: EP-FXT follow-up observation update
  36. EP240913a/GRB 240913C: 1.6m Mephisto observations
  37. EP240918a: SVOM/VT upper limit
  38. EP240919a / GRB 240919A: REM optical and NIR upper limits
  39. EP240918b and EP240918c: Optical upper limits with Kinder observations
  40. GRB 240414A: further radio observations with the VLA
  41. EP240919a: Optical upper limit with Kinder observations
  42. GRB 240919A / EP240919a: SVOM/GRM observation
  43. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  44. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  45. EP EP240919a: Global MASTER-Net observations report
  46. GRB 240910A: radio detection with the VLA
  47. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  48. EP240919a: NOT and Gemini optical observations
  49. EP240919a: GOTO optical upper limits
  50. EP240919a: JinShan optical upper limits
  51. EP240919a is likely a GRB event
  52. EP240919a: EP-WXT detection of a fast X-ray transient
  53. GRB 240918A and GRB 240918B : INTEGRAL SPI ACS LIGHT CURVE
  54. EP240918b and EP240918c: EP-WXT detection of two fast X-ray transients
  55. EP240918a: EP observation update
  56. GRB 240910A: further Swift observations and confirmation of afterglow
  57. Fermi GRB 240918A: Global MASTER-Net observations report
  58. EP EP240918a: Global MASTER-Net observations report
  59. EP240918a: JinShan optical upper limits
  60. EP240918a: Optical upper limits with Kinder observations
  61. EP240918a: an X-ray transient detected by Einstein Probe
  62. GRB 240825A: INTEGRAL SPI ACS LIGHT CURVE
  63. GRB 240825A: The nature of the afterglow motivates the search of the associated supernova
  64. GRB 240821A: radio observation with the VLA
  65. GRB 240916A: Swift-XRT afterglow detection
  66. GRB 240916A: Swift ToO observations
  67. LIGO/Virgo/KAGRA S240915b: NED Galaxies in the Localization Volume
  68. LIGO/Virgo S240915b: Swift XRT observations, 8 X-ray sources
  69. GRB 240916A: JinShan optical decay in one of the two GOTO candidates
  70. GRB 240916A: GOTO identification of two new optical sources within the GBM localisation region
  71. EP EP240913a: Global MASTER-Net observations report
  72. LIGO/Virgo/KAGRA S240915b: Coverage and upper limits from MAXI/GSC observations
  73. GRB 240916A INTEGRAL SPI ACS LIGHT CURVE
  74. EP240913a: VLT/HAWK-I near-infrared upper limits
  75. EP240913a / GRB 240913C INTEGRAL SPI ACS LIGHT CURVE
  76. GRB 240914A: Swift-XRT observations
  77. GRB 240910A: SVOM/VT optical observations
  78. GRB 240914A: Swift ToO observations
  79. EP240913a: NOT optical upper limits
  80. EP240913a: JinShan optical upper limits
  81. EP240913a: ESO-NTT optical observations
  82. GRB 240914A: ESO-NTT optical observations
  83. GRB 240905E: further NOT optical observations
  84. EP240913a: A GRB Event
  85. EP240913a: EP-WXT detection of a fast X-ray transient
  86. GRB 240911A: LCO optical observations
  87. GRB 240911A: JinShan optical upper limits on two Swift/XRT candidates
  88. GRB 240912A: Swift/UVOT Detection
  89. GRB 240911A: GOTO optical limits on Swift/XRT candidates
  90. Fermi trigger No 747920561: Global MASTER-Net observations report
  91. GRB 240911A: Swift-XRT observations
  92. Fermi GRB 240913A: Global MASTER-Net observations report
  93. GRB 240912A: J-band observations with WINTER
  94. Swift GRB 240912A: Global MASTER-Net observations report
  95. GRB 240912A: LCOGT detection and Legacy Surveys likely host galaxy
  96. GRB 240911A: Tiled Swift observations
  97. GRB 240912A : INTEGRAL SPI ACS LIGHT CURVE
  98. GRB 240912A: Redshift from OSIRIS+/GTC
  99. Fast X-ray Transient EP240801a: GMRT radio observations
  100. GRB 240910A: NOT optical observations

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