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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"

21056 results found.

  1. EP240801a: TRT optical counterpart detection
  2. EP240801a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  3. Fermi GRB 240801A: Global MASTER-Net observations report
  4. Fermi trigger No 744128417: Global MASTER-Net observations report
  5. Fermi trigger No 744083370: Global MASTER-Net observations report
  6. GRB 240730A: Osservatorio Astronomico Nastro Verde upper limit
  7. Fermi GRB 240730B: Global MASTER-Net observations report
  8. Swift GRB 240730A: Global MASTER-Net observations report
  9. GRB 240715A: Swift-XRT afterglow detection
  10. GRB 240730A: Swift/UVOT Upper Limits
  11. Fermi trigger No 743953682: Global MASTER-Net observations report
  12. LIGO/Virgo/KAGRA S240615dg: GRAWITA wide-field optical observations
  13. GRB 240727A: observations of optical counterpart.
  14. GRB 240727B: Swift-XRT observations
  15. Fermi GRB 240727A: Global MASTER-Net observations report
  16. GRB 240727A: Swift/UVOT detection
  17. Fermi trigger No 743868421: Global MASTER-Net observations report
  18. GRB 240727A: Osservatorio Astronomico Nastro Verde upper limit
  19. GRB 240727A: JinShan optical upper limits
  20. GRB 240727A Bassano Bresciano Observatory upper limit
  21. Fermi GRB 240726A: Global MASTER-Net observations report
  22. Swift GRB240727.16: Global MASTER-Net observations report
  23. GRB 240727B: Swift ToO observations
  24. GRB 240727B: Swift/BAT-GUANO arcminute localization of a long burst
  25. GRB240727A: Skynet Optical Afterglow Observations
  26. GRB 240727A: TRT optical afterglow detection
  27. GRB 240727A: KAIT Optical Afterglow Candidate
  28. Fermi-LAT gamma-ray observations of IceCube-240725A
  29. IceCube Alert 240725.22: Global MASTER-Net observations report
  30. Swift GRB240725.11: Global MASTER-Net observations report
  31. IceCube-240721A: Two candidates from the Zwicky Transient Facility
  32. Fermi trigger No 743418632: Global MASTER-Net observations report
  33. Fermi trigger No 743315411: Global MASTER-Net observations report
  34. Fermi trigger No 743345551: Global MASTER-Net observations report
  35. Fermi-LAT gamma-ray observations of IceCube-240721A
  36. Fermi trigger No 743219692: Global MASTER-Net observations report
  37. IceCube Alert 240721.68: Global MASTER-Net observations report
  38. Fermi GRB 240720A: Global MASTER-Net observations report
  39. Swift GRB240720.02: Global MASTER-Net observations report
  40. Fermi GRB 240718A: Global MASTER-Net observations report
  41. LAT GRB240718.27: Global MASTER-Net observations report
  42. IceCube-Cascade 240714A: TRT optical observations on the EP/FXT positions
  43. Fermi-LAT gamma-ray observations of IceCube-cascade-240714A
  44. GRB 240715A: Swift/UVOT observations of the XRT sources.
  45. GRB 240715A: Swift-XRT observations
  46. GRB240713A: Swift/UVOT Upper LImits
  47. EP240708a: X-ray follow-up observations with Swift/XRT
  48. GRB 240713A: Swift-XRT observations
  49. GRB 240713A: LAST optical upper limit
  50. GRB 240715A: Swift ToO observations
  51. Fermi GRB 240715A: Global MASTER-Net observations report
  52. GRB 240712A ATCA radio observations
  53. GRB240715A: GRANDMA Optical Upper Limits
  54. GRB 240712A: Swift/UVOT Upper Limits
  55. EP-WXT flaring star and the optical flaring activity during its decay phase
  56. JinShan confirmation of the EP-WXT source triggered on July 14th due to a flaring star
  57. The EP-WXT source triggered on July 14th is likely a flaring star
  58. GRB 240713A: Tiled Swift observations
  59. GRB 240713A: J-band upper limit from WINTER
  60. GRB 240713A: JinShan optical upper limits
  61. GRB 240713A: OHP/T120 optical upper limit
  62. GRB240713A: Optical upper limit with Kinder observations
  63. GRB240713A: TAROT and GRANDMA Observations of SVOM/ECLAIRs GRB240713A
  64. EP240708a: GSP optical upper limit
  65. LIGO/Virgo/KAGRA S240711cm: Coverage and upper limits from MAXI/GSC observations
  66. Fermi trigger No 742405878: Global MASTER-Net observations report
  67. Fermi trigger No 742317942: Global MASTER-Net observations report
  68. Fermi GRB 240710A: Global MASTER-Net observations report
  69. EP240708a: NOT optical observations
  70. EP240708a: X-ray follow-up observations with EP/FXT and Swift/XRT
  71. EP240708a: Optical upper limits with Kinder observations
  72. EP240708a: EP-WXT detection of a fast X-ray transient
  73. LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources
  74. EP240703b: GSP optical upper limit
  75. EP240703b: TRT optical upper limits
  76. EP240703a: TRT further optical observation
  77. EP240702a: TRT optical upper limits
  78. EP240703a and EP240703b: Swift/XRT upper limits
  79. EP240703a: BTA observations
  80. EP240703c: Kinder optical follow-up and Swift XRT observations
  81. EP240703a: Liverpool Telescope optical follow-up observations
  82. EP240703a: Kinder optical follow-up observations
  83. EP240703c: EP-WXT detection of an X-ray transient
  84. The first three GRBs detected by SVOM: X-ray Upper Limits from EP-WXT
  85. EP240703b: EP-WXT detection of a fast X-ray transient
  86. EP240703a: EP-WXT detection of a fast X-ray transient
  87. EP240702a: GSP optical upper limit
  88. The first three GRBs detected by SVOM: GRB 240627B, GRB 240629A and GRB 240702A
  89. Fermi GRB 240702A: Global MASTER-Net observations report
  90. EP240702a: EP-WXT detection of a fast X-ray transient
  91. Fermi trigger No 741448122: Global MASTER-Net observations report
  92. LIGO/Virgo/KAGRA S240629by: Upper limits from Fermi-GBM Observations
  93. LIGO/Virgo/KAGRA S240629by: Coverage and upper limits from MAXI/GSC observations
  94. Fermi trigger No 741356809: Global MASTER-Net observations report
  95. Fermi GRB 240629A: Global MASTER-Net observations report
  96. Fermi trigger No 741296200: Global MASTER-Net observations report
  97. Fermi trigger No 741251380: Global MASTER-Net observations report
  98. GRB 240615A: SAI CMO J- band observations
  99. Fermi trigger No 741211696: Global MASTER-Net observations report
  100. EP240626a: Montarrenti Observatory optical upper limit

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