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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"

32701 results found.

  1. Fermi-LAT gamma-ray observations of IceCube-240721A
  2. Fermi Gamma-ray Burst Monitor trigger 743243582/240721356 (GRB 240721A) is not a GRB
  3. GRB 240720B: SVOM/GRM observation
  4. Fermi GRB 240720A: Global MASTER-Net observations report
  5. GRB 240720A: AstroSat CZTI detection
  6. GRB 240720A: Fermi GBM observation
  7. Konus-Wind detection of GRB 240718A
  8. GRB 240713A: SVOM/GRM observation
  9. Fermi GRB 240718A: Global MASTER-Net observations report
  10. GRB 240718A: Fermi GBM Observation
  11. IceCube-Cascade 240714A: TRT optical observations on the EP/FXT positions
  12. GRB 240718A: Fermi-LAT Detection
  13. GRB 240718A: SVOM/GRM observation
  14. GRB 240712A: Swift-BAT refined analysis
  15. GRB 240716A: GECAM-B detection of a long burst
  16. GRB 240715A: Swift/UVOT observations of the XRT sources.
  17. GRB240713A: Swift/UVOT Upper LImits
  18. EP240708a: X-ray follow-up observations with Swift/XRT
  19. GRB 240715A: GECAM-C detection of a short burst
  20. Konus-Wind detection of GRB 240715A
  21. LIGO/Virgo/KAGRA S240716b: Updated Sky localization
  22. GRB 240713A: Swift-XRT observations
  23. GRB 240715A: TRT optical upper limit on one Swift/XRT candidate
  24. SVOM/GRM In-Flight Trigger of GRB 240715A
  25. GRB 240713A: LAST optical upper limit
  26. LIGO/Virgo/KAGRA S240716b: Identification of a GW compact binary merger candidate
  27. GRB 240715A: Swift ToO observations
  28. Fermi GRB 240715A: Global MASTER-Net observations report
  29. GRB 240713A: optical upper limits from the INAF Asiago Observatory
  30. GRB 240715A: Fermi GBM Observation
  31. GRB 240712A ATCA radio observations
  32. GRB240715A: GRANDMA Optical Upper Limits
  33. IPN triangulation of GRB 240715A (short)
  34. GRB 240712A: Swift/UVOT Upper Limits
  35. EP-WXT flaring star and the optical flaring activity during its decay phase
  36. JinShan confirmation of the EP-WXT source triggered on July 14th due to a flaring star
  37. GRB 240713A: Tiled Swift observations
  38. GRB 240713A: J-band upper limit from WINTER
  39. GRB 240713A: NOT optical upper limits on three EP/FXT candidates
  40. GRB 240713A: JinShan optical upper limits
  41. GRB 240713A: OHP/T120 optical upper limit
  42. GRB240713A: X-ray follow-up observation with EP-FXT (duplicate submission of GCN 36859)
  43. GRB240713A: X-ray follow-up observation with EP-FXT
  44. GRB240713A: Optical upper limit with Kinder observations
  45. Fermi Sub-threshold Observation of GRB240713A
  46. EP240708a: GSP optical upper limit
  47. LIGO/Virgo/KAGRA S240627by: Updated Sky localization and EM Bright Classification
  48. EP240708a: KAIT optical upper limit
  49. Fermi GRB 240710A: Global MASTER-Net observations report
  50. EP240708a: NOT optical observations
  51. EP240708a: SVOM/C-GFT optical upper limit
  52. EP240708a: X-ray follow-up observations with EP/FXT and Swift/XRT
  53. EP240708a: Optical upper limits with Kinder observations
  54. LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources
  55. EP240703b: GSP optical upper limit
  56. EP240703b: TRT optical upper limits
  57. EP240703a: TRT further optical observation
  58. EP240702a: TRT optical upper limits
  59. Konus-Wind detection of GRB 240627A
  60. LIGO/Virgo/KAGRA S240705at: Updated Sky localization
  61. EP240703a and EP240703b: Swift/XRT upper limits
  62. LIGO/Virgo/KAGRA S240705at: Identification of a GW compact binary merger candidate
  63. EP240703a: KAIT optical upper limit
  64. EP240703a: BTA observations
  65. EP240703c: Kinder optical follow-up and Swift XRT observations
  66. EP240703a: Liverpool Telescope optical follow-up observations
  67. EP240703a/GRB 240703A: TRT optical candidate likely not real
  68. EP240703a: Kinder optical follow-up observations
  69. LIGO/Virgo/KAGRA S240703ad: Updated Sky localization
  70. LIGO/Virgo/KAGRA S240703ad: Identification of a GW compact binary merger candidate
  71. EP240703a/GRB 240703A: TRT and JinShan decaying optical afterglow candidate
  72. IPN triangulation of GRB 240627A
  73. GRB 240619A: Host galaxy redshift from VLT/X-shooter
  74. LIGO/Virgo/KAGRA S240422ed: Updated significance estimate
  75. The first three GRBs detected by SVOM: X-ray Upper Limits from EP-WXT
  76. Konus-Wind detection of GRB 240703A (a counterpart of EP240703a)
  77. EP240702a: Swift/XRT upper limit
  78. EP240702a: GSP optical upper limit
  79. Fermi GRB 240702A: Global MASTER-Net observations report
  80. GRB 240627A: CALET Gamma-Ray Burst Monitor detection
  81. LIGO/Virgo/KAGRA S240630t: Updated Sky localization
  82. LIGO/Virgo/KAGRA S240629by: Updated Sky localization
  83. LIGO/Virgo/KAGRA S240630t: Identification of a GW compact binary merger candidate
  84. LIGO/Virgo/KAGRA S240629by: Upper limits from Fermi-GBM Observations
  85. LIGO/Virgo/KAGRA S240629by: Coverage and upper limits from MAXI/GSC observations
  86. Fermi GRB 240629A: Global MASTER-Net observations report
  87. Fermi Gamma-ray Burst Monitor trigger 741288821/240628732 is not a GRB
  88. LIGO/Virgo/KAGRA S240629by: Identification of a GW compact binary merger candidate
  89. IPN triangulation of GRB 240619C
  90. GRB 240627A: NuSTAR Detection of the long GRB
  91. GRB 240615A: SAI CMO J- band observations
  92. EP240626a: Montarrenti Observatory optical upper limit
  93. LIGO/Virgo/KAGRA S240627by: Identification of a GW compact binary merger candidate
  94. EP240625a: GRANDMA Optical Upper Limits
  95. EP240626a: EP-FXT detection of the X-ray emission
  96. GRB 240624A: Swift-BAT refined analysis
  97. Konus-Wind detection of GRB 240619A
  98. Fermi GRB 240625B: Global MASTER-Net observations report
  99. GRB 240624B: CALET Gamma-Ray Burst Monitor detection
  100. GRB 240625A: Fermi GBM Observation

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