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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"

24515 results found.

  1. Fermi trigger No 752365806: Global MASTER-Net observations report
  2. LIGO/Virgo/KAGRA S241102cy: Updated Sky localization
  3. LIGO/Virgo/KAGRA S241102br: Updated Sky localization
  4. EP241101a: Possible detection of an optical counterpart with FTW
  5. EP241101a: Optical upper limits with Kinder observations
  6. LIGO/Virgo/KAGRA S241102br: MASTER observations and OT detection
  7. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  8. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  9. EP241103a: Global MASTER-Net observations report
  10. GRB 241030A: Rapid release of TESS data.
  11. EP241101a: Global MASTER-Net observations report
  12. GRB 241029A: GRBAlpha detection
  13. LIGO/Virgo/KAGRA S241101ee: Updated Sky localization
  14. S241102cy: Identification of a GW compact binary merger candidate
  15. LIGO/Virgo/KAGRA S241102br: NED Galaxies in the Localization Volume
  16. LIGO/Virgo/KAGRA S241102br: Identification of a GW compact binary merger candidate
  17. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  18. EP241101a: EP-WXT detection of a fast X-ray transient
  19. Swift GRB 241101A: Global MASTER-Net observations report
  20. GRB 241101A: FRAM-ORM optical limit
  21. LIGO/Virgo/KAGRA S241101ee: Identification of a GW compact binary merger candidate
  22. EP241021a: Upper limit from Konus-Wind observations
  23. GRB 241101A: Swift-BAT refined analysis
  24. GRB 241030A: Optical Observations via Virtual Telescope Project
  25. GRB 241101A: Swift detection of a burst
  26. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  27. Fermi trigger No 752083996: Global MASTER-Net observations report
  28. GRB 241030A: Fermi GBM Observation
  29. EP241021a: AMI-LA radio detection
  30. GRB 241030B: LCOGT Optical Upper Limits
  31. GRB 241030B: Swift-BAT refined analysis
  32. GRB 241030A: Swift-BAT refined analysis
  33. EP EP241030a: Global MASTER-Net observations report
  34. Fermi trigger No 752006065: Global MASTER-Net observations report
  35. Swift GRB241030.77: Global MASTER-Net observations report
  36. GRB 241030B: SVOM/GRM observation
  37. GRB 241030B : MITSuME Akeno optical upper limits
  38. GRB 241030B: SVOM/VT optical afterglow observations
  39. GRB241030B: Fermi GBM Observation
  40. GRB 241029A: SVOM/VT optical afterglow observations
  41. GRB 241030B: optical observations from the INAF Asiago Observatory
  42. GRB 241030A: Swift-XRT refined Analysis
  43. GRB 241030B: SVOM/ECLAIRs detection of a burst
  44. Konus-Wind detection of GRB 241030A
  45. GRB 241030B: Swift detection of a burst
  46. GRB 241030B: Fermi GBM Final Real-time Localization
  47. GRB 241030A: Fermi-LAT detection
  48. Fermi GRB 241030A: Global MASTER-Net observations report
  49. Swift GRB 241030A: Global MASTER-Net observations report
  50. GRB 241030A: SVOM/GRM observation
  51. GRB 241026A: Swift-BAT refined analysis
  52. GRB 241030A: SVOM/C-GFT optical observations
  53. GRB 241026A: LBT optical observations
  54. EP241021a: Optical rebrightening observations with Mephisto
  55. EP241026b: EP-FXT follow-up observation
  56. GRB 241030A: Multiband optical detection with Mephisto
  57. GRB 241030A : MITSuME Akeno optical afterglow detection
  58. GRB 241030A: Fermi GBM Final Real-time Localization
  59. GRB 241029A: Fermi GBM Observation
  60. GRB 241029A: MASTER early optical counterpart detection
  61. GRB 241029A: Mephisto observations
  62. EP 241026b: LBT possible optical counterpart (brightening source)
  63. GRB 241029A: TRT optical afterglow candidate detection
  64. GRB 241029A: SVOM/GRM observation
  65. GRB 241029A : Detection and localization of a bright long GRB by SVOM/ECLAIRs
  66. Fermi trigger No 751861204: Global MASTER-Net observations report
  67. GRB 241029A: Fermi GBM Final Real-time Localization
  68. GRB 241026A: the 100th GRB detected by GRBAlpha
  69. Konus-Wind detection of GRB 241025A
  70. GRB 241026A: GECAM detection
  71. GRB 241026A: SVOM/GRM observation
  72. GRB 241026A Fermi GBM Analysis
  73. EP241026a (GRB 241026A): EP on-board trigger and follow-up observation
  74. EP EP241026b: Global MASTER-Net observations report
  75. GRB 241026A: KAIT optical observations
  76. Fermi trigger No 751616906: Global MASTER-Net observations report
  77. Fermi GRB 241026A: Global MASTER-Net observations report
  78. GRB 241026A: Swift detection of a burst
  79. Swift GRB241026.95: Global MASTER-Net observations report
  80. GRB 241026A: Fermi GBM Final Real-time Localization
  81. GRB241025A: 1.3m DFOT optical afterglow detection
  82. EP241021a: optical follow-up observations with Xinglong Observatory
  83. GRB 241025C: Fermi GBM Detection
  84. GRB 241025A: Fermi GBM Observation
  85. IPN triangulation of GRB 241022A (short/hard)
  86. LIGO/Virgo/KAGRA S241009l: Upper limits from Swift/BAT-GUANO
  87. GRB 241025C: Fermi GBM Final Localization
  88. GRB 241025B: Fermi GBM Final Localization
  89. Fermi trigger No 751563375: Global MASTER-Net observations report
  90. Fermi trigger No 751554401: Global MASTER-Net observations report
  91. EP241021a: optical follow-up observations with the Liverpool Telescope
  92. Fermi GRB 241025A: Global MASTER-Net observations report
  93. Swift GRB 241025A: Global MASTER-Net observations report
  94. GRB 241001A: JWST spectroscopic identification of a supernova counterpart
  95. GRB 241025A: NOT spectroscopic redshift of z = 4.20
  96. EP241025a (GRB 241025A): EP on-board trigger and autonomous follow-up observation
  97. GRB 241025A: SVOM/GRM observation
  98. GRB 241025A: TRT optical afterglow observation
  99. Fermi GRB 241024B: Global MASTER-Net observations report
  100. GRB 241025A: Fermi GBM Final Real-time Localization

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