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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"

27244 results found.

  1. GRB 241128C: SVOM/GRM observation
  2. GRB 241128B: SVOM/GRM observation
  3. GRB 241128A: Swift-BAT refined analysis
  4. GRB 241127A: Swift-BAT refined analysis
  5. EP241126a: NOT optical observations
  6. GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
  7. Swift-XRT observations of IceCube -241127A
  8. Swift GRB 241128A: Global MASTER-Net observations report
  9. EP241126a: SVOM/VT observations
  10. GRB 241128A: Swift-XRT refined Analysis
  11. GRB 241129A: Fermi GBM Final Real-time Localization
  12. GRB 241128A: LCO optical detection
  13. LIGO/Virgo S241127aj: GRANDMA/FRAM-CTA-N Observations
  14. Fermi trigger No 754492985: Global MASTER-Net observations report
  15. GRB 241128A: Swift-XRT afterglow detection
  16. GRB 241128A: Swift detection of a burst
  17. GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
  18. GRB 241127A: Swift/UVOT Detection
  19. GRB 241127A: Swift-XRT refined Analysis
  20. GRB 241127A: SVOM/GRM observation
  21. The EP-WXT trigger 01709125191 is not a real source
  22. GRB 241127A: LCOGT (40-cm) optical counterpart detection
  23. Swift GRB241127.91: Global MASTER-Net OT detection
  24. LIGO/Virgo/KAGRA S241125n: Update on Coincidence False Alarm Method
  25. IceCube Alert 241127.59: Global MASTER-Net observations report
  26. GRB 241127A: Swift detection of a burst with an optical counterpart
  27. Swift GRB241127.91: Global MASTER-Net observations report
  28. Swift GRB241127.91: Global MASTER-Net OT detection
  29. LIGO/Virgo/KAGRA S241125n: Swift-UVOT Upper Limits
  30. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations
  31. EP241126a: Optical Upper limits with Kinder observations
  32. SVOM/GRM observation of GRB 241126B or a short burst from magnetar
  33. GRB 241126A: SVOM/GRM observation
  34. EP trigger ID 01709122294: 1.6m Mephisto multi-band optical observations
  35. EP241126a: EP-FXT follow-up observation update
  36. EP241126a: GSP detects optical counterpart
  37. EP241126a: TRT optical counterpart detection
  38. EP241126a: EP detection of a fast X-ray transient
  39. LIGO/Virgo/KAGRA S241125n: SAGUARO follow-up observations with the MMT
  40. LIGO/Virgo/KAGRA S241126dm: Retraction of GW compact binary merger candidate
  41. GRB 241113B: EP-FXT afterglow detection
  42. LIGO/Virgo/KAGRA S241125n: Gaoyazi/GOT optical observations
  43. SVOM/GRM detection of a short burst from SGR 1830
  44. GECAM detection of a short burst from SGR 1830
  45. LIGO/VIRGO/KAGRA S241125n: GROWTH-India telescope optical observations
  46. LIGO/Virgo S241125n: Swift XRT observations, 5 X-ray sources
  47. EP241125a: Optical upper limit with Kinder observations
  48. EP241125a: EP detection of an X-ray transient
  49. LIGO/Virgo/KAGRA S241125n: Upper limits from Fermi-GBM Observations
  50. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  51. LIGO/Virgo/KAGRA S241125n: Kinder optical upper limit in the BAT error region
  52. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  53. LIGO/Virgo/KAGRA S241125n: No counterpart candidates in INTEGRAL SPI-ACS prompt observation, comparisong with Swift/BAT counterpart
  54. LIGO/Virgo/KAGRA S241125n: Updated Sky localization and Coincidence with External Event
  55. LIGO/Virgo/KAGRA S241125n: Swift/BAT-GUANO candidate counterpart
  56. GRB 241113B: SVOM/VT optical afterglow observations
  57. IPN triangulation of GRB 241117A
  58. GRB 241120A: CALET Gamma-Ray Burst Monitor detection
  59. EP trigger ID 01709065118: Keck/LRIS spectroscopic observations
  60. EP-WXT trigger 01709018832: Lick/Kast spectroscopy with the 3 m Shane telescope
  61. GRB 241120A: Mondy and AbAO optical observations
  62. EP241119a: Optical upper limits with Kinder observations
  63. EP trigger ID 01709122294: the X-ray transient is likely a stellar flare event
  64. EP241119a: GIT optical upper limits
  65. GRB 241120A: Fermi GBM Observation
  66. Integral GRB241120.25: Global MASTER-Net observations report
  67. EP241119a: Global MASTER-Net observations report
  68. EP241119a: EP detection of a fast X-ray transient
  69. GRB 241120A: Fermi GBM Final Real-time Localization
  70. GRB 241115A: CALET Gamma-Ray Burst Monitor detection
  71. GRB 241112B: Mephisto further optical observations
  72. GRB 241119A: Fermi GBM Final Real-time Localization
  73. GRB 241030A: J-band observations
  74. GRB 241117A: Swift/BAT-GUANO localization skymap of a burst
  75. LIGO/Virgo/KAGRA S241116cq: Upper limits from Swift/BAT-GUANO
  76. GRB 241115B: Fermi GBM Observation
  77. Fermi GRB 241118A: Global MASTER-Net observations report
  78. GRB 241118A: Fermi GBM Final Real-time Localization
  79. GRB 241117A: SVOM/GRM observation of a short burst with extended emission
  80. GRB 241117A: Fermi GBM Detection
  81. Fermi GRB 241117B: Global MASTER-Net observations report
  82. GRB 241117B: Fermi GBM Final Real-time Localization
  83. GRB 241115B: Swift/BAT-GUANO localization skymap of a long burst
  84. Fermi GRB 241117A: Global MASTER-Net observations report
  85. GRB 241117A: Fermi GBM Final Real-time Localization
  86. GRB 241115C: Fermi GBM Observation
  87. EP241115a/GRB 241115D: Optical upper limits with Kinder observations
  88. GRB 241115A: Mephisto upper limits
  89. GRB 241113B: Mephisto upper limits
  90. GRB 241115D / EP 241115a: SVOM/GRM observation
  91. The EP-WXT trigger 01709120856 is likely a flaring star
  92. GRB 241115A: Fermi GBM Observation
  93. GRB 241115A: LCOGT Optical Upper Limits
  94. GRB 241115C: Swift/BAT-GUANO localization skymap of a burst
  95. Fermi GRB 241115B: Global MASTER-Net observations report
  96. EP241115a: Global MASTER-Net observations report
  97. GRB 241115B: Fermi GBM Final Real-time Localization
  98. EP241115a: EP detection of a fast X-ray transient
  99. EP241113a: No Detection in Fermi-GBM Observations
  100. Swift GRB 241115A: Global MASTER-Net observations report

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