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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"

27234 results found.

  1. GRB 241129A: Fermi GBM Final Real-time Localization
  2. GRB 241128A: LCO optical detection
  3. LIGO/Virgo S241127aj: GRANDMA/FRAM-CTA-N Observations
  4. Fermi trigger No 754492985: Global MASTER-Net observations report
  5. GRB 241128A: Swift-XRT afterglow detection
  6. GRB 241128A: Swift detection of a burst
  7. GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
  8. GRB 241127A: Swift/UVOT Detection
  9. GRB 241127A: Swift-XRT refined Analysis
  10. GRB 241127A: SVOM/GRM observation
  11. The EP-WXT trigger 01709125191 is not a real source
  12. GRB 241127A: LCOGT (40-cm) optical counterpart detection
  13. Swift GRB241127.91: Global MASTER-Net OT detection
  14. LIGO/Virgo/KAGRA S241125n: Update on Coincidence False Alarm Method
  15. IceCube Alert 241127.59: Global MASTER-Net observations report
  16. GRB 241127A: Swift detection of a burst with an optical counterpart
  17. Swift GRB241127.91: Global MASTER-Net observations report
  18. Swift GRB241127.91: Global MASTER-Net OT detection
  19. LIGO/Virgo/KAGRA S241125n: Swift-UVOT Upper Limits
  20. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations
  21. EP241126a: Optical Upper limits with Kinder observations
  22. SVOM/GRM observation of GRB 241126B or a short burst from magnetar
  23. GRB 241126A: SVOM/GRM observation
  24. EP trigger ID 01709122294: 1.6m Mephisto multi-band optical observations
  25. EP241126a: EP-FXT follow-up observation update
  26. EP241126a: GSP detects optical counterpart
  27. EP241126a: TRT optical counterpart detection
  28. EP241126a: EP detection of a fast X-ray transient
  29. LIGO/Virgo/KAGRA S241125n: SAGUARO follow-up observations with the MMT
  30. LIGO/Virgo/KAGRA S241126dm: Retraction of GW compact binary merger candidate
  31. GRB 241113B: EP-FXT afterglow detection
  32. LIGO/Virgo/KAGRA S241125n: Gaoyazi/GOT optical observations
  33. SVOM/GRM detection of a short burst from SGR 1830
  34. GECAM detection of a short burst from SGR 1830
  35. LIGO/VIRGO/KAGRA S241125n: GROWTH-India telescope optical observations
  36. LIGO/Virgo S241125n: Swift XRT observations, 5 X-ray sources
  37. EP241125a: Optical upper limit with Kinder observations
  38. EP241125a: EP detection of an X-ray transient
  39. LIGO/Virgo/KAGRA S241125n: Upper limits from Fermi-GBM Observations
  40. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  41. LIGO/Virgo/KAGRA S241125n: Kinder optical upper limit in the BAT error region
  42. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  43. LIGO/Virgo/KAGRA S241125n: No counterpart candidates in INTEGRAL SPI-ACS prompt observation, comparisong with Swift/BAT counterpart
  44. LIGO/Virgo/KAGRA S241125n: Updated Sky localization and Coincidence with External Event
  45. LIGO/Virgo/KAGRA S241125n: Swift/BAT-GUANO candidate counterpart
  46. GRB 241113B: SVOM/VT optical afterglow observations
  47. IPN triangulation of GRB 241117A
  48. GRB 241120A: CALET Gamma-Ray Burst Monitor detection
  49. EP trigger ID 01709065118: Keck/LRIS spectroscopic observations
  50. EP-WXT trigger 01709018832: Lick/Kast spectroscopy with the 3 m Shane telescope
  51. GRB 241120A: Mondy and AbAO optical observations
  52. EP241119a: Optical upper limits with Kinder observations
  53. EP trigger ID 01709122294: the X-ray transient is likely a stellar flare event
  54. EP241119a: GIT optical upper limits
  55. GRB 241120A: Fermi GBM Observation
  56. Integral GRB241120.25: Global MASTER-Net observations report
  57. EP241119a: Global MASTER-Net observations report
  58. EP241119a: EP detection of a fast X-ray transient
  59. GRB 241120A: Fermi GBM Final Real-time Localization
  60. GRB 241115A: CALET Gamma-Ray Burst Monitor detection
  61. GRB 241112B: Mephisto further optical observations
  62. GRB 241119A: Fermi GBM Final Real-time Localization
  63. GRB 241030A: J-band observations
  64. GRB 241117A: Swift/BAT-GUANO localization skymap of a burst
  65. LIGO/Virgo/KAGRA S241116cq: Upper limits from Swift/BAT-GUANO
  66. GRB 241115B: Fermi GBM Observation
  67. Fermi GRB 241118A: Global MASTER-Net observations report
  68. GRB 241118A: Fermi GBM Final Real-time Localization
  69. GRB 241117A: SVOM/GRM observation of a short burst with extended emission
  70. GRB 241117A: Fermi GBM Detection
  71. Fermi GRB 241117B: Global MASTER-Net observations report
  72. GRB 241117B: Fermi GBM Final Real-time Localization
  73. GRB 241115B: Swift/BAT-GUANO localization skymap of a long burst
  74. Fermi GRB 241117A: Global MASTER-Net observations report
  75. GRB 241117A: Fermi GBM Final Real-time Localization
  76. GRB 241115C: Fermi GBM Observation
  77. EP241115a/GRB 241115D: Optical upper limits with Kinder observations
  78. GRB 241115A: Mephisto upper limits
  79. GRB 241113B: Mephisto upper limits
  80. GRB 241115D / EP 241115a: SVOM/GRM observation
  81. The EP-WXT trigger 01709120856 is likely a flaring star
  82. GRB 241115A: Fermi GBM Observation
  83. GRB 241115A: LCOGT Optical Upper Limits
  84. GRB 241115C: Swift/BAT-GUANO localization skymap of a burst
  85. Fermi GRB 241115B: Global MASTER-Net observations report
  86. EP241115a: Global MASTER-Net observations report
  87. GRB 241115B: Fermi GBM Final Real-time Localization
  88. EP241115a: EP detection of a fast X-ray transient
  89. EP241113a: No Detection in Fermi-GBM Observations
  90. Swift GRB 241115A: Global MASTER-Net observations report
  91. Fermi GRB 241115A: Global MASTER-Net observations report
  92. GRB 241115A: Swift detection of a burst
  93. GRB 241115A: Fermi GBM Final Real-time Localization
  94. GRB 241113B: KAIT Optical Afterglow Candidate
  95. LIGO/Virgo/KAGRA S241114bi: Upper limits from Fermi-GBM Observations
  96. LIGO/Virgo/KAGRA S241114bi: Coverage and upper limits from MAXI/GSC observations
  97. GRB 241113A: Swift-BAT refined analysis
  98. Fermi GRB 241114A: Global MASTER-Net observations report
  99. EP241113a: Global MASTER-Net observations report
  100. GRB 241114A: Fermi GBM Final Real-time Localization

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