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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"

37308 results found.

  1. GRB 241128A: NOT optical observations
  2. GRB 241128A: LCO optical detection
  3. GRB 241128A: 1.5m OSN optical afterglow detection
  4. GRB 241128A: Swift-XRT afterglow detection
  5. GRB 241128A: Swift detection of a burst
  6. GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
  7. GRB 241127A: Swift/UVOT Detection
  8. GRB 241127A: Swift-XRT refined Analysis
  9. GRB 241127A: SVOM/GRM observation
  10. GRB 241127A: Enhanced Swift-XRT position
  11. GRB 241127A: LCOGT (40-cm) optical counterpart detection
  12. GRB 241127A: Swift detection of a burst with an optical counterpart
  13. LIGO/Virgo/KAGRA S241125n: Preliminary flux estimate and spectral analysis of the Swift/BAT-GUANO candidate counterpart
  14. EP241126a: Optical Upper limits with Kinder observations
  15. SVOM/GRM observation of GRB 241126B or a short burst from magnetar
  16. GRB 241126A: SVOM/GRM observation
  17. IPN triangulation of GRB 241114B
  18. EP trigger ID 01709122294: 1.6m Mephisto multi-band optical observations
  19. EP241126a: EP detection of a fast X-ray transient
  20. GRB 241113B: EP-FXT afterglow detection
  21. Konus-Wind detection of GRB 241115D / EP 241115a
  22. LIGO/Virgo/KAGRA S241125n: Upper limits from Konus-Wind observations
  23. GRB 241026A: radio detection with the VLA
  24. EP241125a: Optical upper limit with Kinder observations
  25. EP241125a: EP detection of an X-ray transient
  26. LIGO/Virgo/KAGRA S241125n: Upper limits from Fermi-GBM Observations
  27. LIGO/Virgo/KAGRA S241125n: Kinder optical upper limit in the BAT error region
  28. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  29. LIGO/Virgo/KAGRA S241125n: No counterpart candidates in INTEGRAL SPI-ACS prompt observation, comparisong with Swift/BAT counterpart
  30. LIGO/Virgo/KAGRA S241125n: Updated Sky localization and Coincidence with External Event
  31. LIGO/Virgo/KAGRA S241125n: Swift/BAT-GUANO candidate counterpart
  32. GRB 241120A: GRBAlpha detection
  33. GRB 241113B: SVOM/VT optical afterglow observations
  34. Konus-Wind detection of GRB 241117A
  35. GRB 241105A: ATCA radio detection
  36. IPN triangulation of GRB 241117A
  37. GRB 241026A: VIRT Optical Upper Limit
  38. GRB 241025A: VIRT Optical Upper Limit
  39. Konus-Wind detection of GRB 241120A
  40. GRB 241120A: CALET Gamma-Ray Burst Monitor detection
  41. EP241021a and EP241026b: Keck/LRIS spectroscopic observations
  42. EP trigger ID 01709065118: Keck/LRIS spectroscopic observations
  43. EP-WXT trigger 01709018832: Lick/Kast spectroscopy with the 3 m Shane telescope
  44. GRB 241120A: Mondy and AbAO optical observations
  45. EP241119a: Optical upper limits with Kinder observations
  46. GRB 241113A: Possible ATCA Radio detection
  47. GRB 241120A: Fermi GBM Observation
  48. GRB 241114B: Insight-HXMT/HE detection
  49. EP241119a: EP detection of a fast X-ray transient
  50. GRB241120A: a long GRB detected by INTEGRAL
  51. GRB 241120A: Fermi GBM Final Real-time Localization
  52. GRB 241115A: CALET Gamma-Ray Burst Monitor detection
  53. GRB 241112B: Mephisto further optical observations
  54. GRB 241119A: Fermi GBM Final Real-time Localization
  55. GRB 241030A: J-band observations
  56. GRB 241115a: PRIME near-infrared upper limits
  57. GRB 241117A: Swift/BAT-GUANO localization skymap of a burst
  58. LIGO/Virgo/KAGRA S241116cq: Upper limits from Swift/BAT-GUANO
  59. GRB 241115B: Fermi GBM Observation
  60. Fermi GRB 241118A: Global MASTER-Net observations report
  61. GRB 241118A: Fermi GBM Final Real-time Localization
  62. GRB 241117A: SVOM/GRM observation of a short burst with extended emission
  63. GRB 241117A: Fermi GBM Detection
  64. Fermi GRB 241117B: Global MASTER-Net observations report
  65. GRB 241117B: Fermi GBM Final Real-time Localization
  66. GRB 241115B: Swift/BAT-GUANO localization skymap of a long burst
  67. Fermi GRB 241117A: Global MASTER-Net observations report
  68. GRB 241117A: Fermi GBM Final Real-time Localization
  69. GRB 241115C: Fermi GBM Observation
  70. GRB 241115A: Swift-XRT afterglow detection
  71. EP241115a/GRB 241115D: Optical upper limits with Kinder observations
  72. GRB 241115A: Mephisto upper limits
  73. GRB 241113B: Mephisto upper limits
  74. EP241115a/GRB 241115D: Swift/XRT follow-up observation
  75. GRB 241115D / EP 241115a: SVOM/GRM observation
  76. GRB 241115A: Fermi GBM Observation
  77. GRB 241115A: LCOGT Optical Upper Limits
  78. GRB 241115C: Swift/BAT-GUANO localization skymap of a burst
  79. Fermi GRB 241115B: Global MASTER-Net observations report
  80. GRB 241115B: Fermi GBM Final Real-time Localization
  81. EP241113a: No Detection in Fermi-GBM Observations
  82. Swift GRB 241115A: Global MASTER-Net observations report
  83. Fermi GRB 241115A: Global MASTER-Net observations report
  84. GRB 241115A: Swift detection of a burst
  85. GRB 241115A: Fermi GBM Final Real-time Localization
  86. GRB 241113B: KAIT Optical Afterglow Candidate
  87. LIGO/Virgo/KAGRA S241114bi: Upper limits from Fermi-GBM Observations
  88. LIGO/Virgo/KAGRA S241114bi: Coverage and upper limits from MAXI/GSC observations
  89. GRB 241113A: Swift-BAT refined analysis
  90. GRB 241113A: PRIME near-infrared upper limits
  91. Fermi GRB 241114A: Global MASTER-Net observations report
  92. GRB 241114A: Fermi GBM Final Real-time Localization
  93. GRB 241113B: J-band upper limit from WINTER
  94. GRB 241113A: J-band observations with WINTER
  95. GRB 241030A: LCO optical observation
  96. GRB 241113B: Swift-XRT observations
  97. GRB 241113A: 1.6m Mephisto and 50cm array optical upper limits
  98. GRB 241113A: KAIT optical observations
  99. EP241113b/GRB 241113B: EP detection of GRB 241113B
  100. GRB 241113B: SVOM/GRM observation

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