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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"

23627 results found.

  1. GRB 241209A: Swift detection of a short burst
  2. GRB 241206A: DDOTI Upper Limit on the Afterglow
  3. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  4. EP241206a: BOOTES Global Network optical limits
  5. GRB 241207C: MAXI/GSC detection
  6. GRB 241206B: SVOM/MXT observations: a probable flare from the QSO 1ES 1959+650
  7. EP241113a: Keck/LRIS spectroscopic observation and tentative redshift
  8. GRB 241206A: Fermi GBM Final Real-time Localization
  9. GRB 241204A: COLIBRÍ Optical Upper Limit
  10. EP241202b: KAIT optical upper limit
  11. LIGO/Virgo/KAGRA S241125n: gamma-ray upper limits from joint observations by the LST-1 and MAGIC telescopes
  12. GRB 241204A: DDOTI Upper Limits on the Afterglow
  13. GRB 241130A: CALET Gamma-Ray Burst Monitor detection
  14. GRB 241201A: GRBAlpha detection
  15. EP241202b: Upper limits from Fermi-GBM Observations
  16. EP241202b: Kinder optical counterpart candidate
  17. Konus-Wind detection of GRB 241130A
  18. EP241201a: BOOTES-5 optical upper limit
  19. EP241201a: NOT optical observations
  20. IPN triangulation of GRB 241130A
  21. GRB 241130A: EIRSAT-1 GMOD Detection
  22. EP241201a: Kinder optical counterpart candidate
  23. Konus-Wind detection of GRB 241114B
  24. LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
  25. LIGO/Virgo/KAGRA S241130be: Identification of a GW compact binary merger candidate
  26. LIGO/Virgo/KAGRA S241130n: Identification of a GW compact binary merger candidate
  27. GRB 241128A: Swift-BAT refined analysis
  28. GRB 241127A: Swift-BAT refined analysis
  29. GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
  30. Fermi-LAT gamma-ray observations of IceCube-241127A
  31. EP241126a: SVOM/VT observations
  32. LIGO/Virgo/KAGRA S241129aa: Identification of a GW compact binary merger candidate
  33. GRB 241128A: Swift-XRT refined Analysis
  34. GRB 241128A: LCO optical detection
  35. LIGO/Virgo S241127aj: GRANDMA/FRAM-CTA-N Observations
  36. GRB 241128A: Swift detection of a burst
  37. GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
  38. GRB 241127A: LCOGT (40-cm) optical counterpart detection
  39. LIGO/Virgo/KAGRA S241125n: Update on Coincidence False Alarm Method
  40. GRB 241127A: Swift detection of a burst with an optical counterpart
  41. Swift GRB241127.91: Global MASTER-Net OT detection
  42. LIGO/Virgo/KAGRA S241125n: Swift-UVOT Upper Limits
  43. LIGO/Virgo/KAGRA S241127aj: NED Galaxies in the Localization Volume
  44. EP241126a: Optical Upper limits with Kinder observations
  45. EP241126a: EP-FXT follow-up observation update
  46. EP241126a: GSP detects optical counterpart
  47. EP241126a: TRT optical counterpart detection
  48. LIGO/Virgo/KAGRA S241127aj: Identification of a GW compact binary merger candidate
  49. EP241126a: EP detection of a fast X-ray transient
  50. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on Optical Counterparts to Two of the Swift/XRT Sources
  51. GRB 241113B: EP-FXT afterglow detection
  52. LIGO/Virgo/KAGRA S241125n: DDOTI Optical Upper Limits
  53. LIGO/Virgo S241125n: Swift XRT observations, 5 X-ray sources
  54. Konus-Wind detection of GRB 241115D / EP 241115a
  55. LIGO/Virgo/KAGRA S241125n: Upper limits from Konus-Wind observations
  56. GRB 241026A: radio detection with the VLA
  57. EP241125a: Optical upper limit with Kinder observations
  58. LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on a Optical Counterpart at the BAT Position
  59. LIGO/Virgo/KAGRA S241125n: Kinder optical upper limit in the BAT error region
  60. GRB 241120A: GRBAlpha detection
  61. GRB 241113B: SVOM/VT optical afterglow observations
  62. LIGO/Virgo/KAGRA S241125n: Identification of a GW compact binary merger candidate
  63. Konus-Wind detection of GRB 241117A
  64. IPN triangulation of GRB 241117A
  65. Konus-Wind detection of GRB 241120A
  66. GRB241120A: OHP/T193 optical observations
  67. GRB 241120A: CALET Gamma-Ray Burst Monitor detection
  68. EP241021a and EP241026b: Keck/LRIS spectroscopic observations
  69. EP trigger ID 01709065118: Keck/LRIS spectroscopic observations
  70. EP-WXT trigger 01709018832: Lick/Kast spectroscopy with the 3 m Shane telescope
  71. EP241119a: Optical upper limits with Kinder observations
  72. EP trigger ID 01709122294: the X-ray transient is likely a stellar flare event
  73. EP241119a : J-band observations with WINTER
  74. GRB 241115A: CALET Gamma-Ray Burst Monitor detection
  75. GRB 241115A: Swift-XRT afterglow detection
  76. LIGO/Virgo/KAGRA S241116cq: Identification of a GW compact binary merger candidate
  77. EP241115a/GRB 241115D: Optical upper limits with Kinder observations
  78. GRB 241113B: Mephisto upper limits
  79. EP241115a/GRB 241115D: Swift/XRT follow-up observation
  80. The EP-WXT trigger 01709120856 is likely a flaring star
  81. GRB 241115A: Fermi GBM Observation
  82. EP241115a: EP detection of a fast X-ray transient
  83. EP241113a: No Detection in Fermi-GBM Observations
  84. Swift GRB 241115A: Global MASTER-Net observations report
  85. GRB 241115A: Swift detection of a burst
  86. GRB 241113B: KAIT Optical Afterglow Candidate
  87. LIGO/Virgo/KAGRA S241114bi: Coverage and upper limits from MAXI/GSC observations
  88. GRB 241113A: Swift-BAT refined analysis
  89. LIGO/Virgo/KAGRA S241114bi: Identification of a GW compact binary merger candidate
  90. GRB 241113B: J-band upper limit from WINTER
  91. GRB 241113A: J-band observations with WINTER
  92. EP241113a : J-band observations with WINTER
  93. GRB 241030A: LCO optical observation
  94. GRB 241113B: Swift-XRT observations
  95. GRB 241113A: 1.6m Mephisto and 50cm array optical upper limits
  96. GRB 241113A: KAIT optical observations
  97. EP241113b: Global MASTER-Net observations report
  98. EP241113b/GRB 241113B: EP detection of GRB 241113B
  99. Fermi-LAT gamma-ray observations of IceCube-241113A
  100. EP241113a: EP on-board trigger and autonomous follow-up observation

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