Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

45430 results found.

  1. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  2. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  3. EP241206a: BOOTES Global Network optical limits
  4. GRB 241207C: MASTER optical observations
  5. Fermi trigger No 755225799: Global MASTER-Net observations report
  6. GRB 241207C: Tiled Swift observations
  7. GRB 241207C: MAXI/GSC detection
  8. GRB 241207B: Fermi GBM Final Real-time Localization
  9. Fermi trigger No 755277791: Global MASTER-Net observations report
  10. Fermi GRB 241207A: Global MASTER-Net observations report
  11. EP241206a: Global MASTER-Net observations report
  12. EP241206a: EP detection of a fast X-ray transient
  13. GRB 241206A: Fermi GBM observation
  14. GRB 241206C: SVOM/GRM observation of a likely short burst
  15. GRB 241207A: Fermi GBM Final Real-time Localization
  16. GRB 241206A: Swift/BAT-GUANO localization skymap of a burst
  17. GRB 241206B: SVOM/MXT observations: a probable flare from the QSO 1ES 1959+650
  18. GRB 241206B: GWAC-F50A optical upper limit
  19. GRB 241206B: SVOM/ECLAIRs detection of a long soft transient
  20. EP241113a: Keck/LRIS spectroscopic observation and tentative redshift
  21. Fermi GRB 241206A: Global MASTER-Net observations report
  22. GRB 241206A: Fermi GBM Final Real-time Localization
  23. EP241201a: 1.6m Mephisto Optical Upper Limits
  24. GRB 241204A: COLIBRÍ Optical Upper Limit
  25. EP241202b: KAIT optical upper limit
  26. LIGO/Virgo/KAGRA S241125n: gamma-ray upper limits from joint observations by the LST-1 and MAGIC telescopes
  27. GRB 241204A: DDOTI Upper Limits on the Afterglow
  28. GRB 241204A: Fermi GBM Observation
  29. Fermi GRB 241204A: Global MASTER-Net observations report
  30. GRB 241130A: CALET Gamma-Ray Burst Monitor detection
  31. GRB 241128A : RAPAS follow-up observations
  32. GRB 241201A: GRBAlpha detection
  33. GRB 241204A: Fermi-LAT detection
  34. EP241202b: Upper limits from Fermi-GBM Observations
  35. IceCube-241127A: No transient candidates from the Zwicky Transient Facility
  36. EP241202b: Kinder optical counterpart candidate
  37. Fermi-GBM Sub-Threshold Detection of GRB 241128A
  38. GRB 241113B : RAPAS follow-up observation
  39. EP241201a: EP-FXT follow-up observations
  40. Konus-Wind detection of GRB 241130A
  41. EP241202b: Global MASTER-Net observations report
  42. EP241201a: BOOTES-5 optical upper limit
  43. EP241202b: EP detection of a fast X-ray transient
  44. EP241201a: NOT optical observations
  45. IPN triangulation of GRB 241130A
  46. GRB 241130A: EIRSAT-1 GMOD Detection
  47. GRB 241128A: Swift/UVOT Upper Limits
  48. GRB 241130A: Fermi GBM Detection
  49. IceCube-241127A: Upper limits from a search for additional neutrino events in IceCube
  50. GRB 241129A: Swift/BAT-GUANO localization skymap of a burst
  51. EP241201a: Kinder optical counterpart candidate
  52. LIGO/Virgo/KAGRA S241102br: GRAWITA wide-field optical observations
  53. EP241201a: Global MASTER-Net observations report
  54. EP241201a: EP detection of a fast X-ray transient
  55. The EP-WXT trigger 01709126243 is not a real source
  56. GRB 241127B: detection of a long GRB by SVOM/ECLAIRs
  57. GRB241201B: Fermi GBM Final Localization
  58. GRB241201B: Fermi GBM Final Localization
  59. LIGO/Virgo/KAGRA S241201ac: Updated Sky localization
  60. EP241126a: SOAR observations of the optical counterpart
  61. Fermi GRB 241201A: Global MASTER-Net observations report
  62. GRB 241201A: BALROG localization (Fermi Trigger 754757764 / GRB 241201622)
  63. GRB 241130A: Fermi GBM Final Real-time Localization
  64. GRB 241130A: Fermi GBM Final Real-time Localization
  65. EP241126a: 1.6m Mephisto Optical Upper Limits
  66. GRB 241201A: Fermi GBM Final Real-time Localization
  67. LIGO/Virgo/KAGRA S241201ac: Identification of a GW compact binary merger candidate
  68. LIGO/Virgo/KAGRA S241130be: Updated Sky localization
  69. Fermi trigger No 754701230: Global MASTER-Net observations report
  70. IPN triangulation of GRB 241128B
  71. Konus-Wind detection of GRB 241114B
  72. LIGO/Virgo/KAGRA S241130n: Updated Sky localization
  73. LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
  74. GRB 241128A: AbAO optical upper limit
  75. LIGO/Virgo/KAGRA S241127aj: Updated Sky localization
  76. LIGO/Virgo/KAGRA S241130be: Identification of a GW compact binary merger candidate
  77. LIGO/Virgo/KAGRA S241129aa: Updated Sky localization
  78. LIGO/Virgo/KAGRA S241130n: Identification of a GW compact binary merger candidate
  79. SVOM/GRM observation of a short burst from soft gamma repeater Kes 73
  80. GRB 241128C: SVOM/GRM observation
  81. GRB 241128B: SVOM/GRM observation
  82. GRB 241128A: Swift-BAT refined analysis
  83. GRB 241127A: Swift-BAT refined analysis
  84. EP241126a: NOT optical observations
  85. GRB 241127A: PRIME near-infrared detection
  86. GRB 241128A: Mondy optical observations
  87. GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
  88. Swift-XRT observations of IceCube -241127A
  89. Swift GRB 241128A: Global MASTER-Net observations report
  90. Fermi-LAT gamma-ray observations of IceCube-241127A
  91. EP241126a: SVOM/VT observations
  92. LIGO/Virgo/KAGRA S241129aa: Identification of a GW compact binary merger candidate
  93. GRB 241128A: Swift-XRT refined Analysis
  94. GRB 241129A: Fermi GBM Final Real-time Localization
  95. GRB 241128A: Enhanced Swift-XRT position
  96. GRB 241128A: NOT optical observations
  97. GRB 241128A: LCO optical detection
  98. GRB 241128A: 1.5m OSN optical afterglow detection
  99. LIGO/Virgo S241127aj: GRANDMA/FRAM-CTA-N Observations
  100. Fermi trigger No 754492985: Global MASTER-Net observations report

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov