Skip to main content
End of Swift Science Operations, CHIME Notices Unavailable During Upgrade. See news and announcements

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"

45839 results found.

  1. GRB 231122A: GECAM detection
  2. GRB 231122B: GECAM detection
  3. GRB 231122A: Fermi GBM Final Real-time Localization
  4. GRB 231118A: ATCA detection of radio counterpart
  5. GRB 231117A: Swift/UVOT late time observations
  6. GRB 231117A: GTC Near-Infrared Observations
  7. GRB 231117A: Swift-BAT refined analysis
  8. GRB 231118A: GRBAlpha detection
  9. LIGO/Virgo/KAGRA S231118d: Upper limits from Swift/BAT-GUANO
  10. LIGO/Virgo/KAGRA S231118an: Upper limits from Swift/BAT-GUANO
  11. LIGO/Virgo/KAGRA S231114n: Upper limits from Swift/BAT-GUANO
  12. LIGO/Virgo/KAGRA S231113bb: Upper limits from Swift/BAT-GUANO
  13. LIGO/Virgo/KAGRA S231119u: Updated Sky localization and Source Classification
  14. LIGO/Virgo/KAGRA S231118ab: Updated Sky localization and Source Classification
  15. LIGO/Virgo/KAGRA S231118d: Updated Sky localization and Source Classification
  16. GRB 231118A: VZLUSAT-2 detection
  17. GRB 231117A: AMI-LA radio observations
  18. GRB 231118A: Swift-BAT refined analysis
  19. Konus-Wind detection of GRB 231020A
  20. GRB 231117A: LDT Confirmation of Optical Fading
  21. GRB 231117A: Wendelstein Confirmation of Fading of the Optical Afterglow
  22. GRB 231118B: CALET Gamma-Ray Burst Monitor detection
  23. GRB 231117A: CALET Gamma-Ray Burst Monitor detection
  24. 231118A: Swift-UVOT Detection
  25. GRB231117A: Swift-UVOT detection
  26. GRB 231117A : MITSuME Akeno optical afterglow candidate detection
  27. GRB 231118B: Fermi GBM observation
  28. GRB 231118A: Fermi GBM observation
  29. LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
  30. GRB 231120A: Fermi GBM Final Real-time Localization
  31. GRB 231117A: Swift-XRT refined Analysis
  32. GRB 231118A: Swift-XRT refined Analysis
  33. GRB 231118A: MeerLICHT afterglow detection
  34. LIGO/Virgo/KAGRA S231119u: One counterpart neutrino candidate from IceCube neutrino searches
  35. GRB 231117A: OHP/T120 optical observations
  36. GRB 231118A: VLT/X-shooter redshift
  37. Fermi trigger No 722039659: Global MASTER-Net observations report
  38. GRB 231117A: Pan-STARRS1 follow-up confirms rapid fading
  39. LIGO/Virgo/KAGRA S231119u: Identification of a GW compact binary merger candidate
  40. GRB 231117A: MAAO 0.7-m telescope optical upper limit
  41. GRB 231117A: AKO Follow-Up Observation
  42. GRB 231117A: GECAM-C detection
  43. GRB 231118A: AstroSat CZTI detection
  44. GRB 231115A: Upper limit from CALET Gamma-Ray Burst Monitor
  45. GRB 231117A: 10 GHz VLA detection
  46. GRB 231118A: Las Cumbres optical detection
  47. GRB 231118B: BALROG localization (Fermi Trigger 722039659 / GRB 231118940)
  48. GRB 231118B: Fermi GBM Final Real-time Localization
  49. GRB 231118A: LCOGT Optical Observations
  50. GRB 231118A: MASTER OT observation
  51. GRB 231118A: Continued Skynet Observations
  52. Swift GRB231118.72: Global MASTER-Net observations report
  53. GRB 231118A: Enhanced Swift-XRT position
  54. GRB 231117A: Kinder observations with Lulin observatory for AT 2023yba without fading in r band
  55. GRB 231118A: Swift-XRT position
  56. GRB 231118A: Skynet Optical Afterglow Discovery
  57. GRB 231117A: SOAR/Goodman imaging of the afterglow
  58. GRB 231118A: Swift detection of a burst
  59. GRB 231118A: Fermi GBM Final Real-time Localization
  60. GRB 231117A: Lowell Discovery Telescope Observations
  61. GRB 231117A: ePESSTO+ host galaxy redshift confirmation
  62. GRB 231117A: ATCA detection of a radio counterpart
  63. LIGO/Virgo/KAGRA S231118an: Identification of a GW compact binary merger candidate
  64. GRB 231117A: GRBAlpha detection
  65. LIGO/Virgo/KAGRA S231118ab: Identification of a GW compact binary merger candidate
  66. GRB 231117A: Keck spectroscopy of afterglow candidate
  67. GRB 231115A: Wendelstein Optical/Infrared Observations
  68. GRB 231115A: JinShan optical upper limits
  69. LIGO/Virgo/KAGRA S231118d: Identification of a GW compact binary merger candidate
  70. GRB 231117A: GIT optical follow-up
  71. GRB 231117A: LT observations consistent with fading
  72. GRB 231117A: Keck observations indicate presence of optical afterglow in z~0.3-0.5 galaxy
  73. GRB 231117A: REM optical and NIR early-time observations
  74. GRB231117A: AGILE/MCAL analysis
  75. GRB 231117A: AKO Optical Upper Limit
  76. GRB 231117A: afterglow candidate detection from Kinder observations with Lulin observatory
  77. Swift GRB 231117A: Global MASTER-Net observations report
  78. GRB 231117A (short): Glowbug gamma-ray detection
  79. GRB 231117A: ATLAS non-detection of an optical counterpart
  80. Konus-Wind detection of GRB 231117A (short/hard)
  81. GRB 231115A : OHP/T120 optical upper limit
  82. GRB 231115A: optical observations from INAF observatories
  83. GRB 231117A : MITSuME Akeno optical upper limits
  84. GRB 231117A: AGILE detection of a bright short burst
  85. GRB 231117A: Enhanced Swift-XRT position
  86. GRB 231117A: GOTO optical upper limits
  87. GRB 231117A: AstroSat CZTI detection of a bright short burst
  88. GRB 231117A: Swift detection of a bright short burst
  89. GRB 231115A: Non-detection of radio emission with CHIME/FRB
  90. GRB 231111A: Swift/UVOT Detection
  91. MAGIC observation of GRB 231115A, a possible magnetar giant flare
  92. GRB231115A: Liverpool Telescope imaging
  93. GRB 231115A: NuSTAR Follow-Up Observations
  94. GRB 231115A: Swift/BAT-GUANO detection of a short burst
  95. GRB 231115A: Swift-XRT and Swift-UVOT observations
  96. Fermi GRB 231116A: Global MASTER-Net observations report
  97. Konus-Wind detection of GRB 231115A (a probable Magnetar Giant Flare from M82)
  98. GRB 231115A: AGILE/MCAL upper limits
  99. GRB 231115A: Insight-HXMT/HE detection
  100. GRB 231115A: GBM/Fermi Observations of a probable Giant Flare of Magnetar

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov