Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. 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"

28714 results found.

  1. GRB 220401A: Swift/BAT-GUANO detection outside the coded FOV
  2. GRB 220401A: Fermi GBM observation
  3. Fermi GRB 220401B: Global MASTER-Net observations report
  4. Fermi Gamma-ray Burst Monitor trigger 220331776/670444627 is not a GRB
  5. Fermi GRB 220330A: Global MASTER-Net observations report
  6. ZTF22aaajecp/AT2022cmc: 1.3m DFOT Optical observations
  7. GRB 220325A: GRANDMA observations
  8. GRB 220320A: Detection by VZLUSAT-2
  9. Konus-Wind observation of GRB 220320A
  10. GRB 220325A: Swift/UVOT Upper Limits
  11. GRB 211024B: Host galaxy redshift from X-shooter/VLT
  12. GRB 220325A: Swift-BAT refined analysis
  13. ZTF22aaajecp/AT2022cmc: continued optical observations (Mondy, TSHAO, AbAO)
  14. GRB 220325A: Tautenburg observations
  15. GRB 220325A: LCO Optical Upper Limits
  16. GRB 220325A: Swift-XRT refined Analysis
  17. GRB 220325A: 1.3m DFOT Optical upper limit
  18. Fermi GBM Sub-Threshold Detection of GRB 220325A
  19. GRB 220325A: MASTER Global Robotic Net optical observations
  20. GRB 220323A: AstroSat CZTI detection
  21. GRB 220319A: GRANDMA observations
  22. GRB 220323A: AGILE/MCAL detection
  23. IPN triangulation of GRB 220320A
  24. GRB 220319A: Swift-BAT refined analysis
  25. GRB 220316A: AstroSat CZTI detection
  26. GRB 220320A: AstroSat CZTI detection
  27. GRB 220317A: Fermi GBM detection
  28. GRB 220319A: MITSuME Akeno optical upper limits
  29. GRB220319A: Optical observations from NOT
  30. GRB 220319A: LCO Optical Upper Limit
  31. GRB 220319A: Mondy optical uper limit
  32. GRB 220319A: Swift-XRT refined Analysis
  33. GRB 220319A: MASTER Global Robotic Net optical observations
  34. Fermi-LAT Gamma-ray Observations of IceCube-220317A
  35. GRB 220317A: Swift/BAT-GUANO detection outside the coded FOV
  36. GRB 220310A: MITSuME Akeno optical observation
  37. IceCube-220317A: MASTER Global Robotic Net optical observations
  38. GRB 220315A: MASTER Global Robotic Net optical observations
  39. GRB 220311A: Fermi GBM observation
  40. GRB 220306B: Swift/UVOT Upper Limits
  41. GRB 220311A: MITSuME Akeno optical upper limits
  42. IPN triangulation of GRB 220310A
  43. GRB 220310C: Fermi GBM observation
  44. GRB 210722A: TAROT Reunion observatory optical light curve
  45. GRB 210222B: TAROT Reunion observatory optical light curve
  46. GRB 201021C: TAROT Reunion observatory optical light curve
  47. GRB 220310A: K-800 of Terskol observatory optical upper limit
  48. GRB 220310A: [KAO-Egypt] SDSS r, i observation
  49. Konus-Wind detection of GRB 220310A
  50. GRB 220310C: Swift ToO observations
  51. GRB 220310C: Swift/BAT-GUANO candidate arcminute localization
  52. GRB 220311A: MASTER OT retraction
  53. ZTF22aabjpxh/AT2022cva (GRB 220219B): evidence of supernova in LBT spectra
  54. GRB 220310A: GIT confirmation of optical afterglow.
  55. GRB 220306B: Nanshan/NEXT optical upper limit
  56. ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, possible photometric evidence of SN
  57. Fermi GBM Detection of GRB 220308A
  58. GRB 220308A: AGILE detection
  59. GRB 220310A: MASTER optical counterpart detection
  60. GRB 220310A: Swift ToO observations
  61. GRB 220310A: CALET Gamma-Ray Burst Monitor detection
  62. ZTF22aaajecp/AT2022cmc: Hubble Space Telescope Observations
  63. Fermi GRB 220310B: Global MASTER-Net observations report
  64. Konus-Wind detection of GRB 220308A
  65. IceCube-220306A: No significant detection in HAWC
  66. IceCube-220303A: No significant detection in HAWC
  67. ZTF22aabjpxh/AT2022cva: AMI-LA radio observation
  68. CALET Gamma-Ray Burst Monitor detection of GRB 220308A and its possible precursor
  69. Fermi GRB 220309A: Global MASTER-Net observations report
  70. GRB 220308A: Swift/BAT-GUANO detection outside the coded FOV
  71. IPN triangulation of GRB 220308A (long / very bright)
  72. GRB 220306B: Mondy optical observations, confirmation afterglow candidate
  73. IPN triangulation of GRB 220305B
  74. GRB 220306B: Tautenburg observations
  75. GRB 220304A Fermi GBM detection
  76. GRB 220306B: Swift-BAT refined analysis
  77. Fermi-LAT Gamma-ray Observations of IceCube-220306A
  78. GRB 220306B: AbAO optical observations, possible afterglow candidate
  79. GRB 220306B: Swift-XRT refined Analysis
  80. GRB 220306B: Fermi GBM observation
  81. Fermi-LAT Gamma-ray Observations of IceCube-220304A
  82. Swift GRB 220306B: Global MASTER-Net observations report
  83. GRB 220305A: Swift-BAT refined analysis
  84. Fermi GBM Sub-Threshold Detection of GRB 220305A
  85. GRB 220305A: Swift-XRT refined Analysis
  86. Fermi GRB 220306A: Global MASTER-Net observations report
  87. Fermi GRB 220305A: Global MASTER-Net observations report
  88. Correction to GCN 31689: Fermi GBM Report of GRB 220305A should be GRB 220305B
  89. IceCube-220303A: One X-ray counterpart from Swift/XRT follow up observations
  90. Swift GRB 220305A: Global MASTER-Net observations report
  91. ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, SN signature search
  92. GRB 220302A: Swift/UVOT Upper Limits
  93. Fermi-LAT Gamma-ray Observations of IceCube-220303A
  94. GRB 220304A: Swift/BAT-GUANO detection outside the coded FOV
  95. Fermi GRB 220304A: Global MASTER-Net observations report
  96. GRB 220302A: Swift-XRT refined Analysis
  97. ZTF22aaajecp/AT2022cmc: AMI-LA radio detection
  98. ZTF22aaajecp/AT2022cmc: ATCA detection
  99. GRB 220302A: Swift afterglow detection
  100. GRB 220222A: CALET Gamma-Ray Burst Monitor detection

Advanced

Download all Circulars as a .tar.gz archive:
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