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"

28704 results found.

  1. GRB 211024B: Host galaxy redshift from X-shooter/VLT
  2. GRB 220325A: Swift-BAT refined analysis
  3. ZTF22aaajecp/AT2022cmc: continued optical observations (Mondy, TSHAO, AbAO)
  4. GRB 220325A: Tautenburg observations
  5. GRB 220325A: LCO Optical Upper Limits
  6. GRB 220325A: Swift-XRT refined Analysis
  7. GRB 220325A: 1.3m DFOT Optical upper limit
  8. Fermi GBM Sub-Threshold Detection of GRB 220325A
  9. GRB 220325A: MASTER Global Robotic Net optical observations
  10. GRB 220323A: AstroSat CZTI detection
  11. GRB 220319A: GRANDMA observations
  12. GRB 220323A: AGILE/MCAL detection
  13. IPN triangulation of GRB 220320A
  14. GRB 220319A: Swift-BAT refined analysis
  15. GRB 220316A: AstroSat CZTI detection
  16. GRB 220320A: AstroSat CZTI detection
  17. GRB 220317A: Fermi GBM detection
  18. GRB 220319A: MITSuME Akeno optical upper limits
  19. GRB220319A: Optical observations from NOT
  20. GRB 220319A: LCO Optical Upper Limit
  21. GRB 220319A: Mondy optical uper limit
  22. GRB 220319A: Swift-XRT refined Analysis
  23. GRB 220319A: MASTER Global Robotic Net optical observations
  24. Fermi-LAT Gamma-ray Observations of IceCube-220317A
  25. GRB 220317A: Swift/BAT-GUANO detection outside the coded FOV
  26. GRB 220310A: MITSuME Akeno optical observation
  27. IceCube-220317A: MASTER Global Robotic Net optical observations
  28. GRB 220315A: MASTER Global Robotic Net optical observations
  29. GRB 220311A: Fermi GBM observation
  30. GRB 220306B: Swift/UVOT Upper Limits
  31. GRB 220311A: MITSuME Akeno optical upper limits
  32. IPN triangulation of GRB 220310A
  33. GRB 220310C: Fermi GBM observation
  34. GRB 210722A: TAROT Reunion observatory optical light curve
  35. GRB 210222B: TAROT Reunion observatory optical light curve
  36. GRB 201021C: TAROT Reunion observatory optical light curve
  37. GRB 220310A: K-800 of Terskol observatory optical upper limit
  38. GRB 220310A: [KAO-Egypt] SDSS r, i observation
  39. Konus-Wind detection of GRB 220310A
  40. GRB 220310C: Swift ToO observations
  41. GRB 220310C: Swift/BAT-GUANO candidate arcminute localization
  42. GRB 220311A: MASTER OT retraction
  43. ZTF22aabjpxh/AT2022cva (GRB 220219B): evidence of supernova in LBT spectra
  44. GRB 220310A: GIT confirmation of optical afterglow.
  45. GRB 220306B: Nanshan/NEXT optical upper limit
  46. ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, possible photometric evidence of SN
  47. Fermi GBM Detection of GRB 220308A
  48. GRB 220308A: AGILE detection
  49. GRB 220310A: MASTER optical counterpart detection
  50. GRB 220310A: Swift ToO observations
  51. GRB 220310A: CALET Gamma-Ray Burst Monitor detection
  52. ZTF22aaajecp/AT2022cmc: Hubble Space Telescope Observations
  53. Fermi GRB 220310B: Global MASTER-Net observations report
  54. Konus-Wind detection of GRB 220308A
  55. IceCube-220306A: No significant detection in HAWC
  56. IceCube-220303A: No significant detection in HAWC
  57. ZTF22aabjpxh/AT2022cva: AMI-LA radio observation
  58. CALET Gamma-Ray Burst Monitor detection of GRB 220308A and its possible precursor
  59. Fermi GRB 220309A: Global MASTER-Net observations report
  60. GRB 220308A: Swift/BAT-GUANO detection outside the coded FOV
  61. IPN triangulation of GRB 220308A (long / very bright)
  62. GRB 220306B: Mondy optical observations, confirmation afterglow candidate
  63. IPN triangulation of GRB 220305B
  64. GRB 220306B: Tautenburg observations
  65. GRB 220304A Fermi GBM detection
  66. GRB 220306B: Swift-BAT refined analysis
  67. Fermi-LAT Gamma-ray Observations of IceCube-220306A
  68. GRB 220306B: AbAO optical observations, possible afterglow candidate
  69. GRB 220306B: Swift-XRT refined Analysis
  70. GRB 220306B: Fermi GBM observation
  71. Fermi-LAT Gamma-ray Observations of IceCube-220304A
  72. Swift GRB 220306B: Global MASTER-Net observations report
  73. GRB 220305A: Swift-BAT refined analysis
  74. Fermi GBM Sub-Threshold Detection of GRB 220305A
  75. GRB 220305A: Swift-XRT refined Analysis
  76. Fermi GRB 220306A: Global MASTER-Net observations report
  77. Fermi GRB 220305A: Global MASTER-Net observations report
  78. Correction to GCN 31689: Fermi GBM Report of GRB 220305A should be GRB 220305B
  79. IceCube-220303A: One X-ray counterpart from Swift/XRT follow up observations
  80. Swift GRB 220305A: Global MASTER-Net observations report
  81. ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, SN signature search
  82. GRB 220302A: Swift/UVOT Upper Limits
  83. Fermi-LAT Gamma-ray Observations of IceCube-220303A
  84. GRB 220304A: Swift/BAT-GUANO detection outside the coded FOV
  85. Fermi GRB 220304A: Global MASTER-Net observations report
  86. GRB 220302A: Swift-XRT refined Analysis
  87. ZTF22aaajecp/AT2022cmc: AMI-LA radio detection
  88. ZTF22aaajecp/AT2022cmc: ATCA detection
  89. GRB 220302A: Swift afterglow detection
  90. GRB 220222A: CALET Gamma-Ray Burst Monitor detection
  91. Swift GRB 220302A: Global MASTER-Net observations report
  92. GRB 220228A: Fermi GBM observation
  93. GRB 220228A: Fermi-LAT detection
  94. Konus-Wind detection of GRB 220222A
  95. ZTF22aaajecp/AT2022cmc: JCMT SCUBA-2 sub-mm observations
  96. Fermi-LAT Gamma-ray Observations of IceCube-220225A
  97. ZTF22aaajecp/AT2022cmc: Mondy optical observations
  98. IPN triangulation of GRB 220222A
  99. GRB 220101A: The first example of a Petanova
  100. Konus-Wind observation of GRB 220219B

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