Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. 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"

12173 results found.

  1. GRB 210204A (ZTF21aagwbjr/AT2021buv): continued CrAO and AbAO optical observations
  2. GRB 210212A: Possible host galaxy counterpart with the NOT
  3. GRB 210212A: Swift-XRT refined Analysis
  4. Fermi-LAT Gamma-ray Observations of IceCube-210210A
  5. Fermi GRB 210210B: Global MASTER-Net observations report
  6. GRB 210210A: Swift/UVOT Detection
  7. GRB 210112A: LBT host detection and correction to GCN 29319 (CAHA observations)
  8. GRB 210210A: Swift-XRT refined Analysis
  9. GRB 210210A: Swift detection of a burst with an optical counterpart
  10. GRB 210207B: AstroSat CZTI detection
  11. GRB 210204A: LBT observations and jet break
  12. GRB 210208A: A long GRB detected by INTEGRAL
  13. GRB 210207B: Swift-XRT refined Analysis
  14. Konus-Wind detection of GRB 210207B
  15. SGR 1935+2154: MAXI/GSC detection
  16. Konus-Wind detection of GRB 210204A (correction to GCN 29415)
  17. Konus-Wind detection of GRB 210204A / ZTF21aagwbjr
  18. GRB 210204A / ZTF21aagwbjr: Swift-XRT observations
  19. GRB 210204A: AstroSat CZTI Detection
  20. GRB 210205A: Swift-BAT refined analysis
  21. IPN triangulation of GRB 210204A
  22. Fermi GRB 210204A: Global MASTER-Net observations report
  23. GRB 210202A: AGILE/MCAL detection
  24. Fermi GBM Observations of a bright burst from SGR J1935+2154
  25. GRB 210202A: Fermi GBM detection
  26. GRB 210202A: Fermi-LAT detection
  27. Recent activity of SGR 1935+2154 as observed by CGBM
  28. GRB 210202A: BALROG localization (Fermi Trigger / GRB 210202841)
  29. INTEGRAL detection of a short burst from SGR 1935+2154
  30. GRB 210202A: Fermi GBM Final Real-time Localization
  31. GECAM observations of SGR 1935+2154
  32. Continued Chandra observations of GW170817 at ~3.3 years since merger
  33. Fermi GBM Observations of SGR J1935+2154
  34. Konus-Wind detection of two bright bursts from SGR 1935+2154
  35. GRB 140330A: Swift-XRT refined Analysis
  36. GRB 140320B: Swift-XRT refined Analysis
  37. GRB 210126A: AstroSat CZTI detection
  38. GRB 210124B: AstroSat CZTI detection
  39. GRB 210123A: AstroSat CZTI detection
  40. IPN triangulation of a bright burst from SGR 1935+2154
  41. GECAM detection of a short burst probably from SGR 1935+2154
  42. GRB 210120A: Fermi GBM detection
  43. Konus-Wind detection of GRB 210121A
  44. Konus-Wind detection of GRB 210124B
  45. IPN triangulation of GRB 210124B (short)
  46. IPN triangulation of GRB 210121A
  47. GRB 210120A : 1.3m DFOT optical observations
  48. GRB 210116A: AstroSat CZTI detection
  49. GRB 210120A(MASTER OT J105242.66+152355.0 / AT2021axc): Mondy optical observations
  50. GRB 210116: AstroSat LAXPC detection
  51. GRB 210120A: MASTER OT (possibly) discovery
  52. GECAM In-Flight Trigger of GRB 210120A
  53. Fermi GRB 210120A: Global MASTER-Net observations report
  54. GRB 210120A: BALROG localization (Fermi Trigger 632819449 / GRB 210120299)
  55. GRB 210120A: Fermi GBM Final Real-time Localization
  56. GRB 210119A (Swift J1851.2-6148): Swift-BAT refined analysis
  57. GECAM detection of a short GRB 210119A or a new SGR candidate Swift J1851.2-6148
  58. GRB 210119A: Fermi GBM observation
  59. Short Fermi GRB 210119A or new SGR Swift J1851.2-6148: Possible MASTER Short OT detection
  60. Fermi GRB 210119A: Global MASTER-Net observations report
  61. Swift detection of a new SGR Swift J1851.2-6148 or a short GRB 210119A
  62. Konus-Wind detection of GRB 210112A
  63. GRB 201221D: near-infrared observation with LBT
  64. GRB 210112A: Mondy optical observations
  65. GRB 210104A: AstroSat CZTI detection
  66. NuEm-210111A: MAXI/GSC upper limit
  67. GRB 210104A: AROMA-N Optical Afterglow Detection
  68. GRB 210110A: MAXI/GSC detection
  69. GRB 210104A: Assy continued optical observations, correction to GCN circ. 29265
  70. GRB 210109A: MAXI/GSC detection
  71. GRB 201227A: continued Chilescope confirmation of variability of possible optical counterpart, redshift estimating
  72. Correction to GCN 29278: GRB 201216C XRT refined analysis
  73. GRB 201216C: Swift-XRT refined Analysis
  74. GRB 210104A: SAO RAS optical observations
  75. GRB 210104A: SARA-KP 0.9m Optical Afterglow Detection
  76. GRB 210102B: Assy optical afterglow identification
  77. GRB 210104A: Assy continued optical observations
  78. Fermi GRB 210105A: Global MASTER-Net observations report
  79. GRB 210104A: Swift-XRT refined Analysis
  80. Konus-Wind detection of GRB 210104A
  81. GRB 210104B: Assy optical upper limit
  82. GRB 210104A: Swift/UVOT Detection
  83. Swift GRB210104.88: Global MASTER-Net observations report
  84. GRB 210102B: Assy optical observations
  85. Fermi GRB 210104A: Global MASTER-Net observations report
  86. GRB 210104A: Assy optical observations
  87. Fermi GRB 210102C: Global MASTER-Net observations report
  88. GRB 210102C: Fermi GBM detection
  89. GRB 210102C: Swift detection of a burst
  90. GRB 210102B: MAXI/GSC detection
  91. Fermi GRB 210101A: Global MASTER-Net observations report
  92. Swift GRB210102.01: Global MASTER-Net observations report
  93. Fermi trigger No 631226368: Global MASTER-Net observations report
  94. Fermi trigger No 631119348: Global MASTER-Net observations report
  95. Fermi trigger No 631113166: Global MASTER-Net observations report
  96. Fermi trigger No 631118376: Global MASTER-Net observations report
  97. Fermi trigger No 631104264: Global MASTER-Net observations report
  98. GRB 201216C: TSHAO, Terskol, Mondy optical upper limits
  99. Baksan Neutrino Observatory Alert 201230.40: Global MASTER-Net observations report
  100. GRB 201229A: AbAO optical afterglow detection, TSHAO optical upper limit

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