Skip to main content
New! BOOM Notices and Schema v7.0.0. 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"

4169 results found.

  1. GRB 210307B: GECAM detection
  2. GRB 210306A: Tautenburg observations
  3. GRB 210228A: GECAM detection
  4. GRB 210226A: Fermi GBM detection
  5. GRB 210222A: MAXI/GSC detection
  6. GRB 210205A: observations with the 3.6m DOT, a potential dark burst?
  7. Fermi/GBM observation of a burst from SGR 1830-0645
  8. GRB 210212A: Mondy optical observations
  9. GRB 210210A: Konus-Wind detection and joint Konus-Wind + Swift-BAT spectral analysis
  10. Swift Trigger 1033144: Detection of SGR 1830-0645
  11. Swift Trigger 1032350: Detection of SGR 1830-0645
  12. GRB 210204A: observations with the 3.6m Devasthal Optical Telescope and possible jet break
  13. GRB 210207B: GECAM detection
  14. GRB 210211A: Fermi GBM observation
  15. Swift-XRT observations of IceCube-210210A
  16. Fermi trigger No 634659312: Global MASTER-Net observations report
  17. SGR 1935+2154: MAXI/GSC detection
  18. GRB 210207B: optical detection with 3.6m Devasthal Optical Telescope
  19. Fermi GRB 210207A: Global MASTER-Net observations report
  20. GRB 210204A: Optical Observations from HCT
  21. IPN triangulation of GRB 210204A
  22. GRB 210205A: MITSuME Ishigaki optical observation
  23. GRB 210204: Fermi GBM observation
  24. GRB 210204A: GECAM detection
  25. GRB 210204A: BALROG localization (Fermi Trigger 634112970 / GRB 210204270)
  26. GRB 210204A: Fermi GBM Final Real-time Localization
  27. Fermi GBM Observations of a bright burst from SGR J1935+2154
  28. Recent activity of SGR 1935+2154 as observed by CGBM
  29. INTEGRAL detection of a short burst from SGR 1935+2154
  30. GRB 210131A: GECAM detection
  31. Fermi trigger No 633879387: Global MASTER-Net observations report
  32. GECAM observations of SGR 1935+2154
  33. Fermi GBM Observations of SGR J1935+2154
  34. Konus-Wind detection of two bright bursts from SGR 1935+2154
  35. IPN triangulation of a bright burst from SGR 1935+2154
  36. GECAM detection of a short burst probably from SGR 1935+2154
  37. GRB 210120A: Fermi GBM detection
  38. GRB 210126A: GECAM detection
  39. IPN triangulation of GRB 210124B (short)
  40. GECAM detection of a burst possibly from the X-ray burster 4U 0614+09 or GRB 210124A
  41. GRB 210121A: GECAM detection
  42. GECAM In-Flight Trigger of GRB 210120A
  43. Fermi GRB 210120A: Global MASTER-Net observations report
  44. GRB 210119A (Swift J1851.2-6148): Swift-BAT refined analysis
  45. GECAM detection of a short GRB 210119A or a new SGR candidate Swift J1851.2-6148
  46. GRB 210119A: Fermi GBM observation
  47. Short Fermi GRB 210119A or new SGR Swift J1851.2-6148: Possible MASTER Short OT detection
  48. Swift detection of a new SGR Swift J1851.2-6148 or a short GRB 210119A
  49. ZTF21aaeyldq: observations with the 3.6m Devasthal Optical Telescope
  50. GRB 210112A: OSN second epoch, decay
  51. GRB 210104A: AROMA-N Optical Afterglow Detection
  52. GRB 201227A: continued Chilescope confirmation of variability of possible optical counterpart, redshift estimating
  53. Fermi trigger No 631584650: Global MASTER-Net observations report
  54. GRB 210104A: MASTER OT rebrightening detection
  55. Fermi GRB 210104A: Global MASTER-Net observations report
  56. Fermi GRB 210102C: Global MASTER-Net observations report
  57. MAXI GRB210102.38: Global MASTER-Net observations report
  58. Fermi GRB 210101A: Global MASTER-Net observations report
  59. Fermi trigger No 631119348: Global MASTER-Net observations report
  60. Fermi trigger No 631118376: Global MASTER-Net observations report
  61. Fermi trigger No 631104264: Global MASTER-Net observations report
  62. GRB 201227A: Chilescope optical observations, possible optical counterpart
  63. GRB 201229A: AbAO optical afterglow detection, TSHAO optical upper limit
  64. GRB 201229A: Nanshan/NEXT optical upper limit
  65. GRB 201227A: Swift-XRT observations
  66. Fermi GRB 201229B: Global MASTER-Net observations report
  67. GRB 201229B: BALROG localization (Fermi Trigger 630948017 / GRB 201229639)
  68. GRB 201229B: Fermi GBM Final Real-time Localization
  69. ZTF20acozryr/AT2020yxz (GRB 201103B): Maidanak optical observations
  70. Fermi trigger No 630681391: Global MASTER-Net observations report
  71. GRB 201223A: Mondy and Kitab optical observations
  72. Konus-Wind detection of GRB 201216C
  73. GRB 201216C: AstroSat CZTI detection
  74. Fermi GRB 201216A: Global MASTER-Net observations report
  75. GRB 201015A: 5-GHz radio afterglow detection with the EVN
  76. Swift GRB201209.24: Global MASTER-Net observations report
  77. Swift GRB 201203A: Global MASTER-Net observations report
  78. IceCube-201130A: No significant detection in HAWC
  79. IceCube-201130A: Upper limits from a search for additional neutrino events in IceCube
  80. GRB 201121A: Insight-HXMT/HE detection
  81. INTEGRAL Weak #8831 and #8832: AROMA-N Optical Observation
  82. GRB 201121A: BALROG localization (Fermi Trigger 627614994 / GRB 201121062)
  83. GRB 201121A: Fermi GBM Final Real-time Localization
  84. IceCube-201120A: Upper limits from Fermi-GBM Observations
  85. Fermi-LAT Gamma-ray Observations of NuEm-201107A
  86. ZTF20acozryr/AT2020yxz (GRB 201103B): Mondy continued optical observations
  87. Fermi GRB 201111A: Global MASTER-Net observations report
  88. Swift Trigger 1005428: Detection of SGR 1830-0645
  89. GRB 201104B: MITSuME Akeno optical observation
  90. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-201107A
  91. IPN triangulation of GRB 201103B (consistent with ZTF20acozryr/AT2020yxz)
  92. Swift Trigger 1004219: Detection of SGR 1830-0645
  93. Swift GRB 201029A: Global MASTER-Net observations report
  94. GRB 201029A: Fermi GBM detection
  95. Fermi trigger No 625695596: Global MASTER-Net observations report
  96. GRB 201027A: Swift-BAT refined analysis
  97. GRB 201027A: 1.5m OSN optical upper limit
  98. GRB 201014A: 2.0m HCT upper limit
  99. GRB 201021C: VLT/X-shooter redshift
  100. GRB 201021C: Swift detection of a burst with an optical counterpart

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