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"

3406 results found.

  1. GRB 200325B: further Swift-XRT observations
  2. GRB 200325B: Swift-XRT and UVOT observations
  3. GRB 200324A: Swift-XRT refined Analysis
  4. Chandra observations of GW170817 at 2.5 years since merger (All epochs 4 of 4)
  5. GW170817: Continued X-ray emission detected with Chandra at 940 days post-merger
  6. LIGO/Virgo S200316bj: No counterpart candidates in Fermi-LAT observations
  7. LIGO/Virgo S200213t: Continued Swift UVOT and XRT observations of ZTF20aamvmzj (AT2020cja)
  8. LIGO/Virgo S200311bg: No significant counterpart candidates in Fermi-LAT observations
  9. Chandra observations of GW170817 ~ 2.5 years since merger (epoch 1 of 4)
  10. GRB 200306C: Swift-XRT refined Analysis
  11. GRB 200306A: Swift-XRT refined Analysis
  12. GRB 200303A: Swift-XRT refined Analysis
  13. LIGO/Virgo S200302c: No significant counterpart candidates in Fermi-LAT observations
  14. GRB 200228B: Swift-XRT refined Analysis
  15. GRB 200227A: Swift-XRT refined Analysis
  16. LIGO/Virgo S200225q: No counterpart candidates in Fermi-LAT observations
  17. LIGO/Virgo S200224ca: No counterpart candidates in Fermi-LAT observations
  18. GRB 200219C: Swift-XRT afterglow confirmation
  19. GRB 200224A: Swift-XRT refined Analysis
  20. GRB 200219C: Swift-XRT afterglow detection
  21. LIGO/Virgo S200213t: Swift UVOT and XRT observations of ZTF20aamvmzj (AT2020cja)
  22. LIGO/Virgo S200219ac: No counterpart candidates in Fermi-LAT observations
  23. GRB 200219A: Swift-XRT refined Analysis correction
  24. GRB 200219A: Swift-XRT refined Analysis
  25. GRB 200216B: Swift-XRT refined Analysis
  26. Further Swift-XRT observations of Swift J0840.7-3516
  27. GRB 200215A: Swift-XRT refined Analysis
  28. LIGO/Virgo S200213t: No candidates found in J-GEM follow-up observations
  29. LIGO/Virgo S200213t: No counterpart candidates in Fermi-LAT observations
  30. LIGO/Virgo S200208q: No counterpart candidates in Fermi-LAT observations
  31. GRB 200205B: ESO/NTT near-infrared imaging
  32. GRB 200205B: Swift-XRT refined Analysis
  33. GRB 200131A: Swift-XRT refined Analysis
  34. LIGO/Virgo S200129m: No counterpart candidates in Fermi-LAT observations
  35. LIGO/Virgo S200128d: No counterpart candidates in Fermi-LAT observations
  36. GRB 200127A: Swift-XRT refined Analysis
  37. GRB 200125A: Further Swift-XRT observations
  38. GRB 200125A: TNG detection of a NIR counterpart candidate
  39. Correction to GRB 200125A: Swift-XRT refined analysis
  40. GRB 200125A: Swift-XRT refined Analysis
  41. LIGO/Virgo S200115j: Further Swift-XRT sources
  42. GRB 200122A: Swift-XRT refined Analysis
  43. GRB 191031D: XMM-Newton upper limit
  44. LIGO/Virgo S200115j: NIR upper limits for ZTF20aafqvyc/AT2020yq from the Palomar 200-inch telescope
  45. LIGO/Virgo S200114f: No transients found in J-GEM observations of nearby galaxies
  46. LIGO/Virgo S200115j: Swift-XRT sources
  47. LIGO/Virgo S200114f: Swift-XRT sources and observations
  48. LIGO/Virgo S200115j: No counterpart candidates in Fermi-LAT observations
  49. LIGO/Virgo S200114f: No counterpart candidates in Fermi-LAT observations
  50. LIGO/Virgo 200112r: No counterpart candidates in Fermi-LAT observations
  51. GRB 200107B: Swift-XRT refined Analysis
  52. GRB 200109A: Swift-XRT refined Analysis
  53. LIGO/Virgo 200105ae: No counterpart candidates in Fermi-LAT observations
  54. Fermi trigger No 599954133: Global MASTER-Net observations report
  55. GRB 191228A: Swift-XRT refined Analysis
  56. GRB 191227A: Marginal detection by Fermi-LAT
  57. GRB 191221B: Swift-XRT refined Analysis
  58. LIGO/Virgo S191222n: No counterpart candidates in Fermi-LAT observations
  59. GRB 191220A: Swift-XRT refined Analysis
  60. LIGO/Virgo S191213g: Swift UVOT/XRT observations of Pan-STARRS1 candidate: PS19hgw
  61. LIGO/Virgo S191216ap: No candidates found in J-GEM follow-up observations of HAWC error region
  62. LIGO/Virgo S191213g: No candidates found in J-GEM follow-up observations
  63. LIGO/Virgo S191216ap and IceCube neutrino: Swift XRT sources
  64. LIGO/Virgo S191213g: Swift UVOT/XRT observations of three ZTF sources
  65. LIGO/Virgo G191216ap: No counterpart candidates in Fermi-LAT observations
  66. LIGO/Virgo S191215w: No counterpart candidates in Fermi-LAT observations
  67. LIGO/Virgo S191213g: No counterpart candidates in Fermi-LAT observations
  68. Possible HAWC-detected GRB 191210A: Fermi-LAT Upper Limits
  69. Possible HAWC-detected GRB 191210A: Swift-XRT observations
  70. Fermi trigger No 597737032: Global MASTER-Net observations report
  71. LIGO/Virgo S191205ah: No counterpart candidates in Fermi-LAT observations
  72. LIGO/Virgo S191204r: No counterpart candidates in Fermi-LAT observations
  73. GRB 191130A: Swift-XRT observations
  74. LIGO/Virgo S191129u: No counterpart candidates in Fermi-LAT observations
  75. GRB 191123A: Swift-XRT refined Analysis
  76. GRB 191122A: Swift-XRT refined Analysis
  77. LIGO/Virgo S191110af: Swift XRT observations, no secure afterglow found
  78. LIGO/Virgo S191110af: No counterpart candidates in Fermi-LAT observations
  79. LIGO/Virgo S191109d: No counterpart candidates in Fermi-LAT observations
  80. LIGO/Virgo S191105e: No counterpart candidates in Fermi-LAT observations
  81. GRB 191106A: Swift-XRT refined Analysis
  82. GRB 191101A: Swift-XRT refined Analysis
  83. GRB 191031C: Swift-XRT refined Analysis
  84. GRB 191031D: Swift-XRT refined Analysis
  85. GRB 191029A: CORRECTED Swift-XRT refined analysis
  86. GRB 191029A: Swift/UVOT Upper Limits
  87. GRB 191029A: Swift-XRT refined Analysis
  88. Swift Trigger 931384: possible GRB 191025A
  89. GRB 191024A: Swift-XRT refined Analysis
  90. GRB 191019A: Swift-XRT updated analysis
  91. GRB 191019A: Swift-XRT refined Analysis
  92. GRB 191017B: Swift-XRT refined Analysis
  93. GRB 191016A: Swift-XRT afterglow detection
  94. GRB 191016A: Swift/UVOT Detection
  95. GRB 191011A: Swift-XRT refined Analysis
  96. LIGO/Virgo S190930t: Continued Swift observations of AT2019sbk
  97. LIGO/Virgo S190930t: Swift XRT observations, no secure afterglow found
  98. GRB 191004B: Swift-XRT refined Analysis
  99. GRB 191004A: Swift-XRT refined Analysis
  100. GRB 191001A: Swift-XRT observations

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