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"

32567 results found.

  1. GRB 260228A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  2. EP260227a: Mephisto optical detection
  3. GRID detection of GRB 260225D
  4. EP-WXT trigger 01709258652: 50cm Telescope multi-band observations
  5. EP260227a: further LCO observations
  6. EP260227a: SVOM/VT optical observation
  7. GRB 260228A: SVOM/VT optical upper limits
  8. GRB 260225D: SVOM/GRM observation
  9. EP260227A: 3.6m DOT optical afterglow detection
  10. GRB 260225B: SVOM/GRM observation
  11. EP260227a: FTW optical and NIR observations
  12. EP260227a: Liverpool Telescope optical observations
  13. EP260227a: LCOGT Optical Observations
  14. GRB 260226A: Asiago r-band upper limit
  15. EP260227a: Thai National Telescope observations
  16. EP260227a: likely GTC/OSIRIS+ redshift z = 2.714
  17. EP260227a: Liverpool Telescope observations
  18. EP260227a: COLIBRÍ optical observations
  19. EP260227a: NOT optical observations
  20. GRB 260225A: SVOM/VT optical continued observations and upper limit
  21. GRID detection of GRB 260223A
  22. EP260227a: Global MASTER-Net observations report
  23. EP260227a: Einstein Probe detection of an X-ray transient and refined analysis
  24. The EP-WXT trigger 01709258681 (EP260227a?): Las Cumbres follow-up observation of the optical counterpart
  25. GRB 260226A: Insight-HXMT/HE detection of the very bright burst
  26. Konus-Wind detection of GRB 260226A
  27. GRB 260223A: 7DT detection and Medium-band SED of Afterglow
  28. EP260214a: VLT/FORS2 optical observations
  29. GRB 260225A: WINTER J-band upper limit
  30. GRB 260226A: CALET Gamma-Ray Burst Monitor detection
  31. GRB 260226A: COLIBRÍ optical upper limits
  32. GRB 260226A: LCOGT Optical Upper Limit
  33. EP-WXT trigger 01709258652: SVOM/C-GFT confirmation of a stellar flare
  34. GRB 260226A: Glowbug gamma-ray detection
  35. GRB 260226A: NuSTAR detection of bright prompt emission
  36. GRB 260226A : GROWTH-India Telescope optical observations
  37. GRB 260226A: LAST optical upper limit
  38. GRB 260226A: Fermi GBM observation
  39. GRB 260226A: Fermi-LAT refined analysis
  40. Fermi GRB 260226A: Global MASTER-Net observations report
  41. GRB 260226A: AstroSat CZTI detection of bright long burst
  42. EP260214a: VLA 6 GHz detection
  43. GRB 260226A: Fermi-LAT detection of a bright burst
  44. EP260224a: LCO optical upper limits
  45. GRB260225A: SVOM/ECLAIRs refined position
  46. GRB 260225A: EP-FXT follow-up observation
  47. GRB 260225A: SVOM/VT optical observation
  48. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) Detection of an Optical Counterpart Candidate
  49. GRB 260223A: Fermi GBM Observation
  50. GRB 260225A: SVOM/VT optical upper limits
  51. EP260126a: VLA 6 GHz detection
  52. EP260223a: Liverpool Telescope upper limits
  53. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  54. EP 260225.148: COLIBRÍ Confirmation of flaring star
  55. EP260223a: Xinglong optical upper limit
  56. GRB 260223A: Glowbug gamma-ray detection
  57. EP260213a: Mephisto optical upper limits
  58. EP260223a: EP-FXT follow-up observation
  59. sb26021801: SVOM/VT optical upper limits
  60. GRB 260223A: COLIBRÍ optical afterglow decay confirmation
  61. sb26021801: SVOM/C-GFT upper limit
  62. EP260223a: COLIBRÍ optical upper limits
  63. GRB 260223A: SVOM/VT optical observation
  64. GRB 260223A: SVOM/GRM observation
  65. GRB 260223A: COLIBRÍ further optical observations and a brightening
  66. EP260221a: Optical upper limit with Kinder observations
  67. GRB 260223A: COLIBRÍ optical observations
  68. GRB 260223A: DDOTI Optical Candidate
  69. Fermi GRB 260223A: Global MASTER-Net observations report
  70. EP260221a: Liverpool Telescope detection of COLIBRÍ counterpart candidate
  71. EP260221a: COLIBRÍ optical counterpart candidate
  72. EP260221a: Gemini South z-band upper limit
  73. EP260221a: Global MASTER-Net observations report
  74. EP260221a: EP-FXT follow-up observation
  75. Fermi GRB 260221B: Global MASTER-Net observations report
  76. EP260221a: Xinglong optical upper limit
  77. Fermi GRB 260221A: Global MASTER-Net observations report
  78. EP260221a: GOTO optical upper limit
  79. EP260221a: COLIBRÍ optical upper limit
  80. SVOM alert sb26021801: LCO optical upper limit
  81. GRB 260219A: AstroSat CZTI detection
  82. IceCube-260217A: Upper limits from a search for additional neutrino events in IceCube
  83. GRB 260219A: GECAM-B observation of a long burst
  84. Fermi GRB 260219A: Global MASTER-Net observations report
  85. SVOM alert sb26021801: LAST optical upper limit
  86. sb26021801: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  87. Fermi-LAT Gamma-ray Observations of IceCube-260217A
  88. GRB 260214B/EP260214b: SVOM/ECLAIRs detection through targeted search
  89. EP260214b: Mondy optical observations
  90. EP260214b: 1.3m DFOT optical upper limit
  91. EP260210a: Mondy optical upper limits
  92. Konus-Wind detection of GRB 260212A
  93. GRB 260208A: AbAO and Terskol optical upper limits
  94. GRB 260208A: continued Mondy optical observations
  95. IPN triangulation of GRB 260212A
  96. IceCube-260217A - IceCube observation of a high-energy neutrino candidate track-like event
  97. GRB 260213A: GECAM-B observation of a short burst
  98. EP260214b: Liverpool Telescope optical observations
  99. GRB 260206A: probable hard X-ray burst from 4U 0513-40
  100. EP260214b: Optical upper limit with Kinder 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