Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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"

45430 results found.

  1. Fermi Gamma-ray Burst Monitor trigger 240812940/745194848 is not a GRB
  2. Fermi Gamma-ray Burst Monitor trigger 240812917/745192855 is not a GRB
  3. Fermi Gamma-ray Burst Monitor trigger 240812917/745192855 is not a GRB
  4. GRB 240809A: ATA radio non-detection
  5. GRB 240812D: Fermi GBM Final Real-time Localization
  6. GRB 240812C: Fermi GBM Final Real-time Localization
  7. GRB 240809A : RAPAS follow-up observations
  8. GRB 240809A: VLA detection
  9. GRB 240809A: ALMA detection
  10. IPN triangulation of GRB 240810A (short)
  11. GRB 240811A: Swift-BAT refined analysis
  12. GRB 240809A: Swift-BAT refined analysis
  13. EP240807a: PRIME H-band upper limits
  14. GRB 240812B: AstroSat CZTI detection of a long burst
  15. IceCube-240808A: Upper limits from a search for additional neutrino events in IceCube
  16. GRB 240811A: Bassano Bresciano Observatory upper limit
  17. GRB 240811A: Swift-XRT refined Analysis
  18. Fermi Gamma-ray Burst Monitor trigger 745135620/240812255 is not a GRB
  19. GRB 240811A: Swift/UVOT Upper Limits
  20. EP240801a: Assy-Turgen optical observations
  21. Fermi GRB 240810A: Global MASTER-Net observations report
  22. Fermi Gamma-ray Burst Monitor trigger 240812094/745121685 is not a GRB
  23. GRB 240812A: Fermi GBM Final Real-time Localization
  24. GRB 240811A: LCOGT Optical Upper Limit
  25. GRB 240811A: Enhanced Swift-XRT position
  26. GRB 240811A: Upper limits with Mephisto
  27. Konus-Wind detection of GRB 240809A
  28. Fermi trigger No 745057312: Global MASTER-Net observations report
  29. Swift GRB 240811A: Global MASTER-Net observations report
  30. GRB 240811A: Swift detection of a burst
  31. Fermi Gamma-ray Burst Monitor trigger 745050426/240811269 is not a GRB
  32. GRB 240810A: Fermi GBM Final Real-time Localization
  33. GRB 240809A: REM detection of the optical afterglow
  34. GRB 240809A: Bassano Bresciano Observatory optical observations
  35. Konus-Wind detection of GRB 240807A (a counterpart of EP240807a)
  36. GRB 240809A: Conclusive redshift from VLT
  37. Fermi-LAT gamma-ray observations of IceCube-240808A
  38. GRB 240809A: KAIT optical observations
  39. GRB 240808A: AstroSat CZTI detection
  40. GRB 240809A: GIT afterglow observations
  41. GRB 240809B: MAXI/GSC detection
  42. GRB 240809A: Swift/UVOT Detection
  43. GRB 240809A: Tentative redshift from NOT
  44. GRB 240809A: Swift-XRT refined Analysis
  45. IPN triangulation of GRB 240807A / EP 240807a
  46. LIGO/Virgo/KAGRA S240807h: Updated Sky localization and EM Bright Classification
  47. X-ray Transient EP240807a: PRIME near-infrared upper limits
  48. Swift GRB 240809A: Global MASTER-Net observations report
  49. GRB 240809A: JinShan optical observations
  50. GRB 240809A: Enhanced Swift-XRT position
  51. GRB 240809A: Skynet & Photon Ranch Optical Afterglow Observations
  52. GRB 240809A: SVOM/GRM observation
  53. GRB 240808A: SVOM/GRM observation
  54. GRB 240807A: SVOM/GRM observation
  55. GRB 240809A: Swift detection of a burst with a bright optical counterpart
  56. EP-WXT trigger 01709018832: SVOM/C-GFT observations of the star flare
  57. EP240807a: STEP/T80S optical limits
  58. GRB 240807B: AstroSat CZTI detection of a short burst
  59. IceCube Alert 240808.27: Global MASTER-Net observations report
  60. EP EP240807a: Global MASTER-Net observations report
  61. EP EP240806a: Global MASTER-Net observations report
  62. IceCube-240808A - IceCube observation of a high-energy neutrino candidate track-like event
  63. GRB 240801A: GRBAlpha detection
  64. GRB 240807B: Fermi GBM Final Localization
  65. GRB 240710B: VZLUSAT-2 detection
  66. GRB 240805A: ATCA Radio Upper Limits
  67. Fermi trigger No 744761058: Global MASTER-Net observations report
  68. EP240807a/GRB 240807A: EP-FXT detection of the X-ray emission
  69. S240807h: Identification of a GW compact binary merger candidate
  70. EP-WXT trigger 01709018832: KAIT optical observations of the star flare
  71. EP240802a/GRB240802A: KAIT optical upper limit
  72. GRB 240720B: VZLUSAT-2 detection
  73. GRB 240710A: VZLUSAT-2 detection
  74. EP240806A: Liverpool Telescope optical follow-up observations
  75. The EP-WXT trigger 01709018832 on August 7th is likely a flaring star
  76. GRB 240807A: Fermi GBM Final Localization
  77. EP240807a: EP-WXT detection of a fast X-ray transient
  78. EP240806a: Gemini North-GMOS spectroscopic redshift of z = 2.818
  79. GRB 240805B: GIT optical upper limit
  80. EP240806a: KAIT optical observations
  81. GRB 240805B: Swift-BAT refined analysis
  82. GRB 240805A: Swift-BAT refined analysis
  83. Fermi trigger No 744629911: Global MASTER-Net observations report
  84. EP240804a (GRB 240804B): NOT optical observations
  85. EP240806a: LCOGT optical counterpart detection
  86. Konus-Wind detection of GRB 240802A (EP240802a)
  87. Improved IPN triangulation of GRB 240802A / EP 240802a
  88. Konus-Wind detection of GRB 240805A
  89. GRB 240805B Bassano Bresciano Observatory upper limit
  90. GRB240805A: Fermi GBM Observation
  91. GRB 240805B: JinShan optical afterglow detection
  92. GRB 240804B/EP240804a: Correction to the GRB name in GCN 37071
  93. GRB 240805B: AbAO, CrAO, and Terskol optical upper limits
  94. Konus-Wind detection of GRB 240804B (a counterpart of EP240804a)
  95. Fermi Gamma-ray Burst Monitor trigger 240806402/744629911 is not a GRB
  96. EP240806a: EP-FXT detection of the X-ray emission
  97. GRB 240626B: VZLUSAT-2 detection
  98. GRB 240624B: VZLUSAT-2 detection
  99. GRB 240619C: VZLUSAT-2 detection
  100. EP 240806A: LCO optical 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