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"

28040 results found.

  1. NIR Observations of GRB 041219
  2. GRB041226: Swift-BAT detection of a burst
  3. GRB041223: decay of the afterglow
  4. GRB 041224: near-infrared observations with REM
  5. GRB 041223 Fluence measured by Swift-BAT
  6. GRB041223: optical and NIR observations with REM
  7. Swift-BAT Time History of GRB041219
  8. GRB 041219: TAROT optical observations
  9. GRB 041218: TAROT optical observations
  10. GRB 041223: J-band observations of the afterglow
  11. GRB 041219c: PROMPT Observations
  12. GRB041223: Swift-BAT detection of a bright long burst
  13. GRB 041218: optical observations
  14. GRB 041219 : optical follow-up observations
  15. Deep RAPTOR observations during GRB 041219
  16. GRB 041218 Optical Observations
  17. GRB041219: Continued NIR Observations
  18. GRB 041219 ,optical observation
  19. GRB 041219: Radio Afterglow Detection
  20. GRB 041218 : Radio Observations
  21. GRB 041218: R-band optical observations
  22. GRB041218: optical observations
  23. GRB041219: Confirmed NIR Afterglow
  24. Swift-BAT detection of the bright long burst GRB041219
  25. GRB 041219: Infrared Afterglow Candidate
  26. GRB041219, BVRcIc field calibration
  27. GRB 041219: Infrared Afterglow Candidate
  28. GRB041218, BVRcIc field calibration
  29. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  30. GRB 041219 - A long GRB detected by INTEGRAL
  31. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  32. GRB 041217: PROMPT Observations
  33. GRB 041217: LCO40 Optical Observations and Possible Candidates
  34. GRB 041218 - A long GRB detected by integral
  35. GRB041217: NIR and optical observations with REM
  36. GRB041217: Infrared Observations
  37. GRB041217: The First GRB Located On-Board Swift
  38. GRB041211: Faulkes Telescope continued optical monitoring
  39. Optical Transient in Lynx not a GRB
  40. Optical transient (GRB?) in Lynx
  41. GRB041211: RAPTOR observations
  42. GRB041211: Ashra Prototype optical observation
  43. GRB041211, BVRcIc field calibration
  44. GRB041211,optical observation
  45. GRB 041211: Infrared Observations
  46. GRB 041211: KAIT observations
  47. GRB 041211: Optical follow-up in East Asian region
  48. Triangulation of short GRB 041116 (large error box)
  49. GRB 040924: Afterglow Color
  50. GRB 041006: GETS Optical Afterglow Observation
  51. Summary of the recent bursts from SGR 1806-20
  52. GRB 041006: Optical Observations
  53. GRB041006, late-time optical photometry
  54. GRB041006: RTT150 Optical Observations
  55. HST Observations: XRF 040701 and 040812
  56. Bright bursts from SGR1806-20
  57. GRB 041016: BOOTES-2 simultaneous observation
  58. GRB041006: RTT150 Optical Observations
  59. GRB041016,optical observation
  60. GRB 041016: Optical limits
  61. GRB 041016:Optical limit during first minute
  62. GRB 041015: Optical Observations at Rikubetsu
  63. GRB 041016: Optical limit
  64. GRB 041015 R band observations
  65. GRB040924, BVRcIc field calibration
  66. GRB041015,optical observation
  67. GRB041006: Fading X-ray Afterglow Observed with Chandra
  68. GRB 041015 - A long GRB detected by INTEGRAL
  69. GRB041006: VLT observations of the afterglow and host galaxy
  70. GRB041006: Optical observations and Potential host galaxy
  71. GRB041006, BVRcIc field calibration
  72. GRB 040924: VLT spectroscopy
  73. GRB 041006: SARA afterglow observations
  74. GRB041006, optical observation in CrAO
  75. Search for SN light in XRF 040912 with MEGACAM
  76. GRB 041006: BR observations with VATT
  77. GRB 041006: Redshift confirmed
  78. GRB 041006: Radio Observations
  79. GRB 041006 : optical follow-up observation at Lulin Observatory
  80. GRB041006: Optical photometry and spectroscopy at TNG
  81. GRB 041006: presice astrometry
  82. GRB041006, optical I observation
  83. GRB041006 (=HETE3570): optical observations
  84. ROTSE-IIIa Observations of GRB 041006
  85. GRB041006: MASTER optical observations
  86. GRB041006,optical observation
  87. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  88. GRB041006: Fading of optical afterglow candidate
  89. GRB 041006: Optical afterglow candidate
  90. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  91. XRF 020903: Observations of the Host Galaxy
  92. radio observations, GRB 040924
  93. GRB040929,optical observation
  94. GRB040924,optical observation
  95. GRB040924,optical observation
  96. GRB 040924: detection of possible host galaxy by Subaru
  97. GRB040924: KAIT observations
  98. GRB040924 : Optical candidate observations at Lulin observatory
  99. GRB040924 : Optical candidate observations at Lulin observatory
  100. GRB 040924: Subaru NIR observation

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