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"

21791 results found.

  1. GRB030329: Upper limits from recent and historical observations.
  2. GRB 030329: Optical Afterglow Observations
  3. GRB 030329: precise position from Kyoto images
  4. GRB 030328 Optical Observations
  5. GRB030328: Decay index
  6. GRB 030328: Optical observations
  7. GRB 030328: optical observations
  8. GRB 030329: Optical afterglow fading
  9. GRB 030329 follow-up
  10. GRB 030329: Optical afterglow candidate
  11. GRB 030328: OT photometry
  12. GRB030328: optical spectroscopy at TNG
  13. GRB030328: optical photometry at the TNG
  14. GRB 030328, optical observations
  15. GRB 030328: Optical observations
  16. GRB 030328: Optical afterglow candidate
  17. GRB030323 optical observations
  18. GRB 030323: SARA Optical Observations
  19. GRB030324, optical observations
  20. GRB030324, optical observations
  21. GRB 030324: TAROT optical observations
  22. GRB030323: V, R, I photometry
  23. GRB 030324 (HETE #2641): Optical observations
  24. GRB030324, Optical Observations
  25. GRB030323: Upper limits from recent and historical observations.
  26. VLT/FORS2 spectra of GRB 030323
  27. GRB030323, optical observations
  28. GRB030324, BVRcIc field photometry
  29. GRB030323, possible optical counterpart
  30. GRB030323, BVRcIc field calibration
  31. GRB 030324 optical observations
  32. GRB 030320: Optical Observations
  33. GRB 030324, optical observations
  34. GRB030226, addendum to GCN 1892
  35. GRB 030226 Optical observations
  36. GRB030226: Optical observations at Asiago
  37. GRB 030226: Optical observations
  38. GRB 030227: Optical observations
  39. GRB030226, BVRc observations
  40. GRB 030226, further optical/NIR imaging
  41. GRB030227, optical observations
  42. GRB 030226: Ic Observations
  43. GRB 030228, optical observations
  44. GRB 030226: Steep Decline
  45. GRB 030226: R band polarimetric observations
  46. GRB 030226: Optical observations
  47. GRB030227:Optical observations
  48. GRB 20030226: Upper limits from recent and historical observations
  49. GRB 030227, possible optical counterpart of XMM-Newton source
  50. GRB 030226, optical observations
  51. GRB030227: Kiso optical observations
  52. GRB 030226, optical light curve
  53. GRB030226: optical observation
  54. GRB030226: ESI spectroscopy
  55. GRB 030226 simultaneous optical observations
  56. GRB 030226, optical observations
  57. GRB030226: optical observations and refined redshift
  58. GRB030226: Optical decay index
  59. GRB 030226, optical observations
  60. GRB030226: Candidate optical afterglow
  61. GRB 030217: Optical Observations at 4, 5, and 6 Days
  62. GRB030217: optical observations
  63. GRB030115, WSRT radio observations - correction to GCN 1864
  64. GRB 030131: marginal optical detection
  65. GRB030115, WSRT radio observations
  66. GRB 030204: Optical Observations
  67. GRB020819: Kiso R and I band observations
  68. GRB030131: Candidate Optical Afterglow
  69. GRB 030115: Optical Observations
  70. GRB 030204, optical observations
  71. GRB 030131, optical observations
  72. GRB030131: Optical limits for corrected position
  73. GRB 030115, late-time optical observations
  74. GRB030131: Kiso Observations
  75. GRB 020819: Host galaxy at Radio Position
  76. GRB030131: Optical limit
  77. GRB 030131 optical observations
  78. GRB 030131 optical observations
  79. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  80. Type Ic SN2003L (SN/GRB?) Radio Observations
  81. GRB030115 submm upper limit
  82. GRB 030115: Further IR observations with IRSF/SIRIUS
  83. GRB 030115: Radio detection of IR candidate
  84. GRB 030115, simultaneous observations by BOOTES-1
  85. GRB 030115: IR observations with IRSF/SIRIUS
  86. GRB030115: R-band counterpart of IR candidate
  87. GRB 021211: R-band observations at late-time
  88. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  89. GRB 030115 : Possible IR counterpart
  90. GRB 030115: Radio Observations
  91. GRB030115: R-band observations at Asiago
  92. GRB030115: TAROT optical observations
  93. GRB 021211: VLT spectrum
  94. GRB 030115: APO Optical Observations
  95. GRB 030115, no optical candidate
  96. GRB 030115, optical observations
  97. GRB 030115, optical candidate
  98. Information about where HETE will be pointing
  99. VLT spectroscopy of the probable host of GRB 021211
  100. GRB 021211: Probable Host and Underlying Supernova

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