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"

41639 results found.

  1. RXTE detection of GRB 030329 afterglow
  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 030329: OT candidate
  12. GRB 030329: Optical afterglow candidate
  13. GRB 030328: OT photometry
  14. GRB030328: optical spectroscopy at TNG
  15. GRB030328: optical photometry at the TNG
  16. VLT spectra of GRB 030328
  17. GRB 030328, optical spectroscopy
  18. GRB 030328, optical observations
  19. GRB 030328: Optical observations
  20. GRB 030328: Optical afterglow candidate
  21. GRB030323 optical observations
  22. GRB030324 optical observation
  23. GRB030131, BVRcIc field photometry
  24. Possible GRB030323 localized by INTEGRAL
  25. GRB030323: Detection on 2003/03/24
  26. GRB 030323: SARA Optical Observations
  27. GRB030324, optical observations
  28. GRB030324, optical observations
  29. GRB 030324: TAROT optical observations
  30. GRB030323: V, R, I photometry
  31. GRB 030324 (HETE #2641): Optical observations
  32. GRB030324, Optical Observations
  33. GRB030323: Upper limits from recent and historical observations.
  34. VLT/FORS2 spectra of GRB 030323
  35. GRB030323, optical observations
  36. GRB030324, BVRcIc field photometry
  37. GRB030323, possible optical counterpart
  38. GRB030323, BVRcIc field calibration
  39. GRB 030324 optical observations
  40. GRB 030320: Optical Observations
  41. GRB 030324, optical observations
  42. IPN triangulation of GRB030320
  43. GRB030226, addendum to GCN 1892
  44. IPN upper limit to a GRB associated with SN2003L
  45. GRB 030227: Optical limit at RIKEN
  46. GRB 030226 Optical observations
  47. GRB030226: Optical observations at Asiago
  48. IPN triangulation of GRB030306 (single small error box)
  49. IPN triangulation of GRB030306 (intense; annulus only so far)
  50. GRB 030226: Optical observations
  51. GRB030226: Analysis of Chandra data
  52. GRB 030227: Optical observations
  53. GRB030226, BVRc observations
  54. Chandra detection of the X-ray afterglow of GRB 030226
  55. GRB 030226, further optical/NIR imaging
  56. GRB030227, optical observations
  57. GRB 030226: Ic Observations
  58. GRB030227: Kiso optical upper limit
  59. GRB030227, BVRcIc field photometry
  60. GRB030226, BVRcIc field calibration
  61. GRB 030227 optical afterglow
  62. GRB 030228, optical observations
  63. GRB 030226: Steep Decline
  64. GRB 030227: Confirmed Optical Afterglow (S1-A)
  65. GRB 030226: R band polarimetric observations
  66. GRB 030226: Optical observations
  67. GRB 030227: fading of candidate optical afterglow 'S1-A'
  68. GRB030227:Optical observations
  69. GRB 20030226: Upper limits from recent and historical observations
  70. GRB 030227, possible optical counterpart of XMM-Newton source
  71. GRB030227 - faint tentative OT candidate
  72. GRB 030226, optical observations
  73. XMM-Newton observation of GRB030227
  74. GRB030227: Kiso optical observations
  75. GRB 030227: Kyoto optical observation
  76. GRB 030226, optical light curve
  77. GRB 030226 spectroscopy
  78. GRB030227: refined INTEGRAL position
  79. GRB030227 localized by INTEGRAL
  80. Possible break in the GRB 030226 light curve
  81. GRB 030226 : Predicted light curve
  82. GRB030226: optical observation
  83. GRB 030226: Confirmed decay index
  84. GRB030226: ESI spectroscopy
  85. GRB 030226 simultaneous optical observations
  86. Two absorption systems in GRB 030226
  87. GRB 030226, optical observations
  88. GRB030226: optical observations and refined redshift
  89. GRB030226: Optical decay index
  90. GRB 030226 Optical Spectra and R,I,z' Imaging
  91. GRB 030226, optical observations
  92. GRB 030226: Optical afterglow
  93. GRB030226: Candidate optical afterglow
  94. GRB 030217: Optical Observations at 4, 5, and 6 Days
  95. GRB030217: optical observations
  96. IPN triangulation of GRB030217 (small error box)
  97. IPN triangulation of GRB030215A and GRB030215B (annuli)
  98. GRB030115, WSRT radio observations - correction to GCN 1864
  99. GRB 030131: marginal optical detection
  100. GRB030115, WSRT radio 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