Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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"

26375 results found.

  1. GRB030226, BVRc observations
  2. Chandra detection of the X-ray afterglow of GRB 030226
  3. GRB030227: Kiso optical upper limit
  4. GRB030227, BVRcIc field photometry
  5. GRB030226, BVRcIc field calibration
  6. GRB 030228, optical observations
  7. GRB 030227: Confirmed Optical Afterglow (S1-A)
  8. GRB 030227: fading of candidate optical afterglow 'S1-A'
  9. GRB030227:Optical observations
  10. GRB 030227, possible optical counterpart of XMM-Newton source
  11. GRB030227 - faint tentative OT candidate
  12. GRB 030226, optical observations
  13. XMM-Newton observation of GRB030227
  14. GRB030227: Kiso optical observations
  15. GRB 030227: Kyoto optical observation
  16. GRB 030226, optical light curve
  17. GRB030227 localized by INTEGRAL
  18. GRB 030226 : Predicted light curve
  19. GRB030226: ESI spectroscopy
  20. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  21. GRB 030226 simultaneous optical observations
  22. GRB 030226, optical observations
  23. GRB030226: Optical decay index
  24. GRB 030226 Optical Spectra and R,I,z' Imaging
  25. GRB: Non-Referencing of GCN Circulars.
  26. IPN triangulation of GRB030217 (small error box)
  27. GRB 030131: marginal optical detection
  28. GRB 030204: Optical Observations
  29. GRB030204 field photometry
  30. GRB020819: Kiso R and I band observations
  31. GRB030131: Candidate Optical Afterglow
  32. IPN triangulation of GRB030204 (small error box)
  33. GRB 030131, optical observations
  34. GRB 030131: afterglow candidate
  35. GRB 030115, late-time optical observations
  36. GRB030131: corrected INTEGRAL position
  37. GRB 020819: Host galaxy at Radio Position
  38. IPN triangulation of GRB030131
  39. GRB 030131 optical observations
  40. GRB 030131 optical observations
  41. A long GRB detected by INTEGRAL
  42. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  43. GRB 030115, simultaneous observations by BOOTES-1
  44. GRB 030115: IR observations with IRSF/SIRIUS
  45. IPN triangulation of GRB030115C (large error box)
  46. GRB030115, afterglow candidate
  47. GRB 021211: R-band observations at late-time
  48. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  49. GRB 030115 : Possible IR counterpart
  50. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  51. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  52. GRB 030115: APO Optical Observations
  53. Information about where HETE will be pointing
  54. VLT spectroscopy of the probable host of GRB 021211
  55. IPN triangulation of GRB030101 (two large error boxes)
  56. GRB 021211: Probable Host and Underlying Supernova
  57. GRB 021112: Evidence for Another Dark Optical Afterglow
  58. GRB 021219: OSN optical observations
  59. GRB021219, optical observations
  60. GRB021219, optical observation by MASTER
  61. VLT spectra of GRB 021211 revisited
  62. GRB021219: a long GRB localized by INTEGRAL
  63. GRB021211: APO optical observations
  64. XRF 020903 : HST observations
  65. GRB 021201: Optical Observations
  66. GRB 021211: CTIO observations
  67. GRB021211, BVRI field photometry
  68. GRB021211: Optical observations in CrAO
  69. GRB 021211, optical observations
  70. GRB021211: Kiso Observations
  71. GRB 021201, optical observations
  72. GRB021211: Optical observations
  73. GRB 021201 (short/hard), NOT observations
  74. SUB-MM SEARCH FOR GRB 021211
  75. Chandra observation of the IPN error box of GRB021201 (short/hard)
  76. GRB 021211, R- and I-band observations
  77. GRB021211 - Upper limits from recent and historical observations
  78. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  79. IPN triangulation of GRB021206 (small error box)
  80. IPN triangulation of GRB021205 (large error box)
  81. GRB021201, BVRcIc field photometry
  82. GRB 021201: BOOTES simultaneous optical observations
  83. IPN triangulation of GRB021201 (short/hard burst, small error box)
  84. GRB021004, late time optical observations
  85. GRB021004 Chandra Observation
  86. IPN detection of continued SGR1900+14 activity
  87. Improved IPN error box for GRB021125
  88. IPN BURST POSITION
  89. IPN triangulation of GRB021125 (INTEGRAL BURST)
  90. GRB021125 : A long GRB localized by INTEGRAL
  91. IPN confirmation of the reactivation of SGR1900+14
  92. GRB021113, SPI ACS observation
  93. GRB 021112: Afterglow or Variable Star?
  94. GRB021113: optical observations at Bisei
  95. GRB 021113: Evidence for a Dark Optical Afterglow
  96. GRB021112, BVRI field photometry
  97. GRB 021112: Variable Source in R-band search
  98. GRB021112: Optical Observations
  99. IPN triangulation of GRB021113 (=H2449; annulus)
  100. GRB 021113: Optical observations

Advanced

Download all Circulars as a .tar.gz archive:
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