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"

21770 results found.

  1. GRB 030329: Optical Afterglow Observations
  2. GRB 030328: optical observations
  3. GRB 030329: Optical afterglow fading
  4. GRB 030329: Optical afterglow candidate
  5. GRB 030328: OT photometry
  6. GRB030328: optical photometry at the TNG
  7. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  8. GRB 030328: Optical observations
  9. GRB030324 optical observation
  10. GRB030131, BVRcIc field photometry
  11. Possible GRB030323 localized by INTEGRAL
  12. GRB030323: Detection on 2003/03/24
  13. GRB030324, optical observations
  14. GRB030323: V, R, I photometry
  15. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  16. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  17. VLT/FORS2 spectra of GRB 030323
  18. GRB030323, ROTSE-III detection of possible optical counterpart
  19. GRB030323, optical observations
  20. GRB030324, BVRcIc field photometry
  21. GRB030323, BVRcIc field calibration
  22. Possible GRB 030320 localized by INTEGRAL
  23. GRB030226, BVRc observations
  24. Chandra detection of the X-ray afterglow of GRB 030226
  25. GRB 030226: Ic Observations
  26. GRB030227: Kiso optical upper limit
  27. GRB030227, BVRcIc field photometry
  28. GRB030226, BVRcIc field calibration
  29. GRB 030228, optical observations
  30. GRB 030227: Confirmed Optical Afterglow (S1-A)
  31. GRB 030227: fading of candidate optical afterglow 'S1-A'
  32. GRB030227:Optical observations
  33. GRB 030227, possible optical counterpart of XMM-Newton source
  34. GRB030227: Kiso optical observations
  35. GRB 030227: Kyoto optical observation
  36. GRB030227 localized by INTEGRAL
  37. Possible break in the GRB 030226 light curve
  38. GRB030226: ESI spectroscopy
  39. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  40. GRB 030226 simultaneous optical observations
  41. GRB 030226, optical observations
  42. GRB030226: Optical decay index
  43. GRB 030217: Optical Observations at 4, 5, and 6 Days
  44. GRB 030131: marginal optical detection
  45. GRB 030204: Optical Observations
  46. GRB030204 field photometry
  47. GRB020819: Kiso R and I band observations
  48. GRB030131: Candidate Optical Afterglow
  49. GRB 030131, optical observations
  50. GRB 030131: afterglow candidate
  51. GRB 030115, late-time optical observations
  52. GRB030131: corrected INTEGRAL position
  53. GRB 020819: Host galaxy at Radio Position
  54. IPN triangulation of GRB030131
  55. GRB 030131 optical observations
  56. GRB030131: refined position
  57. GRB 030131 optical observations
  58. A long GRB detected by INTEGRAL
  59. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  60. GRB 030115, simultaneous observations by BOOTES-1
  61. GRB 030115: IR observations with IRSF/SIRIUS
  62. GRB030115, afterglow candidate
  63. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  64. GRB 030115 : Possible IR counterpart
  65. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  66. GRB 030115: APO Optical Observations
  67. IPN triangulation of GRB030102 (annulus)
  68. VLT spectroscopy of the probable host of GRB 021211
  69. GRB 021211: Probable Host and Underlying Supernova
  70. GRB 021112: Evidence for Another Dark Optical Afterglow
  71. GRB 021219: OSN optical observations
  72. GRB021219, optical observations
  73. GRB021219, optical observation by MASTER
  74. GRB021219: a long GRB localized by INTEGRAL
  75. GRB021211: APO optical observations
  76. IPN detection of continued activity from SGR1806-20
  77. XRF 020903 : HST observations
  78. GRB 021201: Optical Observations
  79. GRB 021211: CTIO observations
  80. GRB 021211: early break in light curve
  81. GRB021211, BVRI field photometry
  82. GRB021211: Optical observations in CrAO
  83. GRB 021211, optical observations
  84. GRB021211: Kiso Observations
  85. GRB 021201, optical observations
  86. GRB021211: Optical observations
  87. GRB 021201 (short/hard), NOT observations
  88. Chandra observation of the IPN error box of GRB021201 (short/hard)
  89. GRB 021211, R- and I-band observations
  90. GRB021211 - Upper limits from recent and historical observations
  91. GRB 021204: I-band Observations
  92. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  93. GRB 021125: Radio Observations
  94. IPN detection of renewed activity from SGR1806-20
  95. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  96. GRB021201, BVRcIc field photometry
  97. GRB 021201: BOOTES simultaneous optical observations
  98. GRB021004, late time optical observations
  99. GRB021125 : A long GRB localized by INTEGRAL
  100. GRB 021112: Afterglow or Variable Star?

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