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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"

20967 results found.

  1. GRB 120320A: Zadko optical observations
  2. GRB 120316A: Fermi-GBM and Fermi-LAT Observations
  3. GRB 120229A: Magellan observations and limit on an optical afterglow
  4. GRB 120320A: Swift/UVOT Upper Limits
  5. GRB 120320A , optical observations
  6. GRB 120320A: Gemini-N and UKIRT observations
  7. GRB 120320A: MASTER optical observations
  8. GRB 111228A: possible detection of the SN with the TNG
  9. GRB 120302A: Swift XRT refined analysis
  10. GRB 120312A: Gemini and UKIRT imaging
  11. GRB 120311A: C88 optical limits
  12. GRB 120312A: Swift/UVOT Upper Limits
  13. GRB 120312A: MASTER-NET optical observations
  14. GRB 120312A: NOT observations
  15. GRB 120311A: VLT/X-shooter observations
  16. GRB 120311B: C88 optical limits
  17. GROND observations of GRB 120311A
  18. GRB 120311B: Swift/UVOT Upper Limits
  19. GRB 120311B: Faulkes Telescope North observations
  20. GRB 120311B: Swift-XRT observations
  21. GRB 120311A: Swift/UVOT Upper Limits
  22. GRB 120311A: CAHA 1.23m I-band early observations
  23. GRB 120311A: Swift-XRT observations
  24. GRB 120311A: Liverpool Telescope optical candidate
  25. GRB 120308A: RTT150 optical observations
  26. GRB 120302A: RTT150 optical observations
  27. GRB 120308A: 1.23m CAHA I-band observations
  28. GRB 120308A: Further PAIRITEL NIR Observations
  29. GRB 120308A: Swift/UVOT Detection
  30. GRB 120308A: IAC80 I-band observations
  31. GRB 120308A: PAIRITEL NIR observations
  32. GRB 120308A: Liverpool Telescope optical afterglow candidate
  33. GRB 120305A: Swift/UVOT Upper Limits
  34. GRB 120305A: EVLA deep limit on a radio counterpart
  35. GRB 120305A - Liverpool Telescope Observations
  36. GRB 120305A: MASTER-NET early optical observations
  37. GRB 120302A: GROND detection of an afterglow candidate
  38. GRB 111222A: Swift observation on 2012 February 06/07
  39. GRB 120226A: Fermi-LAT data analysis
  40. GRB 120224A: VLT/X-shooter observations
  41. GRB 120224A: GROND detection of the afterglow candidate
  42. GRB 120224A: Swift/UVOT Upper Limits
  43. GRB 120224A: FTN optical observations
  44. GRB 120219A: 1.23m CAHA optical observations
  45. GCN 12974 : Errata in the Subject
  46. GRB 120219A, optical observations
  47. GRB120219A: Keck Observations
  48. GRB 120219A: Swift/UVOT Upper Limits
  49. GRB120219A: TNT optical afterglow candidates
  50. GRB 120219A: MASTER-NET prompt and early optical observations
  51. GRB 120215A: Swift/UVOT Upper Limits
  52. Skynet/PROMPT observations of GRB120215A
  53. GRB 120211A : LOAO optical observations
  54. GRB 120213A: Swift/UVOT Upper Limits
  55. GRB 120212A: GMG optical observation
  56. GRB 120213A: MASTER-NET early optical observations
  57. GRB 120212A: Swift/UVOT Detection
  58. GRB 120211A: MITSuME Okayama Ks-band Observation
  59. GRB 120212A: Swift-XRT observations
  60. GRB 120211A: GROND Upper limits
  61. GRB 120211A, optical observations
  62. GRB 120211A: Swift/UVOT Upper Limits
  63. GRB 120211A: MASTER early optical observations
  64. GRB 120211A: MITSuME Okayama Ks-band upper limit
  65. GRB 120211A - Faulkes Telescope South Observations
  66. GRB 120202A: MASTER early optical observations
  67. Swift detection of a burst from LS I +61 303
  68. GRB 120202A: GROND observations
  69. GRB 120202A: Swift/XRT and UVOT observations
  70. GRB 120202A: TAROT Calern observatory optical observations
  71. GRB 111228A: Possible host detected by Swift/UVOT
  72. GRB 120129A: MASTER optical observations
  73. GRB 120127A / P48 Imaging
  74. GRB 120127A: MASTER optical observations
  75. GRB 120127A: MAXI/GSC detection of a probable GRB
  76. GRB 120119A : LOAO Optical Observations
  77. GRB 120119A: EVLA observations
  78. GRB 111225A: optical observations
  79. GRB 120121A: Swift/UVOT Upper Limits
  80. GRB 120121A: ISON-NM optical observations
  81. GRB 120119A: TAROT La Silla observatory optical observations
  82. GRB120119A: REM NIR observations
  83. GRB 120119A: optical observations
  84. GRB 120119A: Swift/UVOT Observations
  85. GRB 120118B: RTT150 optical observations
  86. GRB 120119A: SMARTS optical/IR afterglow observations
  87. GRB 120119A: optical observations
  88. GRB 120118B: TNG NIR observations
  89. GRB 120118B : Lulin Optical limit
  90. GRB 120119A: PROMPT optical observation of early afterglow
  91. GRB 120119A: GROND Detection of the Optical/NIR Afterglow
  92. GRB 120118B: Swift/UVOT Upper Limits
  93. GRB 120119A: Liverpool Telescope afterglow detection
  94. GRB 120119A: PAIRITEL NIR Detection
  95. GRB 120118B: NOT observations
  96. GRB 120118B: Faulkes Telescope South observations
  97. GRB 120118B: MASTER optical observations
  98. XRF 120118A: Optical candidate
  99. GRB 120116A: Swift/UVOT Upper Limits
  100. AXP 4U 1042+61: Mondy optical observations

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