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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

28278 results found.

  1. LIGO/Virgo/KAGRA S241231bg: NED Galaxies in the Localization Volume
  2. LIGO/Virgo/KAGRA S241230bd: Updated Sky localization
  3. GRB 241228B: Multiband optical monitoring with 1.6m Mephisto
  4. GRB 241229B: SVOM/GRM observation
  5. LIGO/Virgo/KAGRA S241231bg: Identification of a GW compact binary merger candidate
  6. EP241217A: J band upper limit by SYSU 80cm telescope
  7. LIGO/Virgo/KAGRA S241230ev: Identification of a GW compact binary merger candidate
  8. GRB 241229B: SAO RAS optical upper limit
  9. GRB 241228B: SAO RAS optical observations
  10. GRB 241229A: SAO RAS optical observations
  11. IceCube-Cascade 241228A: Upper limits from a search for additional neutrino events in IceCube
  12. GRB 241229A: Swift-XRT observations
  13. EP240702a: 7DT Optical upper limits
  14. GRB 240606B: 7DT Optical upper limits
  15. LIGO/Virgo/KAGRA S241230bd: Identification of a GW compact binary merger candidate
  16. GRB 241229B: Swift-BAT refined analysis
  17. LIGO/Virgo/KAGRA S241225v: Updated Sky localization
  18. LIGO/Virgo/KAGRA S241225c: Updated Sky localization and EM Bright Classification
  19. GRB241229B: UVOT upper limits
  20. GRB 241228B: Fermi GBM Observation
  21. GRB 241228B: Swift-XRT afterglow detection
  22. GRB 241229B: Fermi GBM Observation
  23. GRB 241229B: NUTTelA-TAO / BSTI Optical Limits
  24. GRB 241228A: Mondy optical afterglow observations
  25. GRB 241229A: GOTO optical upper limits
  26. GRB 241228B: VLT/X-shooter redshift of z = 2.674
  27. GRB 241228A: NOT optical upper limits
  28. GRB 241228B: LCO optical observation
  29. GRB 241228A: Swift-BAT refined analysis
  30. GRB 241228B: Swift/BAT-GUANO localization skymap of a burst
  31. GRB 241228A: Fermi GBM Observation
  32. GRB241228B: GROWTH-India Telescope optical observations
  33. GRB 241228B: LCOGT photometry of the likely optical counterpart GOTO24jmz
  34. GRB 241226A: Swift/BAT-GUANO localization skymap of a burst
  35. GRB 241228A: GROWTH-India telescope optical upper limit
  36. GRB 241228B: TRT optical counterpart confirmation
  37. GRB 241228A: Swift-XRT refined Analysis
  38. GRB 241228A: Swift/UVOT Upper Limits
  39. GRB 241228A: Enhanced Swift-XRT position
  40. GRB 241228A: Swift detection of a burst
  41. IceCube-241224A: Upper limits from a search for additional neutrino events in IceCube
  42. LIGO/Virgo/KAGRA S241225c: Two counterpart neutrino candidates from IceCube neutrino searches
  43. GRB 241212A: VZLUSAT-2 detection
  44. EP241223a: Mondy AZT-33IK optical observations
  45. GRB 241029A: LCO optical observation
  46. GRB 241223A: Swift-XRT observations
  47. LIGO/Virgo/KAGRA S241225v: Identification of a GW compact binary merger candidate
  48. GRB 241029A: AbAO AS-32 optical observations
  49. GRB 241223A: Fermi GBM Detection
  50. Fermi trigger No 756678579: Global MASTER-Net observations report
  51. LIGO/Virgo/KAGRA S241225c: Identification of a GW compact binary merger candidate
  52. EP241223a
  53. EP241223a: EP-WXT detection of a fast X-ray transient
  54. EP241113a: Non-detection in Radio Follow-up Observations with eMERLIN
  55. GRB241113A: 7DT Optical upper limits
  56. GRB 241223A: GOTO optical observations summary
  57. GRB 241105A: JWST photometric observations of the host galaxy
  58. EP241217a: e-MERLIN radio observations
  59. GRB 241223A: BALROG localization (Fermi Trigger 756648531 / GRB 241223506)
  60. The EP-WXT trigger 01709129287 is likely a flaring star
  61. EP241217a: Liverpool Telescope optical upper limit
  62. EP241021a: VLA radio detection
  63. GRB 241218A: Mondy AZT-33IK optical upper limit
  64. EP241217a : Leavitt Observatory optical upper limit
  65. GRB 241217A/EP241217b: tentative VLT spectroscopic redshift z=1.879
  66. EP241217a: 1.6m Mephisto multi-band optical observations
  67. GRB 241217a/EP241217B: 1.6m Mephisto optical upper limits
  68. GRB 241218A: Swift/UVOT Upper Limits
  69. EP241217a: optical upper limit with the Liverpool Telescope
  70. GRB 241209B: EP-FXT afterglow detection
  71. GRB 241218A: NOT optical upper limits
  72. GRB 241218A: Swift-BAT refined analysis
  73. GRB 241217A / EP241217B: GRANDMA/T1MPicduMidi optical upperlimits
  74. EP 241217a: NIR detection with P200/WIRC
  75. EP 241217a: Possible J-band detection with WINTER
  76. GRB 241217A/EP241217B: Fermi-GBM Sub-Threshold Detection
  77. EP241217a: refined EP-WXT analysis and EP-FXT follow-up observations
  78. GRB 241217A / EP241217b: Nanshan/HMT optical upper limit
  79. GRB 241217A / EP241217b: NOT optical upper limits
  80. GRB 241218A: REM optical upper limit
  81. GRB 241217A/EP241217b: REM optical/NIR upper limits
  82. EP241217a: REM optical/NIR upper limits
  83. GRB 241217a: Liverpool Telescope optical follow-up
  84. EP241217a: Liverpool Telescope optical follow-up
  85. GRB 241218A: Swift-XRT refined Analysis
  86. EP241217a: NOT optical observations
  87. EP241217a: GROWTH-India Telescope optical observations
  88. GRB 241218A: NUTTelA-TAO / BSTI Optical Limits
  89. EP241119a: 7DT Optical upper limits
  90. EP241217a: Xinglong optical follow-up observations
  91. EP241217b/GRB 241217A: EP detection of the prompt X-ray emssion
  92. GRB 241218A: LCOGT Optical Upper Limit
  93. GRB 241218A: Enhanced Swift-XRT position
  94. GRB 241217A: GMG Optical Upper Limit
  95. GRB 241218A: Swift detection of a burst
  96. GRB 241217A : SVOM/VT optical afterglow detection
  97. GRB 241217A: Swift-XRT afterglow detection
  98. GRB 241217A: LCO optical upper limit
  99. GRB 241217A: GRANDMA/TAROT optical upperlimits
  100. EP241217a: Swift-XRT Detection

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